Composition and Topology of the Endoplasmic Reticulum¨CMitochondria Encounter Structure
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- 作者：David A. Stroud1 ; ; 2 ; ; 3 ; Silke Oeljeklaus4 ; ; 5 ; Sebastian Wiese4 ; ; 5 ; Maria Bohnert1 ; ; 2 ; Urs Lewandrowski6 ; Albert Sickmann6 ; Bernard Guiard7 ; Martin van der Laan1 ; ; 5 ; Bettina Warscheid4 ; ; 5 ; Nils Wiedemann1 ; ; 5 ; ; Nils.Wiedemann@biochemie.uni-freiburg.de
- 关键词：ERMES ; Gem1 ; Mmm1 ; mitochondrial morphology ; Saccharomyces cerevisiae
- 刊名：Journal of Molecular Biology
- 出版年：2011
- 出版时间：4 November 2011
- 年：2011
- 卷：413
- 期：4
- 页码：743-750
- 全文大小：640 K
文摘
Eukaryotic cells contain multiple organelles, which are functionally and structurally interconnected. The endoplasmic reticulum¨Cmitochondria encounter structure (ERMES) forms a junction between mitochondria and the endoplasmic reticulum (ER). Four ERMES proteins are known in yeast, the ER-anchored protein Mmm1 and three mitochondria-associated proteins, Mdm10, Mdm12 and Mdm34, with functions related to mitochondrial morphology and protein biogenesis. We mapped the glycosylation sites of ERMES and demonstrate that three asparagine residues in the N?terminal domain of Mmm1 are glycosylated. While the glycosylation is dispensable, the cytosolic C?terminal domain of Mmm1 that connects to the Mdm proteins is required for Mmm1 function. To analyze the composition of ERMES, we determined the subunits by quantitative mass spectrometry. We identified the calcium-binding GTPase Gem1 as a new ERMES subunit, revealing that ERMES is composed of five genuine subunits. Taken together, ERMES represents a platform that integrates components with functions in formation of ER¨Cmitochondria junctions, maintenance of mitochondrial morphology, protein biogenesis and calcium binding.