G2Cdb::Gene report

Gene id
G00001394
Gene symbol
MAPK8IP1 (HGNC)
Species
Homo sapiens
Description
mitogen-activated protein kinase 8 interacting protein 1
Orthologue
G00000145 (Mus musculus)

Databases (7)

Gene
ENSG00000121653 (Ensembl human gene)
9479 (Entrez Gene)
53 (G2Cdb plasticity & disease)
MAPK8IP1 (GeneCards)
Literature
604641 (OMIM)
Marker Symbol
HGNC:6882 (HGNC)
Protein Sequence
Q9UQF2 (UniProt)

Synonyms (3)

  • IB1
  • JIP-1
  • JIP1

Diseases (2)

Disease Nervous effect Mutations Found Literature Mutations Type Genetic association?
D00000142: Diabetes mellitus Type 2 N Y (10700186) Microinsertion (MI) Y
D00000193: Alzheimer's disease Y Y (12740599) Single nucleotide polymorphism (SNP) Y

References

  • Islet-brain1/C-Jun N-terminal kinase interacting protein-1 (IB1/JIP-1) promoter variant is associated with Alzheimer's disease.

    Helbecque N, Abderrahamani A, Meylan L, Riederer B, Mooser V, Miklossy J, Delplanque J, Boutin P, Nicod P, Haefliger JA, Cottel D, Amouyel P, Froguel P, Waeber G and Abderrhamani A

    Institut National de la Santé et de la Recherche Médicale U508, Pasteur Institute, Lille, France.

    Islet-brain1 (IB1) or c-Jun NH2 terminal kinase interacting protein-1 (JIP-1), the product of the MAPK8IP1 gene, functions as a neuronal scaffold protein to allow signalling specificity. IB1/JIP-1 interacts with many cellular components including the reelin receptor ApoER2, the low-density lipoprotein receptor-related protein (LRP), kinesin and the Alzheimer's amyloid precursor protein. Coexpression of IB1/JIP-1 with other components of the c-Jun NH2 terminal-kinase (JNK) pathway activates the JNK activity; conversely, selective disruption of IB1/JIP-1 in mice reduces the stress-induced apoptosis of neuronal cells. We therefore hypothesized that IB1/JIP-1 is a risk factor for Alzheimer's disease (AD). By immunocytochemistry, we first colocalized the presence of IB1/JIP-1 with JNK and phosphorylated tau in neurofibrillary tangles. We next identified a -499A>G polymorphism in the 5' regulatory region of the MAPK8IP1 gene. In two separate French populations the -499A>G polymorphism of MAPK8IP1 was not associated with an increased risk to AD. However, when stratified on the +766C>T polymorphism of exon 3 of the LRP gene, the IB1/JIP-1 polymorphism was strongly associated with AD in subjects bearing the CC genotype in the LRP gene. The functional consequences of the -499A>G polymorphism of MAPK8IP1 was investigated in vitro. In neuronal cells, the G allele increased transcriptional activity and was associated with an enhanced binding activity. Taken together, these data indicate that the increased transcriptional activity in the presence of the G allele of MAPK8IP1 is a risk factor to the onset of in patients bearing the CC genotype of the LRP gene.

    Funded by: Medical Research Council: G0000477

    Molecular psychiatry 2003;8;4;413-22, 363

  • The gene MAPK8IP1, encoding islet-brain-1, is a candidate for type 2 diabetes.

    Waeber G, Delplanque J, Bonny C, Mooser V, Steinmann M, Widmann C, Maillard A, Miklossy J, Dina C, Hani EH, Vionnet N, Nicod P, Boutin P and Froguel P

    Department of Internal Medicine, CHUV-University Hospital, Lausanne, Switzerland. gwaeber@chuv.hospvd.ch

    Type 2 diabetes is a polygenic and genetically heterogeneous disease . The age of onset of the disease is usually late and environmental factors may be required to induce the complete diabetic phenotype. Susceptibility genes for diabetes have not yet been identified. Islet-brain-1 (IB1, encoded by MAPK8IP1), a novel DNA-binding transactivator of the glucose transporter GLUT2 (encoded by SLC2A2), is the homologue of the c-Jun amino-terminal kinase-interacting protein-1 (JIP-1; refs 2-5). We evaluated the role of IBi in beta-cells by expression of a MAPK8IP1 antisense RNA in a stable insulinoma beta-cell line. A 38% decrease in IB1 protein content resulted in a 49% and a 41% reduction in SLC2A2 and INS (encoding insulin) mRNA expression, respectively. In addition, we detected MAPK8IP1 transcripts and IBi protein in human pancreatic islets. These data establish MAPK8IP1 as a candidate gene for human diabetes. Sibpair analyses performed on i49 multiplex French families with type 2 diabetes excluded MAPK8IP1 as a major diabetogenic locus. We did, however, identify in one family a missense mutation located in the coding region of MAPK8IP1 (559N) that segregated with diabetes. In vitro, this mutation was associated with an inability of IB1 to prevent apoptosis induced by MAPK/ERK kinase kinase 1 (MEKK1) and a reduced ability to counteract the inhibitory action of the activated c-JUN amino-terminal kinase (JNK) pathway on INS transcriptional activity. Identification of this novel non-maturity onset diabetes of the young (MODY) form of diabetes demonstrates that IB1 is a key regulator of 3-cell function.

    Nature genetics 2000;24;3;291-5

Literature (51)

Pubmed - other

  • Role of the JNK-interacting protein 1/islet brain 1 in cell degeneration in Alzheimer disease and diabetes.

    Beeler N, Riederer BM, Waeber G and Abderrahmani A

    Service of Internal Medicine, Centre Hospitalier Universitaire Vaudois and University of Lausanne, CH-1011 Lausanne, Switzerland.

    Numerous epidemiological studies and some pharmacological clinical trials show the close connection between Alzheimer disease (AD) and type 2 diabetes (T2D) and thereby, shed more light into the existence of possible similar pathogenic mechanisms between these two diseases. Diabetes increases the risk of developing AD and sensitizers of insulin currently used as diabetes drugs can efficiently slow cognitive decline of the neurological disorder. Deposits of amyloid aggregate and hyperphosphorylation of tau, which are hallmarks of AD, have been also found in degenerating pancreatic islets beta-cells of patients with T2D. These events may have a causal role in the pathogenesis of the two diseases. Increased c-Jun NH(2)-terminal kinase (JNK) activity is found in neurofibrillary tangles (NFT) of AD and promotes programmed cell death of beta-cells exposed to a diabetic environment. The JNK-interacting protein 1 (JIP-1), also called islet brain 1 (IB1) because it is mostly expressed in the brain and islets, is a key regulator of the JNK pathway in neuronal and beta-cells. JNK, hyperphosphorylated tau and IB1/JIP-1 all co-localize with amyloids deposits in NFT and islets of AD and patients with T2D. This review discusses the role of the IB1/JIP-1 and the JNK pathway in the molecular pathogenesis of AD and T2D.

    Brain research bulletin 2009;80;4-5;274-81

  • Phosphorylated Tau interacts with c-Jun N-terminal kinase-interacting protein 1 (JIP1) in Alzheimer disease.

    Ittner LM, Ke YD and Götz J

    Alzheimer's and Parkinson's Disease Laboratory, Brain and Mind Research Institute, University of Sydney, Sydney, Camperdown, New South Wales 2050, Australia.

    In Alzheimer disease (AD) and frontotemporal dementia the microtubule-associated protein Tau becomes progressively hyperphosphorylated, eventually forming aggregates. However, how Tau dysfunction is associated with functional impairment is only partly understood, especially at early stages when Tau is mislocalized but has not yet formed aggregates. Impaired axonal transport has been proposed as a potential pathomechanism, based on cellular Tau models and Tau transgenic mice. We recently reported K369I mutant Tau transgenic K3 mice with axonal transport defects that suggested a cargo-selective impairment of kinesin-driven anterograde transport by Tau. Here, we show that kinesin motor complex formation is disturbed in the K3 mice. We show that under pathological conditions hyperphosphorylated Tau interacts with c-Jun N-terminal kinase- interacting protein 1 (JIP1), which is associated with the kinesin motor protein complex. As a result, transport of JIP1 into the axon is impaired, causing JIP1 to accumulate in the cell body. Because we found trapping of JIP1 and a pathological Tau/JIP1 interaction also in AD brain, this may have pathomechanistic implications in diseases with a Tau pathology. This is supported by JIP1 sequestration in the cell body of Tau-transfected primary neuronal cultures. The pathological Tau/JIP1 interaction requires phosphorylation of Tau, and Tau competes with the physiological binding of JIP1 to kinesin light chain. Because JIP1 is involved in regulating cargo binding to kinesin motors, our findings may, at least in part, explain how hyperphosphorylated Tau mediates impaired axonal transport in AD and frontotemporal dementia.

    The Journal of biological chemistry 2009;284;31;20909-16

  • Evidence for a role of the amyloid precursor protein in thyroid carcinogenesis.

    Krause K, Karger S, Sheu SY, Aigner T, Kursawe R, Gimm O, Schmid KW, Dralle H and Fuhrer D

    Division of Endocrinology, Department of Internal Medicine, University of Leipzig, Ph.-Rosenthal-Str. 27, D-04103 Leipzig, Germany.

    We have recently found an increased expression of amyloid precursor protein (APP) in cold thyroid nodules that are difficult to classify as a truly benign thyroid neoplasm or a lesion with the potential for further dedifferentiation. Since differences in APP activity have been found in other human cancers, we asked whether thyroid carcinogenesis might be associated with an altered APP expression and function. APP regulation was studied in vitro in differentiated (FRTL-5) and dedifferentiated follicular thyroid carcinomas (FTC-133) thyroid cells after specific inhibition or activation of the cAMP-PKA, the PI3K/AKT or the protein kinase c (PKC) cascades. In vivo analysis of APP expression and downstream signalling was performed in benign and malignant thyroid tissues. We found that upregulation of APP expression and sAPP secretion is induced by TSH in differentiated thyroid cells and by insulin in thyroid cancer cells. PKC is a strong activator of APP cleavage and in FTC-133 confers prolonged release of the APP ectodomain. FTC-133 but not FRTL-5 cells show a prominent cell surface expression of the APP ectodomain, which has been suggested to function as an autocrine growth factor. Thyroid cancers are characterized by APP upregulation, increased membrane targeting of the APP ectodomain and significantly increased mRNA levels of the APP scaffold proteins JIP1, ShcA and Fe65.

    The Journal of endocrinology 2008;198;2;291-9

  • Modulation of interleukin-1 transcriptional response by the interaction between VRK2 and the JIP1 scaffold protein.

    Blanco S, Sanz-García M, Santos CR and Lazo PA

    Programa de Oncología Traslacional, Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Salamanca, Salamanca, Spain.

    Background: Cellular biological responses to specific stimulation are determined by a balance among signaling pathways. Protein interactions are likely to modulate these pathways. Vaccinia-related kinase-2 (VRK2) is a novel human kinase that can modulate different signaling pathways.

