| http://identifiers.org/unip... | biopax3:comment | FUNCTION: Serine/threonine kinase which acts as an essential component of the MAP kinase signal transduction pathway. MAPK1/ERK2 and MAPK3/ERK1 are the 2 MAPKs which play an important role in the MAPK/ERK cascade. They participate also in a signaling cascade initiated by activated KIT and KITLG/SCF. Depending on the cellular context, the MAPK/ERK cascade mediates diverse biological functions such as cell growth, adhesion, survival and differentiation through the regulation of transcription, translation, cytoskeletal rearrangements. The the MAPK/ERK cascade plays also a role in initiation and regulation of meiosis, mitosis, and postmitotic functions in differentiated cells by phosphorylating a number of transcription factors. About 160 substrates have already been discovered for ERKs. Many of these substrates are localized in the nucleus, and seem to participate in the regulation of transcription upon stimulation. However, other substrates are found in the cytosol as well as in other cellular organelles, and those are responsible for processes such as translation, mitosis and apoptosis. Moreover, the MAPK/ERK cascade is also involved in the regulation of the endosomal dynamics, including lysosome processing and endosome cycling through the perinuclear recycling compartment (PNRC); as well as in the fragmentation of the Golgi apparatus during mitosis. The substrates include transcription factors (such as ATF2, BCL6, ELK1, ERF, FOS, HSF4 or SPZ1), cytoskeletal elements (such as CANX, CTTN, GJA1, MAP2, MAPT, PXN, SORBS3 or STMN1), regulators of apoptosis (such as BAD, BTG2, CASP9, DAPK1, IER3, MCL1 or PPARG), regulators of translation (such as EIF4EBP1) and a variety of other signaling-related molecules (like ARHGEF2, DCC, FRS2 or GRB10). Protein kinases (such as RAF1, RPS6KA1/RSK1, RPS6KA3/RSK2, RPS6KA2/RSK3, RPS6KA6/RSK4, SYK, MKNK1/MNK1, MKNK2/MNK2, RPS6KA5/MSK1, RPS6KA4/MSK2, MAPKAPK3 or MAPKAPK5) and phosphatases (such as DUSP1, DUSP4, DUSP6 or DUSP16) are other substrates which enable the propagation the MAPK/ERK signal to additionnal cytosolic and nuclear targets, thereby extending the specificity of the cascade. FUNCTION: Acts as a transcriptional repressor. Binds to a [GC]AAA[GC] consensus sequence. Repress the expression of interferon gamma-induced genes. Seems to bind to the promoter of CCL5, DMP1, IFIH1, IFITM1, IRF7, IRF9, LAMP3, OAS1, OAS2, OAS3 and STAT1. Transcriptional activity is independent of kinase activity (By similarity). CATALYTIC ACTIVITY: ATP + a protein = ADP + a phosphoprotein. COFACTOR: Magnesium (By similarity). ENZYME REGULATION: Phosphorylated by MAP2K1/MEK1 and MAP2K2/MEK2 on Thr-183 and Tyr-185 in response to external stimuli like insulin or NGF. Both phosphorylations are required for activity. This phosphorylation causes dramatic conformational changes, which enable full activation and interaction of MAPK1/ERK2 with its substrates. Phosphorylation on Ser-27 by SGK1 results in its activation by enhancing its interaction with MAP2K1/MEK1 and MAP2K2/MEK2. Dephospphorylated and inactivated by DUSP3, DUSP6 and DUSP9. Inactivated by pyrimidylpyrrole inhibitors. SUBUNIT: Binds both upstream activators and downstream substrates in multimolecular complexes. Interacts with ADAM15, ARHGEF2, ARRB2, DAPK1 (via death domain), HSF4, IER3, IPO7, MKNK2, DUSP6, MORG1, NISCH, PEA15, SGK1, and isoform 1 of NEK2 (By similarity). Interacts (phosphorylated form) with CAV2 ('Tyr-19'-phosphorylated form); the interaction, promoted by insulin, leads to nuclear location and MAPK1 activation (By similarity). MKNK2 isoform 1 binding prevents from dephosphorylation and inactivation (By similarity). Interacts with DCC. SUBCELLULAR LOCATION: Nucleus (By similarity). Cytoplasm, cytoskeleton, centrosome (By similarity). Cytoplasm (By similarity). Note=PEA15-binding and phosphorylated DAPK1 promote its cytoplasmic retention (By similarity). Phosphorylation at Ser- 244 and Ser-246 as well as autophosphorylation at Thr-188 promote nuclear localization (By similarity). TISSUE SPECIFICITY: Highest levels within the nervous system, expressed in different tissues, mostly in muscle, thymus and heart. DEVELOPMENTAL STAGE: Increased expression during development. DOMAIN: The TXY motif contains the threonine and tyrosine residues whose phosphorylation activates the MAP kinases. PTM: Dually phosphorylated on Thr-183 and Tyr-185, which activates the enzyme. Phosphorylated upon FLT3 and KIT signaling. Ligand- activated ALK induces tyrosine phosphorylation (By similarity). Dephosphorylated by PTPRJ at Tyr-185 (By similarity). Autophosphorylated on threonine and tyrosine residues in vitro, which correlates with a slow and low level of activation. Phosphorylation on Ser-27 by SGK1 results in its activation by enhancing its interaction with MAP2K1/MEK1 and MAP2K2/MEK2 (By similarity). SIMILARITY: Belongs to the protein kinase superfamily. CMGC Ser/Thr protein kinase family. MAP kinase subfamily. SIMILARITY: Contains 1 protein kinase domain. GENE SYNONYMS:Mapk1 Erk2 Mapk Prkm1. COPYRIGHT: Protein annotation is derived from the UniProt Consortium (http://www.uniprot.org/). Distributed under the Creative Commons Attribution-NoDerivs License. | lld:biopax3 |
