Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

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

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

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

Loading next page...
 
/lp/springer-journals/the-mitochondrial-phb-complex-roles-in-mitochondrial-respiratory-isXb08TmPx

References (66)

Publisher
Springer Journals
Copyright
Copyright © 2002 by Birkhäuser Verlag,
Subject
Life Sciences; Cell Biology; Biomedicine, general; Life Sciences, general; Biochemistry, general
ISSN
1420-682X
eISSN
1420-9071
DOI
10.1007/s00018-002-8411-0
Publisher site
See Article on Publisher Site

Abstract

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

Journal

Cellular and Molecular Life SciencesSpringer Journals

Published: Jan 1, 2002

There are no references for this article.