    We report that in vivo, the activity of JIP1-JNK complexes is downregulated by VRK2 in response to interleukin-1beta. Also the reduction of endogenous VRK2 with shRNA increases the transcriptional response to IL-1beta. The JIP1 scaffold protein assembles three consecutive members of a given MAPK pathway forming signaling complexes and their signal can be modulated by interactions with regulatory proteins that remain to be identified. Knocking-down JIP1 with siRNA resulted in elimination of the AP1 transcriptional response to IL-1beta. VRK2, a member of novel Ser-Thr kinase family, is able to stably interact with JIP1, TAK1 and MKK7, but not JNK, and can be isolated forming oligomeric complexes with different proportions of TAK1, MKK7beta1 and JNK. JIP1 assembles all these proteins in an oligomeric signalosome. VRK2 binding to the JIP1 signalosome prevents the association of JNK and results in a reduction in its phosphorylation and downregulation of AP1-dependent transcription.

    This work suggests that the intracellular level of VRK2 protein can modulate the flow through a signaling pathway and alter the response from a receptor that can be distributed by more than one pathway, and thus contribute to the cellular specificity of the response by forming alternative signaling complexes. Furthermore, the effect might be more general and affect other signaling routes assembled on the JIP1 scaffold protein for which a model is proposed.

    PloS one 2008;3;2;e1660

  • Vaccinia-related kinase 2 modulates the stress response to hypoxia mediated by TAK1.

    Blanco S, Santos C and Lazo PA

    Programa de Oncología Translacional, Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas-Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca E-37007, Spain.

    Hypoxia represents a major stress that requires an immediate cellular response in which different signaling pathways participate. Hypoxia induces an increase in the activity of TAK1, an atypical mitogen-activated protein kinase kinase kinase (MAPKKK), which responds to oxidative stress by triggering cascades leading to the activation of c-Jun N-terminal kinase (JNK). JNK activation by hypoxia requires assembly with the JIP1 scaffold protein, which might also interact with other intracellular proteins that are less well known but that might modulate MAPK signaling. We report that TAK1 is able to form a stable complex with JIP1 and thus regulate the activation of JNK, which in turn determines the cellular stress response to hypoxia. This activation of TAK1-JIP1-JNK is suppressed by vaccinia-related kinase 2 (VRK2). VRK2A is able to interact with TAK1 by its C-terminal region, forming stable complexes. The kinase activity of VRK2 is not necessary for this interaction or the downregulation of AP1-dependent transcription. Furthermore, reduction of the endogenous VRK2 level with short hairpin RNA can increase the response induced by hypoxia, suggesting that the intracellular levels of VRK2 can determine the magnitude of this stress response.

    Molecular and cellular biology 2007;27;20;7273-83

  • Two binding partners cooperate to activate the molecular motor Kinesin-1.

    Blasius TL, Cai D, Jih GT, Toret CP and Verhey KJ

    Department of Cell Biology, University of Michigan, Ann Arbor, MI 48109, USA.

    The regulation of molecular motors is an important cellular problem, as motility in the absence of cargo results in futile adenosine triphosphate hydrolysis. When not transporting cargo, the microtubule (MT)-based motor Kinesin-1 is kept inactive as a result of a folded conformation that allows autoinhibition of the N-terminal motor by the C-terminal tail. The simplest model of Kinesin-1 activation posits that cargo binding to nonmotor regions relieves autoinhibition. In this study, we show that binding of the c-Jun N-terminal kinase-interacting protein 1 (JIP1) cargo protein is not sufficient to activate Kinesin-1. Because two regions of the Kinesin-1 tail are required for autoinhibition, we searched for a second molecule that contributes to activation of the motor. We identified fasciculation and elongation protein zeta1 (FEZ1) as a binding partner of kinesin heavy chain. We show that binding of JIP1 and FEZ1 to Kinesin-1 is sufficient to activate the motor for MT binding and motility. These results provide the first demonstration of the activation of a MT-based motor by cellular binding partners.

    Funded by: NIGMS NIH HHS: GM070862, R01 GM070862, R01 GM070862-02

    The Journal of cell biology 2007;176;1;11-7

  • A unique set of SH3-SH3 interactions controls IB1 homodimerization.

    Kristensen O, Guenat S, Dar I, Allaman-Pillet N, Abderrahmani A, Ferdaoussi M, Roduit R, Maurer F, Beckmann JS, Kastrup JS, Gajhede M and Bonny C

    Biostructural Research, Department of Medicinal Chemistry, The Danish University of Pharmaceutical Sciences, Copenhagen, Denmark. ok@dfuni.dk

    Islet-brain 1 (IB1 or JIP-1) is a scaffold protein that interacts with components of the c-Jun N-terminal kinase (JNK) signal-transduction pathway. IB1 is expressed at high levels in neurons and in pancreatic beta-cells, where it controls expression of several insulin-secretory components and secretion. IB1 has been shown to homodimerize, but neither the molecular mechanisms nor the function of dimerization have yet been characterized. Here, we show that IB1 homodimerizes through a novel and unique set of Src homology 3 (SH3)-SH3 interactions. X-ray crystallography studies show that the dimer interface covers a region usually engaged in PxxP-mediated ligand recognition, even though the IB1 SH3 domain lacks this motif. The highly stable IB1 homodimer can be significantly destabilized in vitro by three individual point mutations directed against key residues involved in dimerization. Each mutation reduces IB1-dependent basal JNK activity in 293T cells. Impaired dimerization also results in a reduction in glucose transporter type 2 expression and in glucose-dependent insulin secretion in pancreatic beta-cells. Taken together, these results indicate that IB1 homodimerization through its SH3 domain has pleiotropic effects including regulation of the insulin secretion process.

    The EMBO journal 2006;25;4;785-97

  • Coordinated transport of phosphorylated amyloid-beta precursor protein and c-Jun NH2-terminal kinase-interacting protein-1.

    Muresan Z and Muresan V

    Department of Physiology and Biophysics, Case School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA. zoia.muresan@case.edu

    The transmembrane protein amyloid-beta precursor protein (APP) and the vesicle-associated protein c-Jun NH(2)-terminal kinase-interacting protein-1 (JIP-1) are transported into axons by kinesin-1. Both proteins may bind to kinesin-1 directly and can be transported separately. Because JIP-1 and APP can interact, kinesin-1 may recruit them as a complex, enabling their cotransport. In this study, we tested whether APP and JIP-1 are transported together or separately on different vesicles. We found that, within the cellular context, JIP-1 preferentially interacts with Thr(668)-phosphorylated APP (pAPP), compared with nonphosphorylated APP. In neurons, JIP-1 colocalizes with vesicles containing pAPP and is excluded from those containing nonphosphorylated APP. The accumulation of JIP-1 and pAPP in neurites requires kinesin-1, and the expression of a phosphomimetic APP mutant increases JIP-1 transport. Down-regulation of JIP-1 by small interfering RNA specifically impairs transport of pAPP, with no effect on the trafficking of nonphosphorylated APP. These results indicate that the phosphorylation of APP regulates the formation of a pAPP-JIP-1 complex that accumulates in neurites independent of nonphosphorylated APP.

    Funded by: NIA NIH HHS: AG08012, P50 AG008012; NIGMS NIH HHS: 5R01GM068596-02, R01 GM068596

    The Journal of cell biology 2005;171;4;615-25

  • A human protein-protein interaction network: a resource for annotating the proteome.

    Stelzl U, Worm U, Lalowski M, Haenig C, Brembeck FH, Goehler H, Stroedicke M, Zenkner M, Schoenherr A, Koeppen S, Timm J, Mintzlaff S, Abraham C, Bock N, Kietzmann S, Goedde A, Toksöz E, Droege A, Krobitsch S, Korn B, Birchmeier W, Lehrach H and Wanker EE

    Max Delbrueck Center for Molecular Medicine, 13092 Berlin-Buch, Germany.

    Protein-protein interaction maps provide a valuable framework for a better understanding of the functional organization of the proteome. To detect interacting pairs of human proteins systematically, a protein matrix of 4456 baits and 5632 preys was screened by automated yeast two-hybrid (Y2H) interaction mating. We identified 3186 mostly novel interactions among 1705 proteins, resulting in a large, highly connected network. Independent pull-down and co-immunoprecipitation assays validated the overall quality of the Y2H interactions. Using topological and GO criteria, a scoring system was developed to define 911 high-confidence interactions among 401 proteins. Furthermore, the network was searched for interactions linking uncharacterized gene products and human disease proteins to regulatory cellular pathways. Two novel Axin-1 interactions were validated experimentally, characterizing ANP32A and CRMP1 as modulators of Wnt signaling. Systematic human protein interaction screens can lead to a more comprehensive understanding of protein function and cellular processes.

    Cell 2005;122;6;957-68

  • IB1/JIP-1 controls JNK activation and increased during prostatic LNCaP cells neuroendocrine differentiation.

    Tawadros T, Martin D, Abderrahmani A, Leisinger HJ, Waeber G and Haefliger JA

    Service of Urology, University Hospital, Lausanne, Switzerland.

    The scaffold protein Islet-Brain1/c-Jun amino-terminal kinase Interacting Protein-1 (IB1/JIP-1) is a modulator of the c-Jun N-terminal kinase (JNK) activity, which has been implicated in pleiotrophic cellular functions including cell differentiation, division, and death. In this study, we described the presence of IB1/JIP-1 in epithelium of the rat prostate as well as in the human prostatic LNCaP cells. We investigated the functional role of IB1/JIP-1 in LNCaP cells exposed to the proapoptotic agent N-(4-hydroxyphenyl)retinamide (4-HPR) which induced a reduction of IB1/JIP-1 content and a concomittant increase in JNK activity. Conversely, IB1/JIP-1 overexpression using a viral gene transfer prevented the JNK activation and the 4-HPR-induced apoptosis was blunted. In prostatic adenocarcinoma cells, the neuroendocrine (NE) phenotype acquisition is associated with tumor progression and androgen independence. During NE transdifferentiation of LNCaP cells, IB1/JIP-1 levels were increased. This regulated expression of IB1/JIP-1 is secondary to a loss of the neuronal transcriptional repressor neuron restrictive silencing factor (NRSF/REST) function which is known to repress IB1/JIP-1. Together, these results indicated that IB1/JIP-1 participates to the neuronal phenotype of the human LNCaP cells and is a regulator of JNK signaling pathway.

    Cellular signalling 2005;17;8;929-39

  • Cross-talk between JIP3 and JIP1 during glucose deprivation: SEK1-JNK2 and Akt1 act as mediators.

    Song JJ and Lee YJ

    Department of Surgery and Pharmacology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA.

