cd06653: STKc_MEKK3_like_1 (this model, PSSM-Id:132984 is obsolete and has been replaced by 270819)
Catalytic domain of MAP/ERK kinase kinase 3-like Protein Serine/Threonine Kinases
Serine/threonine kinases (STKs), MAP/ERK kinase kinase 3 (MEKK3)-like subfamily, catalytic (c) domain, functionally uncharacterized subgroup 1. STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. The MEKK3-like subfamily is part of a larger superfamily that includes the catalytic domains of other protein STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase. The MEKK3-like subfamily is composed of MEKK3, MEKK2, and related proteins, all containing an N-terminal PB1 domain, which mediates oligomerization, and a C-terminal catalytic domain. MEKK2 and MEKK3 are mitogen-activated protein kinase (MAPK) kinase kinases (MAPKKKs or MKKKs or MAP3Ks), proteins that phosphorylate and activate MAPK kinases (MAPKKs or MKKs or MAP2Ks), which in turn phosphorylate and activate MAPKs during signaling cascades that are important in mediating cellular responses to extracellular signals. MEKK2 and MEKK3 activate MEK5 (also called MKK5), which activates extracellular signal-regulated kinase 5 (ERK5). The ERK5 cascade plays roles in promoting cell proliferation, differentiation, neuronal survival, and neuroprotection. MEKK3 plays an essential role in embryonic angiogenesis and early heart development. MEKK2 and MEKK3 can also activate the MAPKs, c-Jun N-terminal kinase (JNK) and p38, through their respective MAPKKs.