BCL-2 IS LOCATED PREDOMINANTLY IN THE INNER MEMBRANE AND CRISTA OF MITOCHONDRIA IN RAT-LIVER

Bcl-2 is now recognized as a potent inhibitor of apoptotic cell death. It has been reported that Bcl-2 is located in the mitochondria, endop lasmic reticulum, and nuclear membrane in some cell lines, and it is n ot expressed in normal human and rat liver. An earlier study showed th at Bcl-2 is an inner mitochondrial membrane protein. On the contrary, the following investigations using immunoelectron microscopy demonstra ted that Bcl-2 resides predominantly in the mitochondrial outer membra ne. In this study, using a cryo-sectioning immunogold labeling techniq ue and immunoblotting, me carefully determined the subcellular localiz ation of Bcl-2. Here we report that Bcl-2 is expressed in normal rat l iver, and it is located predominantly in the inner membrane and crista rather than in the outer membrane of mitochondria. (C) 1998 Academic Press.