cd05613: STKc_MSK1_N (this model, PSSM-Id:173704 is obsolete and has been replaced by 270764)
N-terminal catalytic domain of the Protein Serine/Threonine Kinase, Mitogen and stress-activated kinase 1
Serine/Threonine Kinases (STKs), Mitogen and stress-activated kinase (MSK) subfamily, MSK1, N-terminal catalytic (c) domain. STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. The MSK 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. MSKs contain an N-terminal kinase domain (NTD) from the AGC family and a C-terminal kinase domain (CTD) from the CAMK family, similar to 90 kDa ribosomal protein S6 kinases (RSKs). MSKs are activated by two major signaling cascades, the Ras-MAPK and p38 stress kinase pathways, which trigger phosphorylation in the activation loop (A-loop) of the CTD of MSK. The active CTD phosphorylates the hydrophobic motif (HM) of NTD, which facilitates the phosphorylation of the A-loop and activates the NTD, which in turn phosphorylates downstream targets. MSK1 plays a role in the regulation of translational control and transcriptional activation. It phosphorylates the transcription factors, CREB and NFkappaB. It also phosphorylates the nucleosomal proteins H3 and HMG-14. Increased phosphorylation of MEK1 is associated with the development of cerebral ischemic/hypoxic preconditioning.