P38A
a proline-directed ser/thr MAP kinase, and one of four p38 kinases that play important roles in cellular responses to inflammatory cytokines, DNA damage, oxidative stress, and some GPCRs, leading to direct activation of transcription factors and of other downstream kinases including MSK1, MSK2, eEF2K, MK2, and PRAK. MSK1 and -2 play important roles in the rapid induction of immediate-early genes in response to stress or mitogenic stimuli. MK2 and -3 control gene expression mostly at the post-transcriptional level. eEF2K is important for the elongation of mRNA during translation. Ectodomain shedding of transmembrane proteins is regulated by p38 MAPKs as well. In response to inflammatory stimuli, p38 MAPKs phosphorylate the membrane-associated metalloprotease ADAM17, which then cleaves the ectodomain of TGF-alpha family ligands, a process leading to the activation of EGFR signaling and cell proliferation. In the nucleus, many transcription factors are phosphorylated and activated by p38 MAPKs in response to different stimuli. Classical examples include ATF1, ATF2, ATF6, ELK1, PTPRH, CHOPO, p53 and MEF2C and MEF2A. The p38 MAPKs are emerging as important modulators of gene expression by regulating chromatin modifiers and remodelers. The promoters of several genes involved in the inflammatory response, such as IL6, IL8 and IL12B, display a p38 MAPK-dependent enrichment of histone H3 phosphorylation on 'Ser-10' (H3S10ph) in LPS-stimulated myeloid cells. Interacts directly with HDAC3 interacts directly and selectively to repress ATF2 transcriptional activity, and regulate TNF gene expression in LPS-stimulated cells. Phosphorylates the ubiquitin ligase SIAH2, regulating its activity towards EGLN3. May also inhibit the lysosomal degradation pathway of autophagy by interfering with the intracellular trafficking of the transmembrane protein ATG9. Regulates the endocytosis of membrane receptors that depend on RAB5A. Regulates the clathrin-mediated internalization of EGFR induced by inflammatory cytokines and UV irradiation by phosphorylating the EGFR and RAB5A effectors. Required in mid-fetal development for the growth of embryo-derived blood vessels in the labyrinth layer of the placenta. Plays an essential role in developmental and stress-induced erythropoiesis, through regulation of EPO gene expression. Interacts with casein kinase II subunits CSNK2A1 and CSNK2B. Activated by cell stresses such as DNA damage, heat shock, osmotic shock, anisomycin and sodium arsenite, as well as pro-inflammatory stimuli such as LPS and IL-1. Phosphorylated by ZAP70 in an alternative activation pathway in response to TCR signaling in T-cells, a pathway is inhibited by GADD45A. Four alternatively spliced isoforms of the human protein have been observed. Isoform MXI2 activation is stimulated by mitogens and oxidative stress and only poorly phosphorylates ELK1 and ATF2. Isoform EXIP may play a role in the early onset of apoptosis Note: This description may include information from UniProtKB.
Protein type: Kinase, protein; Protein kinase, Ser/Thr (non-receptor); EC 2.7.11.24; Protein kinase, CMGC; EC 2.7.1.37; CMGC group; MAPK family; MAPK/p38 subfamily; p38 subfamily
Molecular Function: MAP kinase kinase activity; MAP kinase activity; protein C-terminus binding; protein serine/threonine kinase activity; protein binding; NFAT protein binding; ATP binding
Biological Process: nerve growth factor receptor signaling pathway; activation of MAPK activity; apoptosis; protein amino acid autophosphorylation; protein kinase cascade; cell morphogenesis; stress-activated MAPK cascade; toll-like receptor 3 signaling pathway; osteoclast differentiation; chemotaxis; signal transduction; cell surface receptor linked signal transduction; regulation of transcription factor activity; RNA metabolic process; response to glucose stimulus; lipopolysaccharide-mediated signaling pathway; response to stress; chondrocyte differentiation; angiogenesis; toll-like receptor 4 signaling pathway; platelet activation; skeletal muscle development; transcription, DNA-dependent; positive regulation of erythrocyte differentiation; MyD88-independent toll-like receptor signaling pathway; DNA damage response, signal transduction; glucose metabolic process; Toll signaling pathway; toll-like receptor 1 signaling pathway; mRNA metabolic process; toll-like receptor 2 signaling pathway; MyD88-dependent toll-like receptor signaling pathway; peptidyl-serine phosphorylation; muscle cell differentiation; response to muramyl dipeptide; DNA damage checkpoint; Ras protein signal transduction; toll-like receptor signaling pathway; positive regulation of muscle cell differentiation; innate immune response; striated muscle cell differentiation; gene expression; fatty acid oxidation; positive regulation of transcription from RNA polymerase II promoter; cell motility; vascular endothelial growth factor receptor signaling pathway; blood coagulation
SS: The number of records in which this modification site was determined using site-specific methods. SS methods include amino acid sequencing, site-directed mutagenesis, modification site-specific antibodies, specific MS strategies, etc.
