PHB proteins are essential during embryonic development and are required for somatic and germline differentiation in the larval gonad. A deficiency in PHB proteins results in altered mitochondrial biogenesis in body wall muscle cells (PubMed:12794069). Required for clearance of paternal mitochondria after embryonic fertilization (PubMed:28017329). High molecular weight complex that consist of phb-1 and phb-2. Belongs to the prohibitin family.