Death by autophagy

During autophagy, intracellular double membrane structures engulf large sections of cytoplasm, thus targeting the enclosed proteins and organelles for degradation, and effectively slowing down cell metabolism. If carried to its logical extreme, autophagy leads to cell death. This type II, autophagic form of cell death is second only to apoptosis in importance in the world of programmed cell death.

On page 455, Inbal et al. describe some of the first molecules directly linked to the control of autophagic cell death. They suggest that these proteins may constitute a link between the ancient process of autophagic cell death and the more recent phenomenon of apoptosis.

The proteins in question are DAP kinase (DAPk) and DRP-1, two closely related, death-promoting, Ca²⁺/calmodulin-regulated kinases. Inhibiting DAPk slows death caused by many different stimuli, and the kinase is known to act as a...