P70-S6 Kinase 1

Ribosomal protein S6 kinase beta-1 is an enzyme that in humans is encoded by the RPS6KB1 gene.

Function

This gene encodes a member of the RSK family of serine/threonine kinases. This kinase contains 2 non-identical kinase catalytic domains and phosphorylates several residues of the S6 ribosomal protein. The kinase activity of this protein leads to an increase in protein synthesis and cell proliferation. Amplification of the region of DNA encoding this gene and overexpression of this kinase are seen in some breast cancer cell lines. Alternate translational start sites have been described and alternate transcriptional splice variants have been observed but have not been thoroughly characterized.

Clinical significance

Inhibition of the S6K1 protein, or a lack of it, slows the production of adipose (fat) cells by disrupting and retarding the initial "commitment stage" of their formation. The study could have implications for the treatment of obesity.

Amplification of the region of DNA encoding this gene and overexpression of this kinase are seen in some breast cancer cell lines.