JNK1/2/3 Antibody - #AF6318

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. Phosphorylates the CLOCK-ARNTL/BMAL1 heterodimer and plays a role in the regulation of the circadian clock. Phosphorylates POU5F1, which results in the inhibition of POU5F1's transcriptional activity and enhances its proteosomal degradation (By similarity).

MAPK9 isoforms display different binding patterns: alpha-1 and alpha-2 preferentially bind to JUN, whereas beta-1 and beta-2 bind to ATF2. However, there is no correlation between binding and phosphorylation, which is achieved at about the same efficiency by all isoforms. JUNB is not a substrate for JNK2 alpha-2, and JUND binds only weakly to it.

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

Cytoplasm. Nucleus.
Note: Colocalizes with POU5F1 in the nucleus.

Interacts with MECOM (By similarity). Interacts with DCLK2 (By similarity). 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 (By similarity). Interacts with NFATC4. 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. Interacts with MAPKBP1. Interacts with POU5F1; phosphorylates POU5F1 at 'Ser-355'. Found in a complex with SH3RF1, RAC2, MAP3K7/TAK1, MAP2K7/MKK7, MAPK8IP1/JIP1 and MAPK8/JNK1 (By similarity).

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

Belongs to the protein kinase superfamily. CMGC Ser/Thr protein kinase family. MAP kinase subfamily.

Serine/threonine-protein kinase involved in various processes such as neuronal proliferation, differentiation, migration 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 MAPK10/JNK3. In turn, MAPK10/JNK3 phosphorylates a number of transcription factors, primarily components of AP-1 such as JUN and ATF2 and thus regulates AP-1 transcriptional activity. Plays regulatory roles in the signaling pathways during neuronal apoptosis. Phosphorylates the neuronal microtubule regulator STMN2. Acts in the regulation of the amyloid-beta precursor protein/APP signaling during neuronal differentiation by phosphorylating APP. Participates also in neurite growth in spiral ganglion neurons. Phosphorylates the CLOCK-ARNTL/BMAL1 heterodimer and plays a role in the photic regulation of the circadian clock. Phosphorylates JUND and this phosphorylation is inhibited in the presence of MEN1.

Dually phosphorylated on Thr-221 and Tyr-223 by MAP2K4 and MAP2K7, which activates the enzyme. MAP2K7 shows a strong preference for Thr-221 while MAP2K4 phosphorylates Tyr-223 preferentially. Weakly autophosphorylated on threonine and tyrosine residues in vitro.

Palmitoylation regulates subcellular location and axonal development.

Cytoplasm. Membrane>Lipid-anchor. Nucleus. Mitochondrion.
Note: Palmitoylation regulates MAPK10 trafficking to cytoskeleton. Recruited to the mitochondria in the presence of SARM1 (By similarity).

Specific to a subset of neurons in the nervous system. Present in the hippocampus and areas, cerebellum, striatum, brain stem, and weakly in the spinal cord. Very weak expression in testis and kidney.

Interacts with MAPKBP1 (By similarity). Interacts with MAPK8IP1/JIP-1 and MAPK8IP3/JIP-3/JSAP1 (By similarity). Interacts with SPAG9/MAPK8IP4/JIP4. Interacts with HDAC9. Interacts with ARRB2; the interaction enhances MAPK10 activation by MAP3K5. Interacts with SARM1 (By similarity). Interacts with JUND; interaction is inhibited in the presence of MEN1.

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

Belongs to the protein kinase superfamily. CMGC Ser/Thr protein kinase family. MAP kinase subfamily.