Prohibitin probably acts as a holdase/unfoldase for the stabilization of newly synthesized mitochondrial proteins. Has an antiproliferative activity. Regulates replicative life span (By similarity). The mitochondrial prohibitin complex consists of two subunits (PHB1 and PHB2), assembled into a membrane-associated ring-shaped supercomplex of approximately 1 mDa. Belongs to the prohibitin family.