cd06646: STKc_MAP4K5 (this model, PSSM-Id:132977 is obsolete and has been replaced by 270813)
Catalytic domain of the Protein Serine/Threonine Kinase, Mitogen-activated protein kinase kinase kinase kinase 5
Serine/threonine kinases (STKs), mitogen-activated protein kinase (MAPK) kinase kinase kinase 5 (MAPKKKK5 or MAP4K5) subfamily, catalytic (c) domain. STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. The MAP4K5 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. Members of this subfamily contain an N-terminal catalytic domain and a C-terminal citron homology (CNH) regulatory domain, similar to MAP4K4/6. MAP4Ks are involved in some MAPK signaling pathways that are important in mediating cellular responses to extracellular signals by activating a MAPK kinase kinase (MAPKKK or MAP3K or MKKK). Each MAPK cascade is activated either by a small GTP-binding protein or by an adaptor protein, which transmits the signal either directly to a MAP3K to start the triple kinase core cascade or indirectly through a mediator kinase, a MAP4K. MAP4K5, also called germinal center kinase-related enzyme (GCKR), has been shown to activate the MAPK c-Jun N-terminal kinase (JNK). MAP4K5 also facilitates Wnt signaling in B cells, and may therefore be implicated in the control of cell fate, proliferation, and polarity.