Closing in on the link between apoptosis and autophagy

While there is a clear connection between apoptosis and autophagy, the mechanisms that regulate the interaction have been difficult to identify. The initial clue to the link was the observation that Bcl-2 was located at the endoplasmic reticulum (ER), where it could prevent some forms of apoptosis and also bind to the autophagy regulatory protein Beclin-1. However, both of these enigmatic observations have been united with the discovery of the nutrient-deprivation autophagy factor-1 (NAF-1) protein. As an ER-localized protein that enhances the interaction of Bcl-2 and Beclin-1 and that also binds to the pro-apoptotic protein Bik, NAF-1 is perfectly placed to be a central regulator of the switch between autophagy and apoptosis.