This gene encodes a member of the RSK (ribosomal S6 kinase) family of serine/threonine kinases. This kinase contains 2 non-identical 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. Mutations in this gene have been associated with Coffin-Lowry syndrome (CLS).,RPS6KA3,CLS,HU-3,ISPK-1,MAPKAPK1B,MRX19,RSK,RSK2,S6K-alpha3,p90-RSK2,pp90RSK2,Epigenetics & Nuclear Signaling,Translation Control,Regulation of eIF4 and p70 S6 Kinase,Signal Transduction,G protein signaling,G2/M DNA Damage Checkpoint,Kinase,Serine/threonine kinases,mTOR Signaling Pathway,MAPK-Erk Signaling Pathway,Cell Biology & Developmental Biology,Apoptosis,Mitochondrial Control of Apoptosis,Inhibition of Apoptosis,Cell Cycle,G2/M DNA Damage Checkpoint,Microtubules,Immunology & Inflammation,Neuroscience,RPS6KA3