Catalytic domain of the Serine/Threonine Kinase, p38alpha Mitogen-Activated Protein Kinase (also called MAPK14)
STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. p38alpha/MAPK14 is expressed in most tissues and is the major isoform involved in the immune and inflammatory response. It is the central p38 MAPK involved in myogenesis. It plays a role in regulating cell cycle check-point transition and promoting cell differentiation. p38alpha also regulates cell proliferation and death through crosstalk with the JNK pathway. Its substrates include MAPK activated protein kinase 2 (MK2), MK5, and the transcription factors ATF2 and Mitf. p38 kinases MAPKs, serving as important mediators of cellular responses to extracellular signals. They are activated by the MAPK kinases MKK3 and MKK6, which in turn are activated by upstream MAPK kinase kinases including TAK1, ASK1, and MLK3, in response to cellular stresses or inflammatory cytokines. The p38alpha subfamily is part of a larger superfamily that includes the catalytic domains of other STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.