PS6K

The protein product of the PS6K gene is known as s6k, p70^s6k, p85^s6k (two isoforms known, encoded by the same gene)
70-kDa S6 protein kinase (p70S6K)

Gene: maps to 17q23. Contains 15 exons extending over ~50 kb.
mRNA: size: ~1.7 kb.
Protein: s6k, the protein product of PS6K, is a serine-threonine kinase whose activation is thought to regulate a wide array of cellular processes involved in the mitogenic response including protein synthesis, translation of specific mRNA species, and cell cycle progression from G₁ to S phase (Couch F.G. et al., 1999)
p70S6 kinase activation is inhibited by rapamycin.

Cell lines:
- PS6K gene amplified (>4-fold) in MCF-7, BT-474, MDA-MB-361. In MCF-7 cells, PS6K amplification appears to be independant of ERBB2 (located at 17q21.1) amplification (Couch F.G. et al, 1999).

Tumors:
- PS6K amplification (and elevated s6k expression) was found in 2/14 breast carcinomas; in one case, this amplification was independent of ERBB2 amplification (Couch F.G. et al, 1999).

Couch F.G. et al. (1999) Localization of PS6K to chromosomal region 17q23 and determination of its amplification in breast cancer. Cancer Res. 59, 1408-1411.
Grove J.R. et al. (1991) Cloning and expression of two human p70 S6 kinase polypeptides differing only at their amino termini. Mol. Cell. Biol. 11, 5541-5550.
Reinhard C. et al. (1992) a single gene encodes two isoforms of the p70S6 kinase: activation upon mitogenic stimulation. Proc. Natl. Acad. Sci. USA 89, 4052-4056.