p15INK4b/CDKN2B Proteins and Enzymes

The normal progression of cells through the cell cycle is under the control of the cyclin dependent protein kinases Cdk4 and Cdk6 which are subject to inhibition by the mitotic inhibitory protein, p16. An isolated member of the p16 family has been designated p15. p15 expression is upregulated approximately 30-fold in TGFbeta-treated human keratinocytes, suggesting that p15 may act as an effector of TGFbeta-mediated cell cycle arrest. The gene encoding p15 has been mapped to chromosome 9p21 at a position adjacent to the p16 gene at a site of frequent chromosomal abnormality in human tumors. It has been suggested that p15 may function as an effector of TGFbeta-mediated cell cycle arrest through inhibition of Cdk4 and Cdk6 kinases.