Negative regulation of p53 by Ras superfamily protein RBEL1A.

ABSTRACT: We had previously reported that RBEL1A, a novel Ras-like GTPase, was overexpressed in multiple human malignancies and that its depletion suppressed cell growth. However, the underlying molecular mechanism remained to be elucidated. Here we report that depletion of endogenous RBEL1A results in p53 accumulation due to increased p53 half-life whereas increased expression of RBEL1A reduces p53 levels under unstressed and genotoxic stress conditions. RBEL1A directly interacts with p53 and MDM2, and strongly enhances MDM2-dependent p53 ubiquitylation and degradation. We also found that RBEL1A modulation of p53 ubiquitylation by MDM2 does not depend on its GTPase activity. We have also defined the p53 oligomeric domain and RBEL1A GTPase domain to be the crucial regions for p53-RBEL1A interactions

SUBMITTER: Lui K 

PROVIDER: S-EPMC3679486 | biostudies-literature | 2013 Jun

REPOSITORIES: biostudies-literature