Serine 15 phosphorylation of p53 directs its interaction with B56gamma and the tumor suppressor activity of B56gamma-specific protein phosphatase 2A.

ABSTRACT: Earlier studies have demonstrated a functional link between B56gamma-specific protein phosphatase 2A (B56gamma-PP2A) and p53 tumor suppressor activity. Upon DNA damage, a complex including B56gamma-PP2A and p53 is formed which leads to Thr55 dephosphorylation of p53, induction of the p53 transcriptional target p21, and the inhibition of cell proliferation. Although an enhanced interaction between p53 and B56gamma is observed after DNA damage, the underlying mechanism and its significance in PP2A tumor-suppressive function remain unclear. In this study, we show that the increased interaction between B56gamma and p53 after DNA damage requires ATM-dependent phosphorylation of p53 at Ser15. In addition, we demonstrate that the B56gamma3-induced inhibition of cell proliferation, induction of ce

SUBMITTER: Shouse GP 

PROVIDER: S-EPMC2223295 | biostudies-literature | 2008 Jan

REPOSITORIES: biostudies-literature