JNK2 Recombinant Protein

The protein encoded by this gene is a member of the MAP kinase family. MAP kinases are multifunctional proteins. They are involved in a wide variety of cellular processes such as growth, proliferation, differentiation, transcription regulation, and development. They function in stress responses, apoptosis, inflammation and transformation. For example, this kinase plays a dominant role in mediating proliferation of lung cancer and prostate cancer cells, and in regulation of osmotic stress-induced tight junction disruption. Several alternatively spliced transcript variants encoding distinct isoforms have been reported. [provided by RefSeq, Jul 2012]

Function: Serine/threonine-protein kinase involved in various processes such as cell proliferation, differentiation, migration, transformation and programmed cell death. Extracellular stimuli such as proinflammatory cytokines or physical stress stimulate the stress-activated protein kinase/c-Jun N-terminal kinase (SAP/JNK) signaling pathway. In this cascade, two dual specificity kinases MAP2K4/MKK4 and MAP2K7/MKK7 phosphorylate and activate MAPK9/JNK2. In turn, MAPK9/JNK2 phosphorylates a number of transcription factors, primarily components of AP-1 such as JUN and ATF2 and thus regulates AP-1 transcriptional activity. In response to oxidative or ribotoxic stresses, inhibits rRNA synthesis by phosphorylating and inactivating the RNA polymerase 1-specific transcription initiation factor RRN3. Promotes stressed cell apoptosis by phosphorylating key regulatory factors including TP53 and YAP1. In T-cells, MAPK8 and MAPK9 are required for polarized differentiation of T-helper cells into Th1 cells. Upon T-cell receptor (TCR) stimulation, is activated by CARMA1, BCL10, MAP2K7 and MAP3K7/TAK1 to regulate JUN protein levels. Plays an important role in the osmotic stress-induced epithelial tight-junctions disruption. When activated, promotes beta-catenin/CTNNB1 degradation and inhibits the canonical Wnt signaling pathway. Participates also in neurite growth in spiral ganglion neurons

By similarity.

Catalytic activity: ATP + a protein = ADP + a phosphoprotein.

Cofactor: Magnesium

By similarity.

Enzyme regulation: Activated by threonine and tyrosine phosphorylation by either of two dual specificity kinases, MAP2K4 and MAP2K7. MAP2K4 shows a strong preference for Tyr-185 while MAP2K7 phosphorylates Tyr-183 preferentially. Inhibited by dual specificity phosphatases, such as DUSP1

By similarity.

Subunit structure: Binds to at least four scaffolding proteins, MAPK8IP1/JIP-1, MAPK8IP2/JIP-2, MAPK8IP3/JIP-3/JSAP1 and SPAG9/MAPK8IP4/JIP-4. These proteins also bind other components of the JNK signaling pathway. Interacts with NFATC4 and DCLK2. Interacts with ATF7; the interaction does not phosphorylate ATF7 but acts as a docking site for ATF7-associated partners such as JUN. Interacts with BCL10. Interacts with CTNNB1 and GSK3B

By similarity. Interacts with MECOM. Ref.2

Subcellular location: Cytoplasm

By similarity. Nucleus

By similarity.

Domain: The TXY motif contains the threonine and tyrosine residues whose phosphorylation activates the MAP kinases.

Post-translational modification: Dually phosphorylated on Thr-183 and Tyr-185 by MAP2K7 and MAP2K4, which activates the enzyme. Autophosphorylated in vitro

By similarity.

Sequence similarities: Belongs to the protein kinase superfamily. CMGC Ser/Thr protein kinase family. MAP kinase subfamily.Contains 1 protein kinase domain.