The Bcl-2 family is classified into three main groups based on their function and structure: 1. Anti-apoptotic proteins: This group includes Bcl-2, Bcl-xL, and Mcl-1. These proteins prevent apoptosis by inhibiting the pro-apoptotic members. 2. Pro-apoptotic effector proteins: This category comprises Bax and Bak, which promote apoptosis by permeabilizing the mitochondrial outer membrane. 3. BH3-only proteins: This subgroup includes Bid, Bad, and Bim, which act as sensors and initiators of apoptosis by interacting with both anti-apoptotic and pro-apoptotic proteins.
