Evolution and function of the p35 family of apoptosis inhibitors

Abstract

Apoptosis is a common cellular response to virus infection. However, many viruses have evolved strategies, such as the expression of anti-apoptotic proteins, to combat this response. One such family of anti-apoptotic viral proteins is the p35 family of caspase inhibitors, which are expressed by certain insect viruses. Expression of p35 prevents the host cell from undergoing apoptosis, thereby allowing for propagation of the virus. p35 family members are potent inhibitors of caspases. Members of the family fall into one of three groups that inhibit different classes of caspases. Since the discovery of the first p35 gene in 1991, the anti-apoptotic function of this protein family has been studied extensively. This unique type of protease inhibitor has proven to be extremely useful in the study of apoptosis in experimental settings ranging from nematodes to mammals.