BCL-2 AND BAX FUNCTION INDEPENDENTLY TO REGULATE CELL-DEATH

The BCL-2 family has Various pairs of antagonist and agonist proteins that regulate apoptosis, Whether their function is interdependent is u ncertain. Using a genetic approach to address this question, we utiliz ed gain- and loss-of-function models of Bcl-2 and Bar and found that a poptosis and thymic hypoplasia characteristic of Bcl-2-deficient mice are largely absent in mice also deficient in Bax. A single copy of Bar promoted apoptosis in the absence of Bcl-2. In contrast, overexpressi on of Bcl-2 still repressed apoptosis in the absence of Bax. While an in vivo competition exists between Bar and Bcl-2, each is able to regu late apoptosis independently.