The 'harmless' release of cytochrome c

Release of cytochrome c from the mitochondria plays an integral role in apo ptosis; however, the mechanism by which cytochrome c is released remains on e of the conundrums that has occupied the field. Recently, evidence has eme rged that the commitment to death may be regulated downstream of cytochrome c release; therefore the mechanism of release must be subtle enough for th e cell to recover from this event. In this review, we discuss the evidence that cytochrome c release is mediated by Bcl-2 family proteins in a process that involves only outer membrane permeability but leaves inner membrane e nergization, protein import function and the ultrastructure of mitochondria intact.