Bcl-2 family proteins function primarily through interactions at the mitochondrial membrane. Anti-apoptotic members like Bcl-2, Bcl-xL, and Mcl-1 inhibit apoptosis by binding to and sequestering pro-apoptotic factors. Conversely, pro-apoptotic members such as Bax, Bak, and Bid promote apoptosis by facilitating the release of cytochrome c from mitochondria, which activates downstream caspases that lead to cell death.