    We have previously observed that glucose deprivation activates the ASK1-MEK-MAPK signal transduction pathway. In the present study, we reveal that two scaffolding proteins, JIP1 and JIP3, have a cross-talk that leads to the regulation of the ASK1-SEK1-JNK signal during glucose deprivation. Glucose deprivation rapidly increases the interaction between ASK1 and JIP3, and the consequently activated ASK1 phosphorylates SEK1 on the Thr-261 residue. The activated SEK1 dissociates from JIP3 and phosphorylates JNK2 on the Tyr-185 residue. Phosphorylated JNK2 binds to JIP1, and the phosphorylation of the Thr-183 residue of JNK2 occurs. JNK2 phosphorylates JIP1 on the Thr-103 residue and leads to dissociation of Akt1 from JIP1. Dissociated Akt1 binds to SEK1 and ASK1 and inhibits their enzyme activity by phosphorylating SEK1 on the Ser-80 residue and ASK1 on the Ser-83 residue. Taken together, our data demonstrate that cross-talk between JIP3 and JIP1 is mediated through SEK1-JNK2 and Akt1.

    Funded by: NCI NIH HHS: CA95191, CA96989

    The Journal of biological chemistry 2005;280;29;26845-55

  • Dissociation of Akt1 from its negative regulator JIP1 is mediated through the ASK1-MEK-JNK signal transduction pathway during metabolic oxidative stress: a negative feedback loop.

    Song JJ and Lee YJ

    Department of Surgery and Pharmacology, University of Pittsburgh, Pittsburgh, PA 15213, USA.

    We have previously observed that metabolic oxidative stress-induced death domain-associated protein (Daxx) trafficking is mediated by the ASK1-SEK1-JNK1-HIPK1 signal transduction pathway. The relocalized Daxx from the nucleus to the cytoplasm during glucose deprivation participates in a positive regulatory feedback loop by binding to apoptosis signal-regulating kinase (ASK) 1. In this study, we report that Akt1 is involved in a negative regulatory feedback loop during glucose deprivation. Akt1 interacts with c-Jun NH(2)-terminal kinase (JNK)-interacting protein (JIP) 1, and Akt1 catalytic activity is inhibited. The JNK2-mediated phosphorylation of JIP1 results in the dissociation of Akt1 from JIP1 and subsequently restores Akt1 enzyme activity. Concomitantly, Akt1 interacts with stress-activated protein kinase/extracellular signal-regulated kinase (SEK) 1 (also known as MKK4) and inhibits SEK1 activity. Knockdown of SEK1 leads to the inhibition of JNK activation, JIP1-JNK2 binding, and the dissociation of Akt1 from JIP1 during glucose deprivation. Knockdown of JIP1 also leads to the inhibition of JNK activation, whereas the knockdown of Akt1 promotes JNK activation during glucose deprivation. Altogether, our data demonstrate that Akt1 participates in a negative regulatory feedback loop by interacting with the JIP1 scaffold protein.

    Funded by: NCI NIH HHS: CA95191, CA96989, R01 CA095191, R01 CA096989

    The Journal of cell biology 2005;170;1;61-72

  • The JNK interacting protein JIP-1 and insulin like growth factor II genes are co-expressed in human embryonic tumours.

    Engström W, Rising A and Grip S

    Division of Pathology, Pharmacology and Toxicology, Department of Biomedical Sciences and Veterinary Public Health, Faculty of Veterinary Medicine, Swedish University of Agricultural Sciences, Uppsala, Sweden. wilhelm.engstrom@bvf.slu.se

    JNK interacting protein 1 (JIP-1) is a pivotal scaffolding protein in the JNK signalling pathway. It is believed to play a role in the mediation of mitogenic messages from the plasma membrane to the cell interior. Recent evidence suggests that the JIP-1 gene is co-regulated with the insulin like growth factor II (IGF II) gene, thereby contributing to the growth-promoting effects of this potent growth factor. In this study, fourteen embryonic tumours were examined for the expression of JIP-1 and IGF II. It was found that, irrespective of histological type and expression level, the two genes showed a high degree of co-variation in the sense that high IGF II expression was followed by high expression of JIP-1. This finding further supports the notion that JIP-1 and IGF II act in concert to enhance cell proliferation.

    Anticancer research 2005;25;2A;1075-8

  • JNK interacting protein 1 (JIP-1) protects LNCaP prostate cancer cells from growth arrest and apoptosis mediated by 12-0-tetradecanoylphorbol-13-acetate (TPA).

    Ikezoe T, Yang Y, Taguchi H and Koeffler HP

    Division of Hematology/Oncology, Cedars-Sinai Research Institute, University of California-Los Angeles School of Medicine, Los Angeles, CA 90048, USA. ikezoet@med.kochi-ms.ac.jp

    12-0-tetradecanoylphorbol-13-acetate (TPA) stimulates protein kinase C (PKC) which mediates apoptosis in androgen-sensitive LNCaP human prostate cancer cells. The downstream signals of PKC that mediate TPA-induced apoptosis in LNCaP cells are unclear. In this study, we found that TPA activates the c-Jun NH2-terminal kinase (JNK)/c-Jun/AP-1 pathway. To explore the possible role that the JNK/c-Jun/AP-1 signal pathway has on TPA-induced apoptosis in LNCaP cells, we stably transfected the scaffold protein, JNK interacting protein 1 (JIP-1), which binds to JNK inhibiting its ability to phosphorylate c-Jun. TPA (10(-9)-10(-7) mol l(-1)) caused phosphorylation of JNK in both wild-type and JIP-1-transfected (LNCaP-JIP-1) cells. It resulted in phosphorylation and upregulation of expression of c-Jun protein in the wild-type LNCaP cells, but not in the JIP-1-transfected LNCaP cells. In addition, upregulation of AP-1 reporter activity by TPA (10(-9) mol l(-1)) occurred in LNCaP cells but was abrogated in LNCaP-JIP-1 cells. Thus, TPA stimulated c-Jun through JNK, and JIP-1 effectively blocked JNK. TPA (10(-12)-10(-8) mol l(-1)) treatment of LNCaP cells caused their growth inhibition, cell cycle arrest, upregulation of p53 and p21waf1, and induction of apoptosis. All of these effects were significantly attenuated when LNCaP-JIP-1 cells were similarly treated with TPA. A previous study showed that c-Jun/AP-1 blocked androgen receptor (AR) signaling by inhibiting AR binding to AR response elements (AREs) of target genes including prostate-specific antigen (PSA). Therefore, we hypothesised that TPA would not be able to disrupt the AR signal pathway in LNCaP-JIP-1 cells. Contrary to expectation, TPA (10(-9)-10(-8) mol l(-1)) inhibited DHT-induced AREs reporter activity and decreased levels of PSA in the LNCaP-JIP-1 cells. Taken together, TPA, probably by stimulation of PKC, phosphorylates JNK, which phosphorylates and increases expression of c-Jun leading to AP-1 activity. Growth control of prostate cancer cells can be mediated through the JNK/c-Jun pathway, but androgen responsiveness of these cells can be independent of this pathway, suggesting that androgen independence in progressive prostate cancer may not occur through activation of this pathway.

    British journal of cancer 2004;90;10;2017-24

  • Calcium- and proteasome-dependent degradation of the JNK scaffold protein islet-brain 1.

    Allaman-Pillet N, Størling J, Oberson A, Roduit R, Negri S, Sauser C, Nicod P, Beckmann JS, Schorderet DF, Mandrup-Poulsen T and Bonny C

    Department of Internal Medicine, Centre Hospitalier Universitaire Vaudois, CH-1011 Lausanne, Switzerland. Nathalie.Pillet@chuv.hospvd.ch

    In models of type 1 diabetes, cytokines induce pancreatic beta-cell death by apoptosis. This process seems to be facilitated by a reduction in the amount of the islet-brain 1/JNK interacting protein 1 (IB1/JIP1), a JNK-scaffold with an anti-apoptotic effect. A point mutation S59N at the N terminus of the scaffold, which segregates in diabetic patients, has the functional consequence of sensitizing cells to apoptotic stimuli. Neither the mechanisms leading to IB1/JIP1 down-regulation by cytokines nor the mechanisms leading to the decreased capacity of the S59N mutation to protect cells from apoptosis are understood. Here, we show that IB1/JIP1 stability is modulated by intracellular calcium. The effect of calcium depends upon JNK activation, which primes the scaffold for ubiquitination-mediated degradation via the proteasome machinery. Furthermore, we observe that the S59N mutation decreases IB1/JIP1 stability by sensitizing IB1/JIP1 to calcium- and proteasome-dependent degradation. These data indicate that calcium influx initiated by cytokines mediates ubiquitination and degradation of IB1/JIP1 and may, therefore, provide a link between calcium influx and JNK-mediated apoptosis in pancreatic beta-cells.

    The Journal of biological chemistry 2003;278;49;48720-6

  • Amyloid beta protein precursor is phosphorylated by JNK-1 independent of, yet facilitated by, JNK-interacting protein (JIP)-1.

    Scheinfeld MH, Ghersi E, Davies P and D'Adamio L

    Department of Microbiology & Immunology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA.

    Alzheimer's disease (AD) is genetically linked to the processing of amyloid beta protein precursor (AbetaPP). Aside from being the precursor of the amyloid beta (Abeta) found in plaques in the brains of patients with AD, little is known regarding the functional role of AbetaPP. We have recently reported biochemical evidence linking AbetaPP to the JNK signaling cascade by finding that JNK-interacting protein-1 (JIP-1) binds AbetaPP. In order to study the functional implications of this interaction we assayed the carboxyl-terminal of AbetaPP for phosphorylation. We found that the threonine 668 within the AbetaPP intracellular domain (AID or elsewhere AICD) is indeed phosphorylated by JNK1. We surprisingly found that although JIP-1 can facilitate this phosphorylation, it is not required for this process. We also found that JIP-1 only facilitated phosphorylation of AbetaPP but not of the two other family members APLP1 (amyloid precursor-like protein 1) and APLP2. Understanding the connection between AbetaPP phosphorylation and the JNK signaling pathway, which mediates cell response to stress may have important implications in understanding the pathogenesis of Alzheimer's disease.

    Funded by: NIGMS NIH HHS: T32 GM 07288

    The Journal of biological chemistry 2003;278;43;42058-63

  • Amyloid beta protein precursor (AbetaPP), but not AbetaPP-like protein 2, is bridged to the kinesin light chain by the scaffold protein JNK-interacting protein 1.

    Matsuda S, Matsuda Y and D'Adamio L

    Albert Einstein College of Medicine, Department of Microbiology and Immunology, Bronx, New York 10461, USA.

