RSK1 p90 phospho S221

IgG

Human

RSK1 p90

PBS pH 7. 3 (without Mg2+ and Ca2+) containing 50% glycerol 1. 0mg/ml BSA (IgG protease free). and 0. 05% sodium azide.

90 kDa. Not tested in other applications. Optimal dilutions/concentrations should be determined by the end user. RSK1 (also called MAPK Activated Protein Kinase-1a; MAPKAP-K1a) is a member of the broadly expressed p90 Ribosomal S6 Kinase (RSK) family of serine/threonine kinases that also includes RSK2 (MAPKAP-K1b) RSK3 (MAPKAP-K1c) and RSK4. RSK proteins are substrates for and downstream transducers of MAPK signaling proteins primarily ERK1& 2. RSK proteins possess two separate kinase domains the C-terminal kinase domain and the N-terminal kinase domain separated by a linker region containing a hydrophobic motif. Activation of RSK1 is a multi-step process involving phosphorylation of multiple residues within the three domains changes in RSK protein localization and modulation of RSK complex formation with ERK1& 2 and/or 14-3-3 beta proteins. RSK is activated by many stimuli including growth factors phorbol esters cAMP heat shock and irradiation. ERK 1& 2 phosphorylate threonine 573 of the C-terminal kinase domain thereby stimulating this kinase activity and leading to phosphorylation of serine 380 within the linker region. Phosphoserine 380 is part of a docking site for PDK1 a constitutively active cytoplasmic kinase that phosphorylates serine 221 and thereby activates the N-terminal kinase domain to phosphorylate various substrates that include transporters transcription factors and transcription co-activators.

ATP + a protein = ADP + a phosphoprotein. Cofactor: Magnesium.

Forms a complex with either ERK1 or ERK2 in quiescent cells. Transiently dissociates following mitogenic stimulation.

Belongs to the protein kinase superfamily. AGC Ser/Thr protein kinase family. S6 kinase subfamily.

Contains 2 protein kinase domains.