The mitochondrial PHB complex: roles in mitochondrial respiratory complex assembly, ageing and degenerative disease.

摘要: Although originally identified as putative negative regulators of the cell cycle, recent studies have demonstrated that PHB proteins act a chaperone in assembly subunits mitochondrial respiratory chain complexes. The two proteins, Phblp and Phb2p, are located inner membrane where they form large complex represents novel type membrane-bound chaperone. On basis its native molecular weight, PHB-complex should contain 12-14 copies both Phb2p. binds directly to newly synthesised translation products stabilises them against degradation by metalloproteases belonging family triple-A proteins. Sequence homology assigns Phb1p Phb2p which also contains stomatins, HflKC, flotillins plant defence However, date only bacterial HflKC been shown possess direct functional with complex. Previously assigned actions including roles tumour suppression, cycle regulation, immunoglobulin M receptor binding apoptosis seem unlikely view any hard evidence their support. Nevertheless, because probably indirectly involved ageing cancer, we assess possible role these processes. Finally, suggest original name for prohibitins, be amended reflect hold badly formed subunits, thereby keeping nomenclature already use but altering meaning true function more accurately.