mitogen-activated protein kinase 8 (c-jun NH2 terminal kinase 1, MAPK8 JNK1, PRKM8, JNK46)
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Function
- responds to activation by environmental stress & pro- inflammatory cytokines by phosphorylating a number of transcription factors, primarily components of AP-1 including c-Jun & ATF2 & thus regulates AP-1 transcriptional activity
- In T-cells, JNK1 & JNK2 are required for polarized differentiation of T-helper cells into Th1 cells (putative)
- phosphorylates heat shock factor protein 4 (HSF4)
- JNK1 isoforms display different binding patterns:
- no correlation between binding & phosphorylation, which is achieved at about the same efficiency by all isoforms
- binds to at least four scaffolding proteins, MAPK8IP1/JIP-1, MAPK8IP2/JIP-2, MAPK8IP3/JIP-3/JSAP1 & SPAG9/MAPK8IP4/JIP-4
- these proteins also bind other components of the JNK signaling pathway
- interacts with TP53 & WWOX
- interacts with JAMP (putative)
- activated by Thr & Tyr phosphorylation by either of two dual specificity kinases, MAP2K4 & MAP2K7
- inhibited by dual specificity phosphatases, such as DUSP1
- dually phosphorylated on Thr-183 & Tyr-185, which activates the enzyme
Structure
- TXY motif contains the Thr & Tyr whose phosphorylation activates the MAP kinases
- belongs to the protein kinase superfamily, CMGC Ser/Thr protein kinase family, MAP kinase subfamily
- contains 1 protein kinase domain
More general terms
References
- ↑ Drijard B et al. JNK1: a protein kinase stimulated by UV light and Ha-Ras that binds and phosphorylates the c-Jun activation domain. Cell. 1994 Mar 25;76(6):1025-37. PMID: https://www.ncbi.nlm.nih.gov/pubmed/8137421
- ↑ Lin A, Minden A, Martinetto H, Claret FX, Lange-Carter C, Mercurio F, Johnson GL, Karin M. Identification of a dual specificity kinase that activates the Jun kinases and p38-Mpk2. Science. 1995 Apr 14;268(5208):286-90. PMID: https://www.ncbi.nlm.nih.gov/pubmed/7716521
- ↑ Atlas of genetics & cytogenetics in oncology & Haematology http://atlasgeneticsoncology.org/genes/JNK1ID196.html
- ↑ Wikipedia; Note: C-Jun N-terminal kinases entry http://en.wikipedia.org/wiki/C-Jun_N-terminal_kinase
- ↑ UniProt http://www.uniprot.org/uniprot/P45983.html