HOMOLOGOUS P35 PROTEINS OF BACULOVIRUSES SHOW DISTINCTIVE ANTI-APOPTOTIC ACTIVITIES WHICH CORRELATE WITH THE APOPTOSIS-INDUCING ACTIVITY OFEACH VIRUS

The anti-apoptotic activity of p35s from two baculoviruses, Autographa californica nucleopolyhedrovirus (AcNPV) and Bombyx mori NPV (BmNPV), was compared in mammalian cells. AcNPV p35 efficiently blocked apopto sis induced by caspase overexpression, but BmNPV p35 did so very poorl y. Analysis of chimeric p35s and in vitro cleavage of wild type p35s s uggest that the cleavage efficiency of p35 correlates with the blockin g activity. Single amino acid substitutions of BmNPV p35 with those ob served in AcNPV p35, however, resulted in significant loss of its anti -apoptotic activity. We speculate that sequences flanking the cleavage site have uniquely evolved during baculovirus evolution. (C) 1998 Fed eration of European Biochemical Societies.