1. Biochemistry and Chemical Biology
  2. Cell Biology
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Role of Tim17 in coupling the import motor to the translocation channel of the mitochondrial presequence translocase

  1. Keren Demishtein-Zohary
  2. Umut Günsel
  3. Milit Marom
  4. Rupa Banerjee
  5. Walter Neupert
  6. Abdussalam Azem  Is a corresponding author
  7. Dejana Mokranjac  Is a corresponding author
  1. Tel Aviv University, Israel
  2. Ludwig Maximilian University of Munich, Germany
  3. Max Planck Institute of Biochemistry, Germany
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Cite this article as: eLife 2017;6:e22696 doi: 10.7554/eLife.22696

Abstract

The majority of mitochondrial proteins use N-terminal presequences for targeting to mitochondria and are translocated by the presequence translocase. During translocation, proteins, threaded through the channel in the inner membrane, are handed over to the import motor at the matrix face. Tim17 is an essential, membrane-embedded subunit of the translocase, however, its function is only poorly understood. Here, we functionally dissected its four predicted transmembrane (TM) segments. Mutations in TM1 and TM2 impaired the interaction of Tim17 with Tim23, component of the translocation channel, whereas mutations in TM3 compromised binding of the import motor. We identified residues in the matrix-facing region of Tim17 involved in binding of the import motor. Our results reveal functionally distinct roles of different regions of Tim17 and suggest how they may be involved in handing over the proteins, during their translocation into mitochondria, from the channel to the import motor of the presequence translocase.

Article and author information

Author details

  1. Keren Demishtein-Zohary

    Department of Biochemistry and Molecular Biology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
    Competing interests
    The authors declare that no competing interests exist.
  2. Umut Günsel

    BMC-Physiological Chemistry, Ludwig Maximilian University of Munich, Martinsried, Germany
    Competing interests
    The authors declare that no competing interests exist.
  3. Milit Marom

    Department of Biochemistry and Molecular Biology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
    Competing interests
    The authors declare that no competing interests exist.
  4. Rupa Banerjee

    BMC-Physiological Chemistry, Ludwig Maximilian University of Munich, Munich, Germany
    Competing interests
    The authors declare that no competing interests exist.
  5. Walter Neupert

    Max Planck Institute of Biochemistry, Martinsried, Germany
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-0571-4419
  6. Abdussalam Azem

    Department of Biochemistry and Molecular Biology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
    For correspondence
    azema@tauex.tau.ac.il
    Competing interests
    The authors declare that no competing interests exist.
  7. Dejana Mokranjac

    BMC-Physiological Chemistry, Ludwig Maximilian University of Munich, Martinsried, Germany
    For correspondence
    dejana.mokranjac@med.uni-muenchen.de
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-4005-6979

Funding

German-Israeli Foundation for Scientific Research and Development (GIF- 1012/08)

  • Walter Neupert
  • Abdussalam Azem
  • Dejana Mokranjac

Israel Science Foundation (ISF-1507/13)

  • Abdussalam Azem

Deutsche Forschungsgemeinschaft (MO1944/1-1)

  • Dejana Mokranjac

Deutscher Akademischer Austauschdienst

  • Rupa Banerjee

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Nikolaus Pfanner, University of Freiburg, Germany

Publication history

  1. Received: October 26, 2016
  2. Accepted: February 6, 2017
  3. Accepted Manuscript published: February 6, 2017 (version 1)
  4. Version of Record published: February 14, 2017 (version 2)

Copyright

© 2017, Demishtein-Zohary et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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