    Proteolytic processing of amyloid beta protein precursor (AbetaPP) generates peptides that regulate normal cell signaling and are implicated in Alzheimer's disease pathogenesis. AbetaPP processing also occurs in nerve processes where AbetaPP is transported from the cell body by kinesin-I, a microtubule motor composed of two kinesin heavy chain and two kinesin light chain (Klc) subunits. AbetaPP transport is supposedly mediated by the direct AbetaPP-Klc1 interaction. Here we demonstrate that the AbetaPP-Klc1 interaction is not direct but is mediated by JNK-interacting protein 1 (JIP1). The phosphotyrosine binding domain of JIP1 binds the cytoplasmic tail of AbetaPP, whereas the JIP1 C-terminal region interacts with the tetratrico-peptide repeats of Klc1. We also show that JIP1 does not bridge the AbetaPP gene family member AbetaPP-like protein 2, APLP2, to Klc1. These results support a model where JIP1 mediates the interaction of AbetaPP to the motor protein kinesin-I and that this JIP1 function is unique for AbetaPP relative to its family member APLP2. Our data suggest that kinesin-I-dependent neuronal AbetaPP transport, which controls AbetaPP processing, may be regulated by JIP1.

    Funded by: NIA NIH HHS: R01 AG22024-01

    The Journal of biological chemistry 2003;278;40;38601-6

  • A peptide inhibitor of c-Jun N-terminal kinase protects against excitotoxicity and cerebral ischemia.

    Borsello T, Clarke PG, Hirt L, Vercelli A, Repici M, Schorderet DF, Bogousslavsky J and Bonny C

    Institut de Biologie Cellulaire et de Morphologie, Université de Lausanne, Rue du Bugnon 9, CH-1005, Switzerland. Tiziana.Borsello@ibcm.unil.ch

    Neuronal death in cerebral ischemia is largely due to excitotoxic mechanisms, which are known to activate the c-Jun N-terminal kinase (JNK) pathway. We have evaluated the neuroprotective power of a cell-penetrating, protease-resistant peptide that blocks the access of JNK to many of its targets. We obtained strong protection in two models of middle cerebral artery occlusion (MCAO): transient occlusion in adult mice and permanent occlusion in 14-d-old rat pups. In the first model, intraventricular administration as late as 6 h after occlusion reduced the lesion volume by more than 90% for at least 14 d and prevented behavioral consequences. In the second model, systemic delivery reduced the lesion by 78% and 49% at 6 and 12 h after ischemia, respectively. Protection correlated with prevention of an increase in c-Jun activation and c-Fos transcription. In view of its potency and long therapeutic window, this protease-resistant peptide is a promising neuroprotective agent for stroke.

    Nature medicine 2003;9;9;1180-6

  • JNK-interacting protein 1 promotes Akt1 activation.

    Kim AH, Sasaki T and Chao MV

    Molecular Neurobiology Program, Skirball Institute for Biomolecular Medicine, Department of Cell Biology, New York University School of Medicine, New York, New York 10016, USA.

    Members of the JNK pathway are organized together by virtue of interactions with JNK interacting protein 1 (JIP1), a scaffold protein. Here we have investigated the possibility that JIP1 may also affect the catalytic activity of Akt1, a serine/threonine kinase that has been implicated in multiple cellular processes, including survival and proliferation. JIP1 expression enhanced Akt1 kinase activity in a dose-dependent manner following serum starvation in 293 cells. Cellular activation of Akt1 following stimulation with low concentrations of insulin-like growth factor (IGF-1) was elevated in the presence of JIP1. JIP1 expression also prolonged Akt1 stimulation after a short IGF-1 pulse. The mechanism of JIP1-mediated Akt1 activation involved JIP1 protein binding to the Akt1 pleckstrin homology domain, which in turn promoted the phosphorylation of the activation T-loop of Akt1 by phosphoinositide-dependent kinase-1. These results suggest that, in certain cellular contexts, JIP1 may act as an Akt1 scaffold, which regulates the enzymatic activity of Akt1. This study also indicates that JIP1 expression can exert signaling effects independent of JNK activity.

    Funded by: NCI NIH HHS: CA56490; NICHD NIH HHS: HD23315; NINDS NIH HHS: NS21072

    The Journal of biological chemistry 2003;278;32;29830-6

  • Recruitment of JNK to JIP1 and JNK-dependent JIP1 phosphorylation regulates JNK module dynamics and activation.

    Nihalani D, Wong HN and Holzman LB

    Division of Nephrology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan 48109-0676, USA.

    JIP1 is a scaffold protein that assembles and facilitates the activation of the mixed lineage kinase-dependent JNK module. Results of earlier work led us to propose a model for JIP1-JNK complex regulation that predicts that under basal conditions, JIP1 maintains DLK in a monomeric, unphosphorylated, and catalytically inactive state. Upon appropriate module stimulation, JNK-JIP1 binding affinity increases and DLK-JIP1 affinity decreases. Dissociation of DLK from JIP1 results in subsequent DLK oligomerization, autophosphorylation, and ultimately module activation. Our previous published results suggested the hypothesis that recruitment of JNK to JIP1 and phosphorylation of JIP1 by JNK is prerequisite for activation of the JNK module (Nihalani, D., Meyer, D., Pajni, S., and Holzman, L. B. (2001) EMBO J. 20, 3447-3458). The present study corroborated this hypothesis by demonstrating that JNK binding to JIP1 is necessary for stimulus-induced dissociation of DLK from JIP1, for DLK oligomerization, and for JNK activation. After mapping JNK-dependent JIP1 phosphorylation sites and testing their functional significance, it was observed that phosphorylation by JNK of JIP1 on Thr-103 and not other phosphorylated JIP1 residues is necessary for the regulation of DLK association with JIP1, DLK activation, and subsequent module activation. A refined model of JIP1-JNK module regulation is presented in which JNK phosphorylation of JIP1 is necessary prior to module activation.

    Funded by: PHS HHS: DO-52788

    The Journal of biological chemistry 2003;278;31;28694-702

  • A scaffold protein JIP-1b enhances amyloid precursor protein phosphorylation by JNK and its association with kinesin light chain 1.

    Inomata H, Nakamura Y, Hayakawa A, Takata H, Suzuki T, Miyazawa K and Kitamura N

    Department of Biological Sciences, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama 226-8501, Japan.

    Amyloid precursor protein (APP) is the precursor molecule of beta-amyloid peptides, the major components of amyloid plaque in patients with Alzheimer's disease. In this study, we isolated JIP-1b, a JNK signaling scaffold protein, as a binding protein of APP, and analyzed the roles of JIP-1b in APP phosphorylation by JNK and the association of kinesin light chain 1 with APP. APP phosphorylation at threonine 668 by JNK was enhanced on the JIP-1b scaffold in vitro and in cultured cells exogenously expressing APP. APP phosphorylation in nerve growth factor-differentiated PC12 cells was mediated by activation of JNK signaling. JIP-1b also enhanced the association of kinesin light chain 1 with APP. Our results suggest that JIP-1b may function as a protein linking the kinesin-I motor protein to the cargo receptor, APP, and that the JNK signaling pathway may regulate the phosphorylation of this cargo protein through the JIP-1b scaffold.

    The Journal of biological chemistry 2003;278;25;22946-55

  • Islet-brain1/C-Jun N-terminal kinase interacting protein-1 (IB1/JIP-1) promoter variant is associated with Alzheimer's disease.

    Helbecque N, Abderrahamani A, Meylan L, Riederer B, Mooser V, Miklossy J, Delplanque J, Boutin P, Nicod P, Haefliger JA, Cottel D, Amouyel P, Froguel P, Waeber G and Abderrhamani A

    Institut National de la Santé et de la Recherche Médicale U508, Pasteur Institute, Lille, France.

    Islet-brain1 (IB1) or c-Jun NH2 terminal kinase interacting protein-1 (JIP-1), the product of the MAPK8IP1 gene, functions as a neuronal scaffold protein to allow signalling specificity. IB1/JIP-1 interacts with many cellular components including the reelin receptor ApoER2, the low-density lipoprotein receptor-related protein (LRP), kinesin and the Alzheimer's amyloid precursor protein. Coexpression of IB1/JIP-1 with other components of the c-Jun NH2 terminal-kinase (JNK) pathway activates the JNK activity; conversely, selective disruption of IB1/JIP-1 in mice reduces the stress-induced apoptosis of neuronal cells. We therefore hypothesized that IB1/JIP-1 is a risk factor for Alzheimer's disease (AD). By immunocytochemistry, we first colocalized the presence of IB1/JIP-1 with JNK and phosphorylated tau in neurofibrillary tangles. We next identified a -499A>G polymorphism in the 5' regulatory region of the MAPK8IP1 gene. In two separate French populations the -499A>G polymorphism of MAPK8IP1 was not associated with an increased risk to AD. However, when stratified on the +766C>T polymorphism of exon 3 of the LRP gene, the IB1/JIP-1 polymorphism was strongly associated with AD in subjects bearing the CC genotype in the LRP gene. The functional consequences of the -499A>G polymorphism of MAPK8IP1 was investigated in vitro. In neuronal cells, the G allele increased transcriptional activity and was associated with an enhanced binding activity. Taken together, these data indicate that the increased transcriptional activity in the presence of the G allele of MAPK8IP1 is a risk factor to the onset of in patients bearing the CC genotype of the LRP gene.

    Funded by: Medical Research Council: G0000477

    Molecular psychiatry 2003;8;4;413-22, 363

  • The JNK-interacting protein-1 scaffold protein targets MAPK phosphatase-7 to dephosphorylate JNK.

    Willoughby EA, Perkins GR, Collins MK and Whitmarsh AJ

    Department of Immunology and Molecular Pathology, University College London and Royal Free Medical School, Windeyer Institute, United Kingdom.

    The c-Jun N-terminal kinase (JNK) group of mitogen-activated protein kinases (MAPKs) are activated by pleiotropic signals including environmental stresses, growth factors, and hormones. A subset of JNK can bind to distinct scaffold proteins that also bind upstream kinases of the JNK pathway, allowing sequential kinase activation within a signaling module. The JNK-interacting protein-1 (JIP-1) scaffold protein specifically binds JNK, MAP kinase kinase 7, and members of the MLK family and is essential for stress-mediated JNK activation in neurones. Here we report that JIP-1 also binds the dual-specificity phosphatases MKP7 and M3/6 via a region independent of its JNK binding domain. The C-terminal region of MKP7, homologous to that of M3/6 but not other DSPs, is required for interaction with JIP-1. When MKP7 is bound to JIP-1 it reduces JNK activation leading to reduced phosphorylation of the JNK target c-Jun. These results indicate that the JIP-1 scaffold protein modulates JNK signaling via association with both protein kinases and protein phosphatases that target JNK.

    The Journal of biological chemistry 2003;278;12;10731-6

  • JNK-interacting protein-1 promotes transcription of A beta protein precursor but not A beta precursor-like proteins, mechanistically different than Fe65.

    Scheinfeld MH, Matsuda S and D'Adamio L

    Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461, USA.

