Phosphorylation of Bcl-xL by ERK1

The anti-apoptotic function of Bcl-xL in the heart against reperfusion injury is diminished by K-Ras-Mst1-mediated phosphorylation of Ser14, which allows dissociation of Bcl-xL from Bax and promotes cardiomyocyte death. Here we show that Ser14 phosphorylation of Bcl-xL is also promoted by hemodynamic stress in the heart, through the H-Ras-ERK pathway. Our study suggests that phosphorylation of Bcl-xL at Ser14 in response to acute pressure overload plays an essential role in mediating compensatory hypertrophy by promoting calcium release, alleviating the negative constraint of Bcl-xL upon the IP3R-NFAT pathway.