Probably together with ced-9, plays a modest role in preventing ced-4 and caspase ced-3-mediated apoptosis. Found in a complex composed of ced-3, ced-4 and mac-1 or of ced-9, ced-4 and mac-1. Within the complex, interacts with ced-4. RNAi-mediated knockdown causes an arrest at the L2-L3 larval stages with few adults reaching adulthood. Abnormal presence of vacuoles in the intestine with some intestinal sections almost completely degraded. RNAi-mediated knockdown in a ced-3 (n718) or ced-4 (n1416) mutant background causes a similar arrest at the L2-L3 larval stages. Belongs to the AAA ATPase family.