Bcl-2 Structure

- Bcl-2 family protein members all consist of a general structure of a hydrophobic helix which is surrounded by amphipathic helices

- Bcl-2 proteins exert their function through numerous transmembrane domains

- the outer surface of the mitochondrial membrane is the site of Bcl-2 protein action

- activated forms of Bcl-2 proteins either cause the disruption of the mitochondrial membrane, pro-apoptotic Bcl-2 proteins or prevent this, anti-apoptotic Bcl-2 proteins

- disruption of the mitochondrial membrane allows for the release of DIABLO and cytochrome c which are both apoptogenic factors which initiate apoptosis

- disruption of the mitochondrial membrane is through the formation of MAC on its surface by Bak or Bax

- blocking is done through direct inhibition of the pro-apoptotic proteins, such as Bax, by Bcl-2 or other anti-apoptotic proteins