Molecular biology of Bax and Bak activation and action

► During apoptosis, Bax and Bak puncture the mitochondrial outer membrane. ► Bax and Bak activity is regulated by other members of the Bcl-2 family. ► Activation exposes the Bax and Bak BH3 domains to allow oligomerization. ► Bax and Bak oligomers form pores in the outer membrane via unknown mechanisms. ► Structures of oligomeric Bax or Bak may reveal novel drug targets.