    Processing of the amyloid beta protein precursor (A beta PP) by the beta and gamma secretases leads to the production of two small peptides, amyloid beta and the A beta PP intracellular domain (AID, or called elsewhere AICD). Whereas the role of amyloid beta in the pathogenesis of Alzheimer's disease has been studied extensively, only recently has information begun to accumulate as to the role of AID. Functions identified for AID include its ability to trigger apoptosis and a role in regulating gene transcription, particularly in combination with the A beta PP binding protein Fe65. Here, we report that AID in combination with Janus kinase interacting protein-1 (JIP-1) can activate gene expression. We demonstrate that the mechanism is different from activation in combination with Fe65 by first showing that although Fe65 enters the nucleus in the absence of full-length A beta PP, JIP-1 does not. Additionally, JIP-1-induced activation is Tip60 independent, whereas a complex with AID, Fe65, and Tip60 is formed for Fe65-induced activation. Finally, and probably most interestingly, we show that although the A beta PP family members APLP1 and APLP2 (for amyloid beta precursor-like protein) can cause activation in combination with Fe65, APLP1 and APLP2 show little or no activation in combination with JIP-1. This activity for the AID fragment may help explain the unique functions of A beta PP relative to its other family members, and changes in gene expression found in Alzheimer's disease.

    Funded by: NIGMS NIH HHS: T32 GM007288, T32GM07288

    Proceedings of the National Academy of Sciences of the United States of America 2003;100;4;1729-34

  • Functional interaction of megalin with the megalinbinding protein (MegBP), a novel tetratrico peptide repeat-containing adaptor molecule.

    Petersen HH, Hilpert J, Militz D, Zandler V, Jacobsen C, Roebroek AJ and Willnow TE

    Max-Delbrueck-Center for Molecular Medicine and Medical Faculty of the Free University of Berlin, Germany.

    Megalin is a member of the LDL receptor gene family that plays an important role in forebrain development and in cellular vitamin D metabolism through endocytic uptake of vitamin D metabolites. Similar to other receptors in this gene family, megalin is believed to functionally interact with intracellular proteins through adaptors that bind to the receptor tail and regulate its endocytic and signal transducing activities. Using yeast two-hybrid screens, we identified a novel scaffold protein with tetratrico peptide repeats, the megalin-binding protein (MegBP) that associates with the receptor. The binding site of MegBP was mapped to an N-terminal region on the receptor tail harboring a proline-rich peptide element. MegBP binding did not block the endocytic activity of the receptor; however, overexpression resulted in cellular lethality. In further screens, we identified proteins that bound to MegBP and thus might be recruited to the megalin tail. MegBP-interacting partners included several transcriptional regulators such as the SKI-interacting protein (SKIP), a co-activator of the vitamin D receptor. These finding suggest a model whereby megalin directly participates in transcriptional regulation through controlled sequestration or release of transcription factors via MegBP.

    Journal of cell science 2003;116;Pt 3;453-61

  • Akt1 regulates a JNK scaffold during excitotoxic apoptosis.

    Kim AH, Yano H, Cho H, Meyer D, Monks B, Margolis B, Birnbaum MJ and Chao MV

    Molecular Neurobiology Program, Skirball Institute for Biomolecular Medicine, New York University School of Medicine, New York, NY 10016, USA.

    Cell survival is determined by a balance among signaling cascades, including those that recruit the Akt and JNK pathways. Here we describe a novel interaction between Akt1 and JNK interacting protein 1 (JIP1), a JNK pathway scaffold. Direct association between Akt1 and JIP1 was observed in primary neurons. Neuronal exposure to an excitotoxic stimulus decreased the Akt1-JIP1 interaction and concomitantly increased association between JIP1 and JNK. Akt1 interaction with JIP1 inhibited JIP1-mediated potentiation of JNK activity by decreasing JIP1 binding to specific JNK pathway kinases. Consistent with this view, neurons from Akt1-deficient mice exhibited higher susceptibility to kainate than wild-type littermates. Overexpression of Akt1 mutants that bind JIP1 reduced excitotoxic apoptosis. These results suggest that Akt1 binding to JIP1 acts as a regulatory gate preventing JNK activation, which is released under conditions of excitotoxic injury.

    Funded by: NCI NIH HHS: CA56490; NICHD NIH HHS: HD23315; NINDS NIH HHS: NS21072

    Neuron 2002;35;4;697-709

  • Interaction of Rac exchange factors Tiam1 and Ras-GRF1 with a scaffold for the p38 mitogen-activated protein kinase cascade.

    Buchsbaum RJ, Connolly BA and Feig LA

    Department of Biochemistry, Tufts University School of Medicine and Division of Hematology/Oncology, New England Medical Center, Boston, Massachusetts 02111, USA.

    Tiam1 and Ras-GRF1 are guanine nucleotide exchange factors (GEFs) that activate the Rac GTPase. The two GEFs have similar N-terminal regions containing pleckstrin homology domains followed by coiled-coils and additional sequences that function together to allow regulated GEF activity. Here we show that this N-terminal region of both proteins binds to the scaffold protein IB2/JIP2. IB2/JIP2 is a scaffold for the p38 mitogen-activated protein (MAP) kinase cascade because it binds to the Rac target MLK3, the MAP kinase kinase MKK3, and the p38 MAP kinase. Expression of IB2/JIP2 in cells potentiates the ability of Tiam1 or Ras-GRF1 to activate the p38 MAP kinase cascade but not the Jnk MAP kinase cascade. In addition, Tiam1 or Ras-GRF1 binding to IB2/JIP2 increases the association of the components of the p38 MAP kinase signaling cassette with IB2/JIP2 in cells and activates scaffold-associated p38. These findings imply that Tiam1 and Ras-GRF1 can contribute to Rac signaling specificity by their ability to form a complex with a scaffold that binds components of one of the many known Rac effector pathways.

    Molecular and cellular biology 2002;22;12;4073-85

  • Interaction of Alzheimer's beta -amyloid precursor family proteins with scaffold proteins of the JNK signaling cascade.

    Taru H, Iijima K, Hase M, Kirino Y, Yagi Y and Suzuki T

    Laboratory of Neurobiophysics, School of Pharmaceutical Sciences, the University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan.

    We have isolated a novel protein based on its association with Drosophila APP-like protein (APPL), a homolog of the beta-amyloid precursor protein (APP) that is implicated in Alzheimer's disease. This novel APPL-interacting protein 1 (APLIP1) contains a Src homology 3 domain and a phosphotyrosine interaction domain and is expressed abundantly in neural tissues. The phosphotyrosine interaction domain of APLIP1 interacts with a sequence containing GYENPTY in the cytoplasmic domain of APPL. APLIP1 is highly homologous to the carboxyl-terminal halves of mammalian c-Jun NH(2)-terminal kinase (JNK)-interacting protein 1b (JIP1b) and 2 (JIP2), which also contain Src homology 3 and phosphotyrosine interaction domains. The similarity of APLIP1 to JIP1b and JIP2 includes interaction with component(s) of the JNK signaling pathway and with the motor protein kinesin and the formation of homo-oligomers. JIP1b interacts strongly with the cytoplasmic domain of APP (APPcyt), as APLIP1 does with APPL, but the interaction of JIP2 with APPcyt is weak. Overexpression of JIP1b slightly enhances the JNK-dependent threonine phosphorylation of APP in cultured cells, but that of JIP2 suppresses it. These observations suggest that the interactions of APP family proteins with APLIP1, JIP1b, and JIP2 are conserved and play important roles in the metabolism and/or the function of APPs including the regulation of APP phosphorylation by JNK. Analysis of APP family proteins and their associated proteins is expected to contribute to understanding the molecular process of neural degeneration in Alzheimer's disease.

    The Journal of biological chemistry 2002;277;22;20070-8

  • Complementation of a p300/CBP defective-binding mutant of adenovirus E1a by human papillomavirus E6 proteins.

    Bernat A, Massimi P and Banks L

    International Centre for Genetic Engineering and Biotechnology, Padriciano 99, I-34012 Trieste, Italy1.

    Previous studies have shown that the human papillomavirus type 16 (HPV-16) E6 protein binds to p300/CBP and abrogates its transcriptional co-activator function. However, there is little information on the biological consequences of this interaction and discrepancy as to whether the interaction is high-risk E6 specific or not. We performed a series of studies to compare the interactions of HPV-18 and HPV-11 E6 with p300, and showed that both high- and low- risk E6 proteins bind p300. In addition, using a transformation-deficient mutant of adenovirus E1a, which cannot interact with p300, we demonstrated that HPV-16, HPV-18 and, to a lesser extent, HPV-11 E6, can complement this mutant in cell transformation assays. In contrast, a mutant of HPV-16 E6 which does not bind p300 failed to rescue the E1a mutant. These results suggest that the E6-p300 interaction may be important for the ability of HPV E6 to contribute towards cell transformation.

    The Journal of general virology 2002;83;Pt 4;829-833

  • alpha-Synuclein protects against oxidative stress via inactivation of the c-Jun N-terminal kinase stress-signaling pathway in neuronal cells.

    Hashimoto M, Hsu LJ, Rockenstein E, Takenouchi T, Mallory M and Masliah E

    Department of Neurosciences, University of California San Diego, School of Medicine, La Jolla, California 92093-0624, USA.

    The expression of alpha-synuclein, a synaptic molecule implicated in the pathogenesis of neurodegenerative disorders such as Parkinson's disease and Lewy body disease is increased upon injury to the nervous system, indicating that it might play a role in regeneration and plasticity; however, the mechanisms are unclear. Because c-Jun N-terminal kinase (JNK), a member of the mitogen-activated protein kinase family, plays an important role in stress response, the main objective of the present study was to better understand the involvement of this pathway in the signaling responses associated with resistance to injury in cells expressing alpha-synuclein. For this purpose, the JNK-signaling pathway was investigated in alpha-synuclein-transfected neuronal cell line glucose transporter (GT) 1-7 under oxidative stress conditions. Although hydrogen peroxide challenge resulted in JNK activation and cell death in cells transfected with vector control or beta-synuclein, alpha-synuclein-transfected cells were resistant to hydrogen peroxide, and JNK was not activated. The inactivation of JNK in the alpha-synuclein-transfected cells was associated with increased expression and activity of JNK-interacting protein (JIP)-1b/islet-brain (IB)1, the scaffold protein for the JNK pathway. Similarly, cells transfected with JIP-1b/IB1 were resistant to hydrogen peroxide associated with inactivation of the JNK pathway. In these cells, expression of endogenous alpha-synuclein was significantly increased at the protein level. Furthermore, alpha-synuclein was co-localized with JIP-1b/IB1 in the growth cones. Taken together, these results suggest that increased alpha-synuclein expression might protect cells from oxidative stress by inactivation of JNK via increased expression of JIP-1b/IB1. Furthermore, interactions between alpha-synuclein and JIP-1b/IB1 may play a mutual role in the neuronal response to injury and neurodegeneration.

    Funded by: NIA NIH HHS: AG10689, AG18440, AG5131

    The Journal of biological chemistry 2002;277;13;11465-72

  • Jun NH2-terminal kinase (JNK) interacting protein 1 (JIP1) binds the cytoplasmic domain of the Alzheimer's beta-amyloid precursor protein (APP).

