MCB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Truscott, K. N.
Right arrow Articles by Guiard, B.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Truscott, K. N.
Right arrow Articles by Guiard, B.

 Previous Article  |  Next Article 

Molecular and Cellular Biology, November 2002, p. 7780-7789, Vol. 22, No. 22
0270-7306/02/$04.00+0     DOI: 10.1128/MCB.22.22.7780-7789.2002
Copyright © 2002, American Society for Microbiology. All Rights Reserved.

Mitochondrial Import of the ADP/ATP Carrier: the Essential TIM Complex of the Intermembrane Space Is Required for Precursor Release from the TOM Complex

Kaye N. Truscott,1 Nils Wiedemann,1,2 Peter Rehling,1 Hanne Müller,1 Chris Meisinger,1 Nikolaus Pfanner,1* and Bernard Guiard3

Institut für Biochemie und Molekularbiologie,1 Fakultät für Biologie, Universität Freiburg, D-79104 Freiburg, Germany,2 Centre de Génétique Moléculaire, Laboratoire propre du CNRS Université Pierre et Marie Curie, 91190 Gif-sur-Yvette, France3

Received 19 June 2002/ Returned for modification 5 August 2002/ Accepted 16 August 2002

The mitochondrial intermembrane space contains a protein complex essential for cell viability, the Tim9-Tim10 complex. This complex is required for the import of hydrophobic membrane proteins, such as the ADP/ATP carrier (AAC), into the inner membrane. Different views exist about the role played by the Tim9-Tim10 complex in translocation of the AAC precursor across the outer membrane. For this report we have generated a new tim10 yeast mutant that leads to a strong defect in AAC import into mitochondria. Thereby, for the first time, authentic AAC is stably arrested in the translocase complex of the outer membrane (TOM), as shown by antibody shift blue native electrophoresis. Surprisingly, AAC is still associated with the receptors Tom70 and Tom20 when the function of Tim10 is impaired. The nonessential Tim8-Tim13 complex of the intermembrane space is not involved in the transfer of AAC across the outer membrane. These results define a two-step mechanism for translocation of AAC across the outer membrane. The initial insertion of AAC into the import channel is independent of the function of Tim9-Tim10; however, completion of translocation across the outer membrane, including release from the TOM complex, requires a functional Tim9-Tim10 complex.


* Corresponding author. Mailing address: Institut für Biochemie und Molekularbiologie, Universität Freiburg, Hermann-Herder-Str. 7, D-79104 Freiburg, Germany. Phone: 49-761 203 5224. Fax: 49-761 203 5261. E-mail: Nikolaus.Pfanner{at}biochemie.uni-freiburg.de.


Molecular and Cellular Biology, November 2002, p. 7780-7789, Vol. 22, No. 22
0022-538X/02/$04.00+0     DOI: 10.1128/MCB.22.22.7780-7789.2002
Copyright © 2002, American Society for Microbiology. All Rights Reserved.




This article has been cited by other articles:




Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. J. Virol. Eukaryot. Cell
Microbiol. Mol. Biol. Rev. Clin. Vaccine Immunol. All ASM Journals

Copyright © 2002 by the American Society for Microbiology. All rights reserved.