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Ergosterol content specifies targeting of tail-anchored proteins to mitochondrial outer membranes

Tail-anchored (TA) proteins have a single C-terminal transmembrane domain, making their biogenesis dependent on posttranslational translocation. Despite their importance, no dedicated insertion machinery has been uncovered for mitochondrial outer membrane (MOM) TA proteins. To decipher the molecular...

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Autores principales: Krumpe, Katrin, Frumkin, Idan, Herzig, Yonatan, Rimon, Nitzan, Özbalci, Cagakan, Brügger, Britta, Rapaport, Doron, Schuldiner, Maya
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The American Society for Cell Biology 2012
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3469509/
https://www.ncbi.nlm.nih.gov/pubmed/22918956
http://dx.doi.org/10.1091/mbc.E11-12-0994
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author Krumpe, Katrin
Frumkin, Idan
Herzig, Yonatan
Rimon, Nitzan
Özbalci, Cagakan
Brügger, Britta
Rapaport, Doron
Schuldiner, Maya
author_facet Krumpe, Katrin
Frumkin, Idan
Herzig, Yonatan
Rimon, Nitzan
Özbalci, Cagakan
Brügger, Britta
Rapaport, Doron
Schuldiner, Maya
author_sort Krumpe, Katrin
collection PubMed
description Tail-anchored (TA) proteins have a single C-terminal transmembrane domain, making their biogenesis dependent on posttranslational translocation. Despite their importance, no dedicated insertion machinery has been uncovered for mitochondrial outer membrane (MOM) TA proteins. To decipher the molecular mechanisms guiding MOM TA protein insertion, we performed two independent systematic microscopic screens in which we visualized the localization of model MOM TA proteins on the background of mutants in all yeast genes. We could find no mutant in which insertion was completely blocked. However, both screens demonstrated that MOM TA proteins were partially localized to the endoplasmic reticulum (ER) in ∆spf1 cells. Spf1, an ER ATPase with unknown function, is the first protein shown to affect MOM TA protein insertion. We found that ER membranes in ∆spf1 cells become similar in their ergosterol content to mitochondrial membranes. Indeed, when we visualized MOM TA protein distribution in yeast strains with reduced ergosterol content, they phenocopied the loss of Spf1. We therefore suggest that the inherent differences in membrane composition between organelle membranes are sufficient to determine membrane integration specificity in a eukaryotic cell.
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spelling pubmed-34695092012-12-30 Ergosterol content specifies targeting of tail-anchored proteins to mitochondrial outer membranes Krumpe, Katrin Frumkin, Idan Herzig, Yonatan Rimon, Nitzan Özbalci, Cagakan Brügger, Britta Rapaport, Doron Schuldiner, Maya Mol Biol Cell Articles Tail-anchored (TA) proteins have a single C-terminal transmembrane domain, making their biogenesis dependent on posttranslational translocation. Despite their importance, no dedicated insertion machinery has been uncovered for mitochondrial outer membrane (MOM) TA proteins. To decipher the molecular mechanisms guiding MOM TA protein insertion, we performed two independent systematic microscopic screens in which we visualized the localization of model MOM TA proteins on the background of mutants in all yeast genes. We could find no mutant in which insertion was completely blocked. However, both screens demonstrated that MOM TA proteins were partially localized to the endoplasmic reticulum (ER) in ∆spf1 cells. Spf1, an ER ATPase with unknown function, is the first protein shown to affect MOM TA protein insertion. We found that ER membranes in ∆spf1 cells become similar in their ergosterol content to mitochondrial membranes. Indeed, when we visualized MOM TA protein distribution in yeast strains with reduced ergosterol content, they phenocopied the loss of Spf1. We therefore suggest that the inherent differences in membrane composition between organelle membranes are sufficient to determine membrane integration specificity in a eukaryotic cell. The American Society for Cell Biology 2012-10-15 /pmc/articles/PMC3469509/ /pubmed/22918956 http://dx.doi.org/10.1091/mbc.E11-12-0994 Text en © 2012 Krumpe et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0). “ASCB®,” “The American Society for Cell Biology®,” and “Molecular Biology of the Cell®” are registered trademarks of The American Society of Cell BD; are registered trademarks of The American Society of Cell Biology.
spellingShingle Articles
Krumpe, Katrin
Frumkin, Idan
Herzig, Yonatan
Rimon, Nitzan
Özbalci, Cagakan
Brügger, Britta
Rapaport, Doron
Schuldiner, Maya
Ergosterol content specifies targeting of tail-anchored proteins to mitochondrial outer membranes
title Ergosterol content specifies targeting of tail-anchored proteins to mitochondrial outer membranes
title_full Ergosterol content specifies targeting of tail-anchored proteins to mitochondrial outer membranes
title_fullStr Ergosterol content specifies targeting of tail-anchored proteins to mitochondrial outer membranes
title_full_unstemmed Ergosterol content specifies targeting of tail-anchored proteins to mitochondrial outer membranes
title_short Ergosterol content specifies targeting of tail-anchored proteins to mitochondrial outer membranes
title_sort ergosterol content specifies targeting of tail-anchored proteins to mitochondrial outer membranes
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3469509/
https://www.ncbi.nlm.nih.gov/pubmed/22918956
http://dx.doi.org/10.1091/mbc.E11-12-0994
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