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FASEB J. 2015 Mar;29(3):820-7. doi: 10.1096/fj.14-259903. Epub 2014 Nov 17.

Mitochondrial membrane potential is regulated by vimentin intermediate filaments.

Author information

1
*Institute of Protein Research, Russian Academy of Sciences, Group of Cell Biology, Moscow, Russia; and Department of Cell and Molecular Biology, Northwestern University's Feinberg School of Medicine, Chicago, Illinois, USA.
2
*Institute of Protein Research, Russian Academy of Sciences, Group of Cell Biology, Moscow, Russia; and Department of Cell and Molecular Biology, Northwestern University's Feinberg School of Medicine, Chicago, Illinois, USA alexminin@gmail.com.

Abstract

This study demonstrates that the association of mitochondria with vimentin intermediate filaments (VIFs) measurably increases their membrane potential. This increase is detected by quantitatively comparing the fluorescence intensity of mitochondria stained with the membrane potential-sensitive dye tetramethylrhodamine-ethyl ester (TMRE) in murine vimentin-null fibroblasts with that in the same cells expressing human vimentin (∼35% rise). When vimentin expression is silenced by small hairpin RNA (shRNA) to reduce vimentin by 90%, the fluorescence intensity of mitochondria decreases by 20%. The increase in membrane potential is caused by specific interactions between a subdomain of the non-α-helical N terminus (residues 40 to 93) of vimentin and mitochondria. In rho 0 cells lacking mitochondrial DNA (mtDNA) and consequently missing several key proteins in the mitochondrial respiratory chain (ρ(0) cells), the membrane potential generated by an alternative anaerobic process is insensitive to the interactions between mitochondria and VIF. The results of our studies show that the close association between mitochondria and VIF is important both for determining their position in cells and their physiologic activity.

KEYWORDS:

cytoskeleton; mitochondrial respiratory chain; rho 0 cells

PMID:
25404709
PMCID:
PMC4422353
DOI:
10.1096/fj.14-259903
[Indexed for MEDLINE]
Free PMC Article

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