    Scheinfeld MH, Roncarati R, Vito P, Lopez PA, Abdallah M and D'Adamio L

    Albert Einstein College of Medicine, Department of Microbiology & Immunology, Bronx, New York 10461, USA.

    The familial Alzheimer's disease gene product amyloid beta precursor protein (APP) is sequentially processed by beta- and gamma-secretases to generate the Abeta peptide. The biochemical pathway leading to Abeta formation has been extensively studied since extracellular aggregates of Abeta peptides are considered the culprit of Alzheimer's disease. Aside from its pathological relevance, the biological role of APP processing is unknown. Cleavage of APP by gamma-secretase releases, together with Abeta, a COOH-terminal APP intracellular domain, termed AID. This peptide has recently been identified in brain tissue of normal control and patients with sporadic Alzheimer's disease. We have previously shown that AID acts as a positive regulator of apoptosis. Nevertheless, the molecular mechanism by which AID regulates this process remains unknown. Hoping to gain clues about the function of APP, we used the yeast two-hybrid system to identify interaction between the AID region of APP and JNK-interacting protein-1 (JIP1). This molecular interaction is confirmed in vitro, in vivo by fluorescence resonance energy transfer (FRET), and in mouse brain lysates. These data provide a link between APP and its processing by gamma-secretase, and stress kinase signaling pathways. These pathways are known regulators of apoptosis and may be involved in the pathogenesis of Alzheimer's disease.

    Funded by: NIGMS NIH HHS: T32GM07288

    The Journal of biological chemistry 2002;277;5;3767-75

  • Phosphorylation of Pax2 by the c-Jun N-terminal kinase and enhanced Pax2-dependent transcription activation.

    Cai Y, Lechner MS, Nihalani D, Prindle MJ, Holzman LB and Dressler GR

    Departments of Pathology and Medicine, University of Michigan, Ann Arbor, Michigan 48109, USA.

    The Pax gene family encodes DNA-binding proteins that can both activate and repress transcription of specific target genes during embryonic development. Pax proteins are required for pattern formation and cell differentiation in a broad spectrum of developing tissues. Consistent with its expression in the intermediate mesoderm, the optic cup and stalk, and the otic vesicle, Pax2, a member of the Pax2/5/8 subfamily, is essential for the development of the renal epithelia, the optic cup, and the inner ear. In addition to a DNA binding domain, the Pax2 protein contains a carboxyl-terminal transactivation domain rich in serine, threonine, and tyrosine. In this report, we demonstrate that the Pax2 transactivation domain is phosphorylated by the c-Jun N-terminal kinase, but not the ERK1/2 or p38 MAP kinases and that phosphorylation is coincident with increased transactivation of a Pax2-dependent reporter gene. Activation of JNK by either upstream kinase MEKK1 or DLK or by expression of Wnt signaling proteins significantly enhances Pax2 phosphorylation in cells. In vitro kinase assays using immunoprecipitated JNK or constitutively active, recombinant JNK show phosphorylation of GST-Pax2 fusion proteins. In transfected cells, phosphorylation of Pax2 correlates with increased transactivation of a Pax2-dependent reporter gene, suggesting that serine/threonine phosphorylation of the transactivation domain is important for Pax2 activity. Pax2 can form a complex with the JNK scaffolding protein JIP1, and this interaction is enhanced by activation of the JNK signaling module with the upstream kinase DLK. The data demonstrate that Pax2 is a new target for the JNK signaling module and point to a novel mechanism for mediating Pax-dependent transcription regulation.

    Funded by: NIDDK NIH HHS: DK54723, DK54740

    The Journal of biological chemistry 2002;277;2;1217-22

  • Mixed lineage kinase LZK forms a functional signaling complex with JIP-1, a scaffold protein of the c-Jun NH(2)-terminal kinase pathway.

    Ikeda A, Hasegawa K, Masaki M, Moriguchi T, Nishida E, Kozutsumi Y, Oka S and Kawasaki T

    Department of Biological Chemistry and CREST (Core Research for Educational Science and Technology) Project, Japan Science and Technology Corporation, Kyoto 606-8501, Japan.

    Leucine zipper-bearing kinase (LZK) is a novel member of the mixed lineage kinase (MLK) protein family, the cDNA of which was first cloned from a human brain cDNA library [Sakuma, H., Ikeda, A., Oka, S., Kozutsumi, Y., Zanetta, J.-P., and Kawasaki, T. (1997) J. Biol. Chem. 272, 28622-28629]. Several MLK family proteins have been proposed to function as MAP kinase kinase kinases in the c-Jun NH(2) terminal kinase (JNK)/stress-activated protein kinase (SAPK) pathway. In the present study, we demonstrated that, like other MLKs, LZK activated the JNK/SAPK pathway but not the ERK pathway. LZK directly phosphorylated and activated MKK7, one of the two MAPKKs in the JNK/SAPK pathway, to a comparable extent to a constitutive active form of MEKK1 (MEKK1DeltaN), suggesting a biological role of LZK as a MAPKKK in the JNK/SAPK pathway. Recent studies have revealed the essential roles of scaffold proteins in intracellular signaling pathways including MAP kinase pathways. JIP-1, one of the scaffold proteins, has been shown to be associated with MLKs, MKK7, and JNK [Whitmarsh, A.J., Cavanagh, J., Tournier, C., Yasuda, J., and Davis, R.J. (1998) Science 281, 1671-1674], suggesting the presence of a selective signaling pathway including LZK, MKK7, and JNK. Consistent with this hypothesis, we provided evidence that LZK is associated with the C-terminal region of JIP-1 through its kinase catalytic domain. In addition, LZK-induced JNK activation was markedly enhanced when LZK and JNK were co-expressed with JIP-1. These results constituted important clues for understanding the molecular mechanisms regulating the signaling specificities of various JNK activators under different cellular conditions.

    Journal of biochemistry 2001;130;6;773-81

  • The transcriptional repressor REST determines the cell-specific expression of the human MAPK8IP1 gene encoding IB1 (JIP-1).

    Abderrahmani A, Steinmann M, Plaisance V, Niederhauser G, Haefliger JA, Mooser V, Bonny C, Nicod P and Waeber G

    Department of Internal Medicine, CHUV-University Hospital, Lausanne, Switzerland.

    Islet-brain 1 (IB1) is the human and rat homologue of JIP-1, a scaffold protein interacting with the c-Jun amino-terminal kinase (JNK). IB1 expression is mostly restricted to the endocrine pancreas and to the central nervous system. Herein, we explored the transcriptional mechanism responsible for this preferential islet and neuronal expression of IB1. A 731-bp fragment of the 5' regulatory region of the human MAPK8IP1 gene was isolated from a human BAC library and cloned upstream of a luciferase reporter gene. This construct drove high transcriptional activity in both insulin-secreting and neuron-like cells but not in unrelated cell lines. Sequence analysis of this promoter region revealed the presence of a neuron-restrictive silencer element (NRSE) known to bind repressor zinc finger protein REST. This factor is not expressed in insulin-secreting and neuron-like cells. By mobility shift assay, we confirmed that REST binds to the NRSE present in the IB1 promoter. Once transiently transfected in beta-cell lines, the expression vector encoding REST repressed IB1 transcriptional activity. The introduction of a mutated NRSE in the 5' regulating region of the IB1 gene abolished the repression activity driven by REST in insulin-secreting beta cells and relieved the low transcriptional activity of IB1 observed in unrelated cells. Moreover, transfection in non-beta and nonneuronal cell lines of an expression vector encoding REST lacking its transcriptional repression domain relieved IB1 promoter activity. Last, the REST-mediated repression of IB1 could be abolished by trichostatin A, indicating that deacetylase activity is required to allow REST repression. Taken together, these data establish a critical role for REST in the control of the tissue-specific expression of the human IB1 gene.

    Molecular and cellular biology 2001;21;21;7256-67

  • c-Jun N-terminal kinase (JNK)-interacting protein-1b/islet-brain-1 scaffolds Alzheimer's amyloid precursor protein with JNK.

    Matsuda S, Yasukawa T, Homma Y, Ito Y, Niikura T, Hiraki T, Hirai S, Ohno S, Kita Y, Kawasumi M, Kouyama K, Yamamoto T, Kyriakis JM and Nishimoto I

    Department of Pharmacology and Neurosciences, KEIO University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan.

    Using a yeast two-hybrid method, we searched for amyloid precursor protein (APP)-interacting molecules by screening mouse and human brain libraries. In addition to known interacting proteins containing a phosphotyrosine-interaction-domain (PID)-Fe65, Fe65L, Fe65L2, X11, and mDab1, we identified, as a novel APP-interacting molecule, a PID-containing isoform of mouse JNK-interacting protein-1 (JIP-1b) and its human homolog IB1, the established scaffold proteins for JNK. The APP amino acids Tyr(682), Asn(684), and Tyr(687) in the G(681)YENPTY(687) region were all essential for APP/JIP-1b interaction, but neither Tyr(653) nor Thr(668) was necessary. APP-interacting ability was specific for this additional isoform containing PID and was shared by both human and mouse homologs. JIP-1b expressed by mammalian cells was efficiently precipitated by the cytoplasmic domain of APP in the extreme Gly(681)-Asn(695) domain-dependent manner. Reciprocally, both full-length wild-type and familial Alzheimer's disease mutant APPs were precipitated by PID-containing JIP constructs. Antibodies raised against the N and C termini of JIP-1b coprecipitated JIP-1b and wild-type or mutant APP in non-neuronal and neuronal cells. Moreover, human JNK1beta1 formed a complex with APP in a JIP-1b-dependent manner. Confocal microscopic examination demonstrated that APP and JIP-1b share similar subcellular localization in transfected cells. These data indicate that JIP-1b/IB1 scaffolds APP with JNK, providing a novel insight into the role of the JNK scaffold protein as an interface of APP with intracellular functional molecules.

    The Journal of neuroscience : the official journal of the Society for Neuroscience 2001;21;17;6597-607

  • Cargo of kinesin identified as JIP scaffolding proteins and associated signaling molecules.

    Verhey KJ, Meyer D, Deehan R, Blenis J, Schnapp BJ, Rapoport TA and Margolis B

    Howard Hughes Medical Institute, Harvard Medical School, Boston, Massachusetts 02115, USA. kverhey@hms.harvard.edu

    The cargo that the molecular motor kinesin moves along microtubules has been elusive. We searched for binding partners of the COOH terminus of kinesin light chain, which contains tetratricopeptide repeat (TPR) motifs. Three proteins were found, the c-jun NH(2)-terminal kinase (JNK)-interacting proteins (JIPs) JIP-1, JIP-2, and JIP-3, which are scaffolding proteins for the JNK signaling pathway. Concentration of JIPs in nerve terminals requires kinesin, as evident from the analysis of JIP COOH-terminal mutants and dominant negative kinesin constructs. Coprecipitation experiments suggest that kinesin carries the JIP scaffolds preloaded with cytoplasmic (dual leucine zipper-bearing kinase) and transmembrane signaling molecules (the Reelin receptor, ApoER2). These results demonstrate a direct interaction between conventional kinesin and a cargo, indicate that motor proteins are linked to their membranous cargo via scaffolding proteins, and support a role for motor proteins in spatial regulation of signal transduction pathways.

