Q15418, P51812, Q15349, Q9UK32

The Rsk family of proteins, including Rsk-1, Rsk-2, Rsk-3, and the highly homologous Rsk-4, are intracellular serine/threonine kinases that serve as crucial signaling intermediates in response to ligand-activated receptor tyrosine kinases. Rsk-4 is predominantly expressed in brain and kidney, playing a significant role in normal neuronal development and highlighting importance in neurogenesis and potential implications in neurological disorders. Each Rsk family member possesses two non-identical complete kinase catalytic domains, a unique structural feature enhancing functional versatility in cellular signaling pathways. Rsk family members share similarities with other kinases like p70 S6 kinase, suggesting related regulatory roles and emphasizing interconnectedness in cellular processes.