This gene encodes a member of the RSK (ribosomal S6 kinase) family of serine/threonine kinases. This kinase contains 2 nonidentical kinase catalytic domains and phosphorylates various substrates, including members of the mitogen-activated kinase (MAPK) signalling pathway. The activity of this protein has been implicated in controlling cell growth and differentiation. Alternate transcriptional splice variants, encoding different isoforms, have been characterized. [provided by RefSeq, Jul 2008],HU-1, MAPKAPK1A, RSK, RSK1, p90Rsk,Apoptosis,Apoptosis_Inhibition of Apoptosis,Apoptosis_Mitochondrial Control of Apoptosis,Cell Biology & Developmental Biology,Cell Cycle,Cytoskeleton_Microtubules,Epigenetics & Nuclear Signaling,G protein signaling,G protein signaling_G-Protein-Coupled Receptors Signaling to MAPK/Erk,G2/M DNA Damage Checkpoint,Immunology & Inflammation,Kinase,Kinase_Serine/threonine kinases,MAPK-Erk Signaling Pathway,mTOR Signaling Pathway,Neuroscience,NF-kB Signaling Pathway,Protein phosphorylation,Signal Transduction,Translation Control,Translational Control_Regulation of eIF4 and p70 S6 Kinase,RPS6KA1