Co-translational biogenesis of lipid droplet integral membrane proteins.

Autor: Leznicki P; School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9PT, UK., Schneider HO; Department of Chemistry, Ball State University, Muncie, IN 47306, USA., Harvey JV; Department of Chemistry, Ball State University, Muncie, IN 47306, USA., Shi WQ; Department of Chemistry, Ball State University, Muncie, IN 47306, USA., High S; School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9PT, UK.
Jazyk: angličtina
Zdroj: Journal of cell science [J Cell Sci] 2022 Mar 01; Vol. 135 (5). Date of Electronic Publication: 2021 Nov 02.
DOI: 10.1242/jcs.259220
Abstrakt: Membrane proteins destined for lipid droplets (LDs), a major intracellular storage site for neutral lipids, are inserted into the endoplasmic reticulum (ER) and then trafficked to LDs where they reside in a hairpin loop conformation. Here, we show that LD membrane proteins can be delivered to the ER either co- or post-translationally and that their membrane-embedded region specifies pathway selection. The co-translational route for LD membrane protein biogenesis is insensitive to a small molecule inhibitor of the Sec61 translocon, Ipomoeassin F, and instead relies on the ER membrane protein complex (EMC) for membrane insertion. This route may even result in a transient exposure of the short N termini of some LD membrane proteins to the ER lumen, followed by putative topological rearrangements that would enable their transmembrane segment to form a hairpin loop and N termini to face the cytosol. Our study reveals an unexpected complexity to LD membrane protein biogenesis and identifies a role for the EMC during their co-translational insertion into the ER.
Competing Interests: Competing interests The authors declare no competing or financial interests.
(© 2021. Published by The Company of Biologists Ltd.)
Databáze: MEDLINE
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