COPI buds 60-nm lipid droplets from reconstituted water-phospholipid-triacylglyceride interfaces, suggesting a tension clamp function

• Verfasst von: Thiam, Abdou Rachid [VerfasserIn]
• Verfasst von: Antonny, Bruno [VerfasserIn]
• Verfasst von: Wang, Jing [VerfasserIn]
• Verfasst von: Delacotte, Jérôme [VerfasserIn]
• Verfasst von: Wilfling, Florian [VerfasserIn]
• Verfasst von: Walther, Tobias C. [VerfasserIn]
• Verfasst von: Beck, Rainer [VerfasserIn]
• Verfasst von: Rothman, James E. [VerfasserIn]
• Verfasst von: Pincet, Frédéric [VerfasserIn]
• Titel: COPI buds 60-nm lipid droplets from reconstituted water-phospholipid-triacylglyceride interfaces, suggesting a tension clamp function
• Verf.angabe: Abdou Rachid Thiam, Bruno Antonny, Jing Wang, Jérôme Delacotte, Florian Wilfling, Tobias C. Walther, Rainer Beck, James E. Rothman, and Frédéric Pincet
• E-Jahr: 2013
• Jahr: July 30, 2013
• Umfang: 6 S.
• Fussnoten: Gesehen am 03.02.2022
• Titel Quelle: Enthalten in: National Academy of Sciences (Washington, DC)Proceedings of the National Academy of Sciences of the United States of America
• Ort Quelle: Washington, DC : National Acad. of Sciences, 1915
• Jahr Quelle: 2013
• Band/Heft Quelle: 110(2013), 33, Seite 13244-13249
• ISSN Quelle: 1091-6490
• DOI: doi:10.1073/pnas.1307685110
• Datenträger: Online-Ressource
• Sprache: eng
• Sach-SW: buffer-in-oil drops
• Sach-SW: lipid droplet targetting
• Sach-SW: membrane tension
• Sach-SW: regulator
• K10plus-PPN: 1788455754

Abstract

Intracellular trafficking between organelles is achieved by coat protein complexes, coat protomers, that bud vesicles from bilayer membranes. Lipid droplets are protected by a monolayer and thus seem unsuitable targets for coatomers. Unexpectedly, coat protein complex I (COPI) is required for lipid droplet targeting of some proteins, suggesting a possible direct interaction between COPI and lipid droplets. Here, we find that COPI coat components can bud 60-nm triacylglycerol nanodroplets from artificial lipid droplet (LD) interfaces. This budding decreases phospholipid packing of the monolayer decorating the mother LD. As a result, hydrophobic triacylglycerol molecules become more exposed to the aqueous environment, increasing LD surface tension. In vivo, this surface tension increase may prime lipid droplets for reactions with neighboring proteins or membranes. It provides a mechanism fundamentally different from transport vesicle formation by COPI, likely responsible for the diverse lipid droplet phenotypes associated with depletion of COPI subunits.