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Updated: Feb 28, 2026

Author Spotlight: Unveiling Mitochondrial Contact Sites and Architectural Insights

Author Spotlight: Unveiling Mitochondrial Contact Sites and Architectural Insights

Published on: June 16, 2023

ミトコンドリア膜輸入複合体は脂質代謝酵素Ayr1に結合し、ミトコンドリアと脂質液滴の接触を促進する

Sandra Heinen¹, Vitasta Tiku¹, Alexander Grevel^2,3

¹Institute of Biochemistry and Molecular Biology, Faculty of Medicine, University of Bonn, Bonn, Germany.

Nature cell biology

|February 26, 2026

Abstract:

Mitochondria play central roles in the energetics and metabolism of eukaryotic cells. Their outer membrane is essential for protein transport, membrane dynamics, signalling and metabolic exchange with other cellular compartments. The mitochondrial import (MIM) complex functions as main translocase for importing the precursors of more than 90% of integral outer-membrane proteins. Here we report that the MIM complex performs a second major function in lipid-droplet homeostasis. Lipid droplets are crucial in cellular lipid metabolism and as storage organelles for neutral lipids. The lipid metabolism enzyme Ayr1 captures the MIM complex, promoting the formation of mitochondria-lipid droplet contact sites. MIM and Ayr1 enhance the lipid droplet number in cells. Ayr1 binds to MIM via its single hydrophobic segment in a substrate-mimicry mechanism but remains bound and is not released into the outer membrane. The functional diversity is mediated by different MIM complexes: MIM-Ayr1 for recruiting lipid droplets and MIM-preprotein for protein insertion into the outer membrane. Our work uncovers translocase capture as a mechanism for functional conversion of a membrane protein complex from protein insertion to lipid metabolism.

キーワード:

ミトコンドリア膜輸入複合体脂質液滴恒常性 Ayr1 タンパク質輸送機能変換

さらに関連する動画

Lipid Droplet Isolation for Quantitative Mass Spectrometry Analysis

Lipid Droplet Isolation for Quantitative Mass Spectrometry Analysis

Published on: April 17, 2017

Isolation of Cellular Lipid Droplets: Two Purification Techniques Starting from Yeast Cells and Human Placentas

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Published on: April 1, 2014

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