The m-AAA protease processes cytochrome c peroxidase preferentially at the inner boundary membrane of mitochondria.
Mol Biol Cell
; 20(2): 572-80, 2009 Jan.
Article
em En
| MEDLINE
| ID: mdl-19019989
ABSTRACT
The m-AAA protease is a conserved hetero-oligomeric complex in the inner membrane of mitochondria. Recent evidence suggests a compartmentalization of the contiguous mitochondrial inner membrane into an inner boundary membrane (IBM) and a cristae membrane (CM). However, little is known about the functional differences of these subdomains. We have analyzed the localizations of the m-AAA protease and its substrate cytochrome c peroxidase (Ccp1) within yeast mitochondria using live cell fluorescence microscopy and quantitative immunoelectron microscopy. We find that the m-AAA protease is preferentially localized in the IBM. Likewise, the membrane-anchored precursor form of Ccp1 accumulates in the IBM of mitochondria lacking a functional m-AAA protease. Only upon proteolytic cleavage the mature form mCcp1 moves into the cristae space. These findings suggest that protein quality control and proteolytic activation exerted by the m-AAA protease take place preferentially in the IBM pointing to significant functional differences between the IBM and the CM.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Metaloendopeptidases
/
Adenosina Trifosfatases
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Citocromo-c Peroxidase
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Proteínas de Saccharomyces cerevisiae
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Membranas Mitocondriais
Limite:
Animals
/
Humans
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article