    The Journal of cell biology 2001;152;5;959-70

  • Cell-permeable peptide inhibitors of JNK: novel blockers of beta-cell death.

    Bonny C, Oberson A, Negri S, Sauser C and Schorderet DF

    Division of Medical Genetics, Centre Hospitalier Universitaire Vaudois-University Hospital, Lausanne, Switzerland. christophe.bonny@chuv.hospvd.ch

    Stress conditions and proinflammatory cytokines activate the c-Jun NH2-terminal kinase (JNK), a member of the stress-activated group of mitogen-activated protein kinases (MAPKs). We recently demonstrated that inhibition of JNK signaling with the use of the islet-brain (IB) 1 and 2 proteins prevented interleukin (IL)-1beta-induced pancreatic beta-cell death. Bioactive cell-permeable peptide inhibitors of JNK were engineered by linking the minimal 20-amino acid inhibitory domains of the IB proteins to the 10-amino acid HIV-TAT sequence that rapidly translocates inside cells. Kinase assays indicate that the inhibitors block activation of the transcription factor c-Jun by JNK. Addition of the peptides to the insulin-secreting betaTC-3 cell line results in a marked inhibition of IL-1beta-induced c-jun and c-fos expression. The peptides protect betaTC-3 cells against apoptosis induced by IL-1beta. All-D retro-inverso peptides penetrate cells as efficiently as the L-enantiomers, decrease c-Jun activation by JNK, and remain highly stable inside cells. These latter peptides confer full protection against IL-1beta-induced apoptosis for up to 2 weeks of continual treatment with IL-1beta. These data establish these bioactive cell-permeable peptides as potent pharmacological compounds that decrease intracellular JNK signaling and confer long-term protection to pancreatic beta-cells from IL-1beta-induced apoptosis.

    Diabetes 2001;50;1;77-82

  • Connexin26 is regulated in rat urothelium by the scaffold protein IB1/JIP-1.

    Tawadros T, Meda P, Leisinger HJ, Waeber G and Haefliger JA

    Service of Urology, University Hospital, Lausanne, Switzerland.

    Proper function of the wall of bladder requires gap junctional communication for coordinating the responses of smooth muscle (SMC) and urothelial cells exposed to urine pressure. In the rat bladder, Cx43 is expressed by SMC and urothelial cells, whereas Cx26 expression is restricted to the epithelium. We used a model of bladder outlet obstruction, in which a ligature is placed around the urethra to increase voiding pressure. Increased fluid pressure was associated with increased Cx43 and Cx26 mRNA expression and with the activation of a signaling cascade including the transcription factor c-Jun, which is a component of the AP-1 complex. The signaling pathway of the c-Jun NH2 terminal kinase (JNK) requires the presence of the scaffold protein Islet-Brain1/c-Jun amino-terminal kinase Interacting Protein-1 (IB1/JIP-1). Under stress conditions resulting from urine retention, we have found a reduced content of IB1/JIP-1 in urothelial cells, which in turn induced a drastic increase of JNK and AP-1 binding activities. The stress-induced activation of JNK was prevented by overexpressing IB1/JIP-1, using a viral gene transfer approach, a condition which also resulted in a decrease in Cx26 mRNA. The data show that: 1) mechanical stress of urothelial cells activates in vivo JNK, as a consequence of a regulated expression of IB1/JIP-1 and 2) that urothelial Cx26 may be directly regulated by the AP-1 complex.

    Cell communication & adhesion 2001;8;4-6;303-6

  • Interactions of the low density lipoprotein receptor gene family with cytosolic adaptor and scaffold proteins suggest diverse biological functions in cellular communication and signal transduction.

    Gotthardt M, Trommsdorff M, Nevitt MF, Shelton J, Richardson JA, Stockinger W, Nimpf J and Herz J

    Department of Molecular Genetics and Pathology, University of Texas Southwestern Medical Center, Dallas 75390-9046, USA.

    The members of the low density lipoprotein (LDL) receptor gene family bind a broad spectrum of extracellular ligands. Traditionally, they had been regarded as mere cargo receptors that promote the endocytosis and lysosomal delivery of these ligands. However, recent genetic experiments in mice have revealed critical functions for two LDL receptor family members, the very low density lipoprotein receptor and the apoE receptor-2, in the transmission of extracellular signals and the activation of intracellular tyrosine kinases. This process regulates neuronal migration and is crucial for brain development. Signaling through these receptors requires the interaction of their cytoplasmic tails with the intracellular adaptor protein Disabled-1 (DAB1). Here, we identify an extended set of cytoplasmic proteins that might also participate in signal transmission by the LDL receptor gene family. Most of these novel proteins are adaptor or scaffold proteins that contain PID or PDZ domains and function in the regulation of mitogen-activated protein kinases, cell adhesion, vesicle trafficking, or neurotransmission. We show that binding of DAB1 interferes with receptor internalization suggesting a mechanism by which signaling through this class of receptors might be regulated. Taken together, these findings imply much broader physiological functions for the LDL receptor family than had previously been appreciated. They form the basis for the elucidation of the molecular pathways by which cells respond to the diversity of ligands that bind to these multifunctional receptors on the cell surface.

    Funded by: NHLBI NIH HHS: HL20948, HL63762, R37 HL063762

    The Journal of biological chemistry 2000;275;33;25616-24

  • IB1 reduces cytokine-induced apoptosis of insulin-secreting cells.

    Bonny C, Oberson A, Steinmann M, Schorderet DF, Nicod P and Waeber G

    Division of Medical Genetics and the Department of Internal Medicine, CHUV University Hospital, 1011 Lausanne Switzerland. christophe.bonny@chuv.hospvd.ch

    IB1/JIP-1 is a scaffold protein that interacts with upstream components of the c-Jun N-terminal kinase (JNK) signaling pathway. IB1 is expressed at high levels in pancreatic beta cells and may therefore exert a tight control on signaling events mediated by JNK in these cells. Activation of JNK by interleukin 1 (IL-1beta) or by the upstream JNK constitutive activator DeltaMEKK1 promoted apoptosis in two pancreatic beta cell lines and decreased IB1 content by 50-60%. To study the functional consequences of the reduced IB1 content in beta cell lines, we used an insulin-secreting cell line expressing an inducible IB1 antisense RNA that lead to a 38% IB1 decrease. Reducing IB1 levels in these cells increased phosphorylation of c-Jun and increased the apoptotic rate in presence of IL-1beta. Nitric oxide production was not stimulated by expression of the IB1 antisense RNA. Complementary experiments indicated that overexpression of IB1 in insulin-producing cells prevented JNK-mediated activation of the transcription factors c-Jun, ATF2, and Elk1 and decreased IL-1beta- and DeltaMEKK1-induced apoptosis. These data indicate that IB1 plays an anti-apoptotic function in insulin-producing cells probably by controlling the activity of the JNK signaling pathway.

    The Journal of biological chemistry 2000;275;22;16466-72

  • The gene MAPK8IP1, encoding islet-brain-1, is a candidate for type 2 diabetes.

    Waeber G, Delplanque J, Bonny C, Mooser V, Steinmann M, Widmann C, Maillard A, Miklossy J, Dina C, Hani EH, Vionnet N, Nicod P, Boutin P and Froguel P

    Department of Internal Medicine, CHUV-University Hospital, Lausanne, Switzerland. gwaeber@chuv.hospvd.ch

    Type 2 diabetes is a polygenic and genetically heterogeneous disease . The age of onset of the disease is usually late and environmental factors may be required to induce the complete diabetic phenotype. Susceptibility genes for diabetes have not yet been identified. Islet-brain-1 (IB1, encoded by MAPK8IP1), a novel DNA-binding transactivator of the glucose transporter GLUT2 (encoded by SLC2A2), is the homologue of the c-Jun amino-terminal kinase-interacting protein-1 (JIP-1; refs 2-5). We evaluated the role of IBi in beta-cells by expression of a MAPK8IP1 antisense RNA in a stable insulinoma beta-cell line. A 38% decrease in IB1 protein content resulted in a 49% and a 41% reduction in SLC2A2 and INS (encoding insulin) mRNA expression, respectively. In addition, we detected MAPK8IP1 transcripts and IBi protein in human pancreatic islets. These data establish MAPK8IP1 as a candidate gene for human diabetes. Sibpair analyses performed on i49 multiplex French families with type 2 diabetes excluded MAPK8IP1 as a major diabetogenic locus. We did, however, identify in one family a missense mutation located in the coding region of MAPK8IP1 (559N) that segregated with diabetes. In vitro, this mutation was associated with an inability of IB1 to prevent apoptosis induced by MAPK/ERK kinase kinase 1 (MEKK1) and a reduced ability to counteract the inhibitory action of the activated c-JUN amino-terminal kinase (JNK) pathway on INS transcriptional activity. Identification of this novel non-maturity onset diabetes of the young (MODY) form of diabetes demonstrates that IB1 is a key regulator of 3-cell function.

    Nature genetics 2000;24;3;291-5

  • Interaction of a mitogen-activated protein kinase signaling module with the neuronal protein JIP3.

    Kelkar N, Gupta S, Dickens M and Davis RJ

    Howard Hughes Medical Institute, Program in Molecular Medicine, Department of Biochemistry, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA.

    The c-Jun NH(2)-terminal kinase (JNK) group of mitogen-activated protein kinases (MAPKs) is activated in response to the treatment of cells with inflammatory cytokines and by exposure to environmental stress. JNK activation is mediated by a protein kinase cascade composed of a MAPK kinase and a MAPK kinase kinase. Here we describe the molecular cloning of a putative molecular scaffold protein, JIP3, that binds the protein kinase components of a JNK signaling module and facilitates JNK activation in cultured cells. JIP3 is expressed in the brain and at lower levels in the heart and other tissues. Immunofluorescence analysis demonstrated that JIP3 was present in the cytoplasm and accumulated in the growth cones of developing neurites. JIP3 is a member of a novel class of putative MAPK scaffold proteins that may regulate signal transduction by the JNK pathway.

    Molecular and cellular biology 2000;20;3;1030-43

  • Interaction of c-Jun amino-terminal kinase interacting protein-1 with p190 rhoGEF and its localization in differentiated neurons.

