Disease:Defects in MAPK8IP1 are a cause of non-insulin-dependent diabetes mellitus (NIDDM) [MIM:125853]. NIDDM is characterized by an autosomal dominant mode of inheritance , onset during adulthood and insulin resistance. ,Domain:A minimal inhibitory domain prevents pancreatic beta cell apoptosis in vitro , and prevents activation of c-jun by MAPK8 , MAPK9 and MAPK10. ,Domain:The destruction boxes (D-box) may act as recognition signals for degradation via the ubiquitin-proteasome pathway. ,Function:The JNK-interacting protein (JIP) group of scaffold proteins selectively mediates JNK signaling by aggregating specific components of the MAPK cascade to form a functional JNK signaling module. Required for JNK activation in response to excitotoxic stress. Cytoplasmic MAPK8IP1 causes inhibition of JNK-regulated activity by retaining JNK in the cytoplasm and inhibiting JNK phosphorylation of c-Jun. May also participate in ApoER2-specific reelin signaling. Directly , or indirectly , regulates GLUT2 gene expression and beta-cell function. Appears to have a role in cell signaling in mature and developing nerve terminals. May function as a regulator of vesicle transport , through interactions with the JNK-signaling components and motor proteins (By similarity) . Functions as an anti-apoptotic protein and whose level seems to influence the beta-cell death or survival response. ,miscellaneous:A chemically synthesized cell-permeable peptide of the minimal inhibitory domain decreases brain lesions in both transient and permanent ischemia. The level of protection is still high when administered 6 or 12 hours after ischemia. ,PTM:Phosphorylated by MAPK8 , MAPK9 and MAPK10. Phosphorylation on Thr-103 is also necessary for the dissociation and activation of MAP3K12. ,PTM:Ubiquitinated. Two preliminary events are required to prime for ubiquitination; phosphorylation and an increased in intracellular calcium concentration. Then , the calcium influx initiates ubiquitination and degradation by the ubiquitin-proteasome pathway. ,similarity:Belongs to the JIP scaffold family. ,similarity:Contains 1 PID domain. ,similarity:Contains 1 SH3 domain. ,subcellular location:Accumulates in cell surface projections. Under certain stress conditions , translocates to the perinuclear region of neurons. In insulin-secreting cells , detected in both the cytoplasm and nucleus. ,subunit:Forms homo- or heterooligomeric complexes. Binds specific components of the JNK signaling pathway namely , MAPK8 , MAPK9 , MAPK10 , MAPKK7 , MLK2 , MLK3 , MAP3K12 and MAP3K13. Also binds the proline-rich domain-containing splice variant of apolipoprotein E receptor 2 (ApoER2) . Interacts , via the PID domain , with RGNEF. Binds the cytoplasmic tails of LRP1 and LRP2 (Megalin) . Binds the TPR motif-containing C-terminal of KNS2 , then the pre-assembled MAPK8IP1 scaffolding complexes are transported as a cargo of kinesin , to the required subcellular location. Interacts with the cytoplasmic domain of APP. ,tissue specificity:Highly expressed in brain. Expressed in neurons , localizing to neurite tips in differentiating cells. Also expressed in the pancreas , testis and prostate. Low levels in heart , ovary and small intestine. Decreased levels in pancreatic beta cells sensitize cells to IL-1-beta-induced apoptosis. ,
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