The Potential Role of BRCA1-Associated ATM Activator-1 (BRAT1) in Regulation of mTOR.

BRCA1-associated ATM activator-1 (BRAT1) was identified by our group as a DNA damage response (DDR) protein, which can bind with many DDR proteins and regulates their functions after DNA damage. However, previous study has also implicated BRAT1 as a regulator of cell growth and apoptosis. In this study, targeted gene deletion showed that BRAT1 is critical in stability and serum-induced expression of mTOR and downstream protein. Conditional deletion of BRAT1 of mouse embryonic fibroblasts suppressed serum-induced cell cycling progress. Our results suggest that BRAT1 is essential factor for PIKK signaling cascades.