    Meyer D, Liu A and Margolis B

    Howard Hughes Medical Institute, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA.

    c-Jun amino-terminal kinase (JNK) interacting protein-1 (JIP-1) was originally identified as a cytoplasmic inhibitor of JNK. More recently, JIP-1 was proposed to function as a scaffold protein by complexing specific components of the JNK signaling pathway, namely JNK, mitogen-activated protein kinase kinase 7, and mixed lineage kinase 3. We have identified the human homologue of JIP-1 that contains a phosphotyrosine binding (PTB) domain in addition to a JNK binding domain and an Src homology 3 domain. To identify binding targets for the hJIP-1 PTB domain, a mouse embryo cDNA library was screened using the yeast two-hybrid system. One clone encoded a 191-amino acid region of the neuronal protein rhoGEF, an exchange factor for rhoA. Overexpression of rhoGEF promotes cytoskeletal rearrangement and cell rounding in NIE-115 neuronal cells. The interaction of JIP-1 with rhoGEF was confirmed by coimmunoprecipitation of these proteins from lysates of transiently transfected HEK 293 cells. Using glutathione S-transferase rhoGEF fusion proteins containing deletion or point mutations, we identified a putative PTB binding site within rhoGEF. This binding site does not contain tyrosine, indicating that the JIP PTB domain, like that of Xll alpha and Numb, binds independently of phosphotyrosine. Several forms of endogenous JIP-1 protein can be detected in neuronal cell lines. Indirect immunofluorescence analysis localized endogenous JIP-1 to the tip of the neurites in differentiated NIE-115 and PC12 cells. The interaction of JIP-1 with rhoGEF and its subcellular localization suggests that JIP-1 may function to specifically localize a signaling complex in neuronal cells.

    The Journal of biological chemistry 1999;274;49;35113-8

  • The JIP group of mitogen-activated protein kinase scaffold proteins.

    Yasuda J, Whitmarsh AJ, Cavanagh J, Sharma M and Davis RJ

    Howard Hughes Medical Institute, Program in Molecular Medicine, Department of Biochemistry and Molecular Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA.

    Activation of the c-Jun NH(2)-terminal kinase (JNK) group of mitogen-activated protein (MAP) kinases is mediated by a protein kinase cascade. This signaling mechanism may be coordinated by the interaction of components of the protein kinase cascade with scaffold proteins. The JNK-interacting protein (JIP) group of scaffold proteins selectively mediates signaling by the mixed-lineage kinase (MLK)-->MAP kinase kinase 7 (MKK7)-->JNK pathway. The scaffold proteins JIP1 and JIP2 interact to form oligomeric complexes that accumulate in peripheral cytoplasmic projections extended at the cell surface. The JIP proteins function by aggregating components of a MAP kinase module (including MLK, MKK7, and JNK) and facilitate signal transmission by the protein kinase cascade.

    Molecular and cellular biology 1999;19;10;7245-54

  • Genomic organization, fine-mapping, and expression of the human islet-brain 1 (IB1)/c-Jun-amino-terminal kinase interacting protein-1 (JIP-1) gene.

    Mooser V, Maillard A, Bonny C, Steinmann M, Shaw P, Yarnall DP, Burns DK, Schorderet DF, Nicod P and Waeber G

    Department of Pathology, CHUV University Hospital, Lausanne, CH-1011, Switzerland. vincent.mooser@hola.hospvd.ch

    Islet-brain 1 (IB1), a regulator of the pancreatic beta-cell function in the rat, is homologous to JIP-1, a murine inhibitor of c-Jun amino-terminal kinase (JNK). Whether IB1 and JIP-1 are present in humans was not known. We report the sequence of the 2133-bp human IB1 cDNA, the expression, structure, and fine-mapping of the human IB1 gene, and the characterization of an IB1 pseudogene. Human IB1 is 94% identical to rat IB1. The tissue-specific expression of IB1 in human is similar to that observed in rodent. The IB1 gene contains 12 exons and maps to chromosome 11 (11p11.2-p12), a region that is deleted in DEFECT-11 syndrome. Apart from an IB1 pseudogene on chromosome 17 (17q21), no additional IB1-related gene was found in the human genome. Our data indicate that the sequence and expression pattern of IB1 are highly conserved between rodent and human and provide the necessary tools to investigate whether IB1 is involved in human diseases.

    Genomics 1999;55;2;202-8

  • A mammalian scaffold complex that selectively mediates MAP kinase activation.

    Whitmarsh AJ, Cavanagh J, Tournier C, Yasuda J and Davis RJ

    Program in Molecular Medicine, Department of Biochemistry and Molecular Biology, University of Massachusetts Medical School and Howard Hughes Medical Institute, Worcester, MA 01605, USA.

    The c-Jun NH2-terminal kinase (JNK) group of mitogen-activated protein (MAP) kinases is activated by the exposure of cells to multiple forms of stress. A putative scaffold protein was identified that interacts with multiple components of the JNK signaling pathway, including the mixed-lineage group of MAP kinase kinase kinases (MLK), the MAP kinase kinase MKK7, and the MAP kinase JNK. This scaffold protein selectively enhanced JNK activation by the MLK signaling pathway. These data establish that a mammalian scaffold protein can mediate activation of a MAP kinase signaling pathway.

    Science (New York, N.Y.) 1998;281;5383;1671-4

  • IB1, a JIP-1-related nuclear protein present in insulin-secreting cells.

    Bonny C, Nicod P and Waeber G

    Department of Internal Medicine B, University Hospital, Lausanne, Switzerland.

    JIP-1 is a cytoplasmic inhibitor of the c-Jun amino-terminal kinase activated pathway recently cloned from a mouse brain cDNA library. We report herein the expression cloning of a rat cDNA encoding a JIP-1-related nuclear protein from a pancreatic beta-cell cDNA library that we named IB1 for Islet-Brain 1. IB1 was isolated by its ability to bind to GTII, a cis-regulatory element of the GLUT2 promoter. The IB1 cDNA encodes a 714-amino acid protein, which differs from JIP-1 by the insertion of 47 amino acids in the carboxyl-terminal part of the protein. The remaining 667 amino acids are 97% identical to JIP-1. The 47-amino acid insertion contains a truncated phosphotyrosine interaction domain and a putative helix-loop-helix motif. Recombinant IB1 (amino acids 1-714 and 280-714) was shown to bind in vitro to GTII. Functionally IB1 transactivated the GLUT2 gene. IB1 was localized within the cytoplasm and the nucleus of insulin-secreting cells or COS-7 cells transfected with an expression vector encoding IB1. Using a heterologous GAL4 system, we localized an activation domain of IB1 within the first 280 amino acids of the protein. These data demonstrate that IB1 is a DNA-binding protein related to JIP-1, which is highly expressed in pancreatic beta-cells where it functions as a transactivator of the GLUT2 gene.

    The Journal of biological chemistry 1998;273;4;1843-6

  • A cytoplasmic inhibitor of the JNK signal transduction pathway.

    Dickens M, Rogers JS, Cavanagh J, Raitano A, Xia Z, Halpern JR, Greenberg ME, Sawyers CL and Davis RJ

    Howard Hughes Medical Institute and Program in Molecular Medicine, Department of Biochemistry and Molecular Biology, University of Massachusetts Medical School, 373 Plantation Street, Worcester, MA 01605, USA.

    The c-Jun amino-terminal kinase (JNK) is a member of the stress-activated group of mitogen-activated protein (MAP) kinases that are implicated in the control of cell growth. A murine cytoplasmic protein that binds specifically to JNK [the JNK interacting protein-1 (JIP-1)] was characterized and cloned. JIP-1 caused cytoplasmic retention of JNK and inhibition of JNK-regulated gene expression. In addition, JIP-1 suppressed the effects of the JNK signaling pathway on cellular proliferation, including transformation by the Bcr-Abl oncogene. This analysis identifies JIP-1 as a specific inhibitor of the JNK signal transduction pathway and establishes protein targeting as a mechanism that regulates signaling by stress-activated MAP kinases.

    Funded by: NCI NIH HHS: CA43855, CA65861

    Science (New York, N.Y.) 1997;277;5326;693-6

  • Large-scale concatenation cDNA sequencing.

    Yu W, Andersson B, Worley KC, Muzny DM, Ding Y, Liu W, Ricafrente JY, Wentland MA, Lennon G and Gibbs RA

    A total of 100 kb of DNA derived from 69 individual human brain cDNA clones of 0.7-2.0 kb were sequenced by concatenated cDNA sequencing (CCS), whereby multiple individual DNA fragments are sequenced simultaneously in a single shotgun library. The method yielded accurate sequences and a similar efficiency compared with other shotgun libraries constructed from single DNA fragments (> 20 kb). Computer analyses were carried out on 65 cDNA clone sequences and their corresponding end sequences to examine both nucleic acid and amino acid sequence similarities in the databases. Thirty-seven clones revealed no DNA database matches, 12 clones generated exact matches (> or = 98% identity), and 16 clones generated nonexact matches (57%-97% identity) to either known human or other species genes. Of those 28 matched clones, 8 had corresponding end sequences that failed to identify similarities. In a protein similarity search, 27 clone sequences displayed significant matches, whereas only 20 of the end sequences had matches to known protein sequences. Our data indicate that full-length cDNA insert sequences provide significantly more nucleic acid and protein sequence similarity matches than expressed sequence tags (ESTs) for database searching.

    Funded by: NHGRI NIH HHS: 1F32 HG00169-01, P30 HG00210-05, R01 HG00823

    Genome research 1997;7;4;353-8

  • A "double adaptor" method for improved shotgun library construction.

    Andersson B, Wentland MA, Ricafrente JY, Liu W and Gibbs RA

    Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, Texas, 77030, USA.

    The efficiency of shotgun DNA sequencing depends to a great extent on the quality of the random-subclone libraries used. We here describe a novel "double adaptor" strategy for efficient construction of high-quality shotgun libraries. In this method, randomly sheared and end-repaired fragments are ligated to oligonucleotide adaptors creating 12-base overhangs. Nonphosphorylated oligonucleotides are used, which prevents formation of adaptor dimers and ensures efficient ligation of insert to adaptor. The vector is prepared from a modified M13 vector, by KpnI/PstI digestion followed by ligation to oligonucleotides with ends complementary to the overhangs created in the digest. These adaptors create 5'-overhangs complementary to those on the inserts. Following annealing of insert to vector, the DNA is directly used for transformation without a ligation step. This protocol is robust and shows three- to fivefold higher yield of clones compared to previous protocols. No chimeric clones can be detected and the background of clones without an insert is <1%. The procedure is rapid and shows potential for automation.

    Funded by: NHGRI NIH HHS: R01 HG00823

    Analytical biochemistry 1996;236;1;107-13

Gene lists (3)

Gene List Source Species Name Description Gene count
L00000015 G2C Homo sapiens Human NRC Human orthologues of mouse NRC adapted from Collins et al (2006) 186
L00000016 G2C Homo sapiens Human PSP Human orthologues of mouse PSP adapted from Collins et al (2006) 1121
L00000036 G2C Homo sapiens Pocklington H5 Human orthologues of cluster 5 (mouse) from Pocklington et al (2006) 5
© G2C 2014. The Genes to Cognition Programme received funding from The Wellcome Trust and the EU FP7 Framework Programmes:
EUROSPIN (FP7-HEALTH-241498), SynSys (FP7-HEALTH-242167) and GENCODYS (FP7-HEALTH-241995).

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