Triglyceride lipolysis triggers liquid crystalline phases in lipid droplets and alters the LD proteome.

Autor: Rogers S; Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX., Gui L; Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX., Kovalenko A; Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX., Zoni V; Department of Biology, University of Fribourg, Fribourg, Switzerland., Carpentier M; Laboratoire de Physique de l'École Normale Supérieure, École normale supérieure, Université Paris Sciences et Lettres, Centre national de la recherche scientifique, Sorbonne Université, Université de Paris, Paris, France., Ramji K; Laboratoire de Physique de l'École Normale Supérieure, École normale supérieure, Université Paris Sciences et Lettres, Centre national de la recherche scientifique, Sorbonne Université, Université de Paris, Paris, France., Ben Mbarek K; Laboratoire de Physique de l'École Normale Supérieure, École normale supérieure, Université Paris Sciences et Lettres, Centre national de la recherche scientifique, Sorbonne Université, Université de Paris, Paris, France., Bacle A; Institute Jacques Monod, Centre national de la recherche scientifique, University of Paris, Paris, France., Fuchs P; Laboratoire des Biomolécules, Paris, France.; Université de Paris, UFR Sciences du Vivant, Paris, France., Campomanes P; Department of Biology, University of Fribourg, Fribourg, Switzerland., Reetz E; Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX., Speer NO; Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX., Reynolds E; Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX., Thiam AR; Laboratoire de Physique de l'École Normale Supérieure, École normale supérieure, Université Paris Sciences et Lettres, Centre national de la recherche scientifique, Sorbonne Université, Université de Paris, Paris, France., Vanni S; Department of Biology, University of Fribourg, Fribourg, Switzerland., Nicastro D; Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX., Henne WM; Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX.
Jazyk: angličtina
Zdroj: The Journal of cell biology [J Cell Biol] 2022 Nov 07; Vol. 221 (11). Date of Electronic Publication: 2022 Sep 16.
DOI: 10.1083/jcb.202205053
Abstrakt: Lipid droplets (LDs) are reservoirs for triglycerides (TGs) and sterol-esters (SEs), but how these lipids are organized within LDs and influence their proteome remain unclear. Using in situ cryo-electron tomography, we show that glucose restriction triggers lipid phase transitