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Licensed Unlicensed Requires Authentication Published by De Gruyter March 13, 2020

How to get to the other side of the mitochondrial inner membrane – the protein import motor

  • Dejana Mokranjac ORCID logo EMAIL logo
From the journal Biological Chemistry

Abstract

Biogenesis of mitochondria relies on import of more than 1000 different proteins from the cytosol. Approximately 70% of these proteins follow the presequence pathway – they are synthesized with cleavable N-terminal extensions called presequences and reach the final place of their function within the organelle with the help of the TOM and TIM23 complexes in the outer and inner membranes, respectively. The translocation of proteins along the presequence pathway is powered by the import motor of the TIM23 complex. The import motor of the TIM23 complex is localized at the matrix face of the inner membrane and is likely the most complicated Hsp70-based system identified to date. How it converts the energy of ATP hydrolysis into unidirectional translocation of proteins into mitochondria remains one of the biggest mysteries of this translocation pathway. Here, the knowns and the unknowns of the mitochondrial protein import motor are discussed.

Award Identifier / Grant number: MO1944/1-2

Award Identifier / Grant number: MO1944/2-1

Funding statement: I would like to thank Umut Günsel for the help in preparing Figure 3 and the present and past members of my group and of the Mito Club for many stimulating discussions on mitochondrial biology. I am indebted to Dr. Andreas Bracher for his continuous help with and discussions on Hsp70 chaperones. The work in my laboratory is generously supported by Deutsche Forschungsgemeinschaft (Funder Id: http://dx.doi.org/10.13039/501100001659, grants MO1944/1-2 and MO1944/2-1), which I gratefully acknowledge.

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Received: 2020-01-07
Accepted: 2020-02-25
Published Online: 2020-03-13
Published in Print: 2020-05-26

©2020 Walter de Gruyter GmbH, Berlin/Boston

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