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: CMGC group; EC 18.104.22.168; Kinase, protein; MAPK family; MAPK/p38 subfamily; Protein kinase, CMGC; Protein kinase, Ser/Thr (non-receptor); p38 subfamily
Molecular Function: ATP binding; enzyme binding; kinase activity; MAP kinase activity; mitogen-activated protein kinase p38 binding; NFAT protein binding; protein binding; protein C-terminus binding; protein kinase activity; protein phosphatase binding; protein serine/threonine kinase activity
Biological Process: angiogenesis; cartilage condensation; cell morphogenesis; chondrocyte differentiation; DNA damage checkpoint; DNA damage response, signal transduction; fatty acid oxidation; glucose metabolic process; lipopolysaccharide-mediated signaling pathway; myoblast cell differentiation involved in skeletal muscle regeneration; osteoclast differentiation; peptidyl-serine phosphorylation; placenta development; positive regulation of cardiac muscle cell proliferation; positive regulation of cyclase activity; positive regulation of cytokine secretion during immune response; positive regulation of erythrocyte differentiation; positive regulation of glucose import; positive regulation of myoblast differentiation; positive regulation of protein import into nucleus; positive regulation of transcription from RNA polymerase II promoter; protein amino acid autophosphorylation; protein amino acid phosphorylation; regulation of ossification; regulation of transcription from RNA polymerase II promoter; regulation of transcription, DNA-dependent; response to DNA damage stimulus; response to lipopolysaccharide; response to muramyl dipeptide; skeletal muscle development; stress-activated MAPK cascade; striated muscle cell differentiation; transmembrane receptor protein serine/threonine kinase signaling pathway; vascular endothelial growth factor receptor signaling pathway