an AGC kinase of the RSK family that is required for cell growth and G1 cell cycle progression. Is phosphorylated and activated by mTOR in mitogenic pathways downstream of phosphoinositide 3 kinase (PI3K). Phosphorylates the S6 protein of the 40S ribosomal subunit and is involved in translational control of 5' oligopyrimidine tract mRNAs. Activity is controlled by multiple phosphorylation events located within the catalytic, linker and pseudosubstrate domains. Mouse knockout shows symptoms of insulin resistance, and increased insulin senstivity, resulting in protection against diet-induced obesity. Protein expression and activation upregulated in colon adenocarcinoma cell lines. Increased expression in breast cancer correlated with poor survival. Selectively amplified and overexpressed within the 17q23 breast cancer amplicon. Two isoforms produced by alternative initiation have been reported. Note: This description may include information from UniProtKB.
Protein type: EC 22.214.171.124; Protein kinase, Ser/Thr (non-receptor); Translation; Protein kinase, AGC; Kinase, protein; AGC group; RSK family; p70 subfamily
Molecular Function: protein binding; protein serine/threonine/tyrosine kinase activity; ribosomal protein S6 kinase activity; peptide binding; ATP binding; protein kinase activity
Biological Process: skeletal muscle contraction; TOR signaling pathway; response to glucagon stimulus; positive regulation of translation; apoptosis; response to toxin; positive regulation of smooth muscle cell proliferation; response to glucocorticoid stimulus; negative regulation of insulin receptor signaling pathway; response to lipopolysaccharide; positive regulation of smooth muscle cell migration; signal transduction; positive regulation of mitotic cell cycle; protein amino acid phosphorylation; germ cell development; positive regulation of translational initiation; skeletal muscle atrophy; response to wounding; protein kinase B signaling cascade; response to glucose stimulus; response to nutrient; aging; response to drug; cell migration; phosphoinositide-mediated signaling; response to testosterone stimulus; response to electrical stimulus involved in regulation of muscle adaptation; response to leucine; response to ethanol; long-term memory; response to heat; response to mechanical stimulus; insulin receptor signaling pathway; regulation of glucose import; positive regulation of skeletal muscle growth; G1/S transition of mitotic cell cycle; negative regulation of apoptosis
SS: The number of records in which this modification site was determined using site-specific methods. SS methods include amino acid sequencing, site-directed mutagenesis, modification site-specific antibodies, specific MS strategies, etc.