Ribosomal protein S6 kinase (IPR016238)

Short name: Ribosomal_S6_kinase

Overlapping homologous superfamilies

Family relationships



This entry represents ribosomal protein S6 kinase (or p70S6K). S6 kinase is a serine/threonine kinase (STK) that catalyses the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. It contains only one catalytic kinase domain, unlike p90 ribosomal S6 kinases (RSKs). S6 kinase is part of the mammalian target of rapamycin (mTOR) pathway, which is a key regulator of cell growth via the regulation of protein synthesis. Both S6 kinase and eukaryotic initiation factor 4E-binding protein 1 (4EBP-1) are key mTOR effectors of cell growth [PMID: 14761882, PMID: 16679021, PMID: 12415748, PMID: 18092230]. S6 kinase specifically phosphorylates ribosomal protein S6 in response to insulin or several classes of mitogens. S6 kinase is activated by serine/threonine phosphorylation and protein kinase C, and is inactivated by type 2A phosphatase [PMID: 17494629]. S6 kinase interacts with PPP1R9A/neurabin-1 [PMID: 9653190]. S6 kinase also plays a pivotal role glucose homeostasis. Its targets include the insulin receptor substrate IRS-1, among others. Mammals contain two isoforms of S6 kinase, named S6K1 and S6K2 (or S6K-beta).

S6 kinase is part of a larger superfamily that includes the catalytic domains of other protein STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

GO terms

Biological Process

GO:0006468 protein phosphorylation
GO:0007165 signal transduction

Molecular Function

GO:0004674 protein serine/threonine kinase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.