BCL ‐ XL binds and antagonizes RASSF 6 tumor suppressor to suppress p53 expression

RASSF 6, a member of the tumor suppressor Ras‐association domain family proteins, induces apoptosis in the caspase‐dependent and caspase‐independent manners. RASSF 6 interacts with MDM 2 and stabilizes p53. BCL ‐ XL is a prosurvival member of BCL ‐2 family proteins. BCL ‐ XL directly inhibits proapoptotic BAX and BAK . BCL ‐ XL also traps tBID , a proapoptotic activator BH 3‐only protein, and sequesters p53. In addition, BCL ‐ XL regulates the mitochondrial membrane permeability via voltage‐dependent anion channel. In these manners, BCL ‐ XL plays an antiapoptotic role. We report the interaction of BCL ‐ XL with RASSF 6. BCL ‐ XL inhibits the interaction between RASSF 6 and MDM 2 and suppresses p53 expression. Consequently, BCL ‐ XL antagonizes RASSF 6‐mediated apoptosis. Thus, the inhibition of RASSF 6‐mediated apoptosis also underlies the prosurvival role of BCL ‐ XL .