Translocation and insertion of precursor proteins into isolated outer membranes of mitochondria.

Détails

ID Serval
serval:BIB_091343C25FAF
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Translocation and insertion of precursor proteins into isolated outer membranes of mitochondria.
Périodique
Journal of Cell Biology
Auteur(s)
Mayer A., Lill R., Neupert W.
ISSN
0021-9525 (Print)
ISSN-L
0021-9525
Statut éditorial
Publié
Date de publication
1993
Peer-reviewed
Oui
Volume
121
Numéro
6
Pages
1233-1243
Langue
anglais
Résumé
Nuclear-encoded proteins destined for mitochondria must cross the outer or both outer and inner membranes to reach their final sub-mitochondrial locations. While the inner membrane can translocate preproteins by itself, it is not known whether the outer membrane also contains an endogenous protein translocation activity which can function independently of the inner membrane. To selectively study the protein transport into and across the outer membrane of Neurospora crassa mitochondria, outer membrane vesicles were isolated which were sealed, in a right-side-out orientation, and virtually free of inner membranes. The vesicles were functional in the insertion and assembly of various outer membrane proteins such as porin, MOM19, and MOM22. Like with intact mitochondria, import into isolated outer membranes was dependent on protease-sensitive surface receptors and led to correct folding and membrane integration. The vesicles were also capable of importing a peripheral component of the inner membrane, cytochrome c heme lyase (CCHL), in a receptor-dependent fashion. Thus, the protein translocation machinery of the outer mitochondrial membrane can function as an independent entity which recognizes, inserts, and translocates mitochondrial preproteins of the outer membrane and the intermembrane space. In contrast, proteins which have to be translocated into or across the inner membrane were only specifically bound to the vesicles, but not imported. This suggests that transport of such proteins involves the participation of components of the intermembrane space and/or the inner membrane, and that in these cases the outer membrane translocation machinery has to act in concert with that of the inner membrane.
Mots-clé
Biological Transport, Cell Fractionation, Fungal Proteins/metabolism, Intracellular Membranes/metabolism, Membrane Proteins/metabolism, Membrane Transport Proteins, Mitochondria/metabolism, Neurospora crassa, Protein Precursors/metabolism, Receptors, Cell Surface/metabolism, Receptors, Cytoplasmic and Nuclear
Pubmed
Web of science
Open Access
Oui
Création de la notice
24/01/2008 16:06
Dernière modification de la notice
20/08/2019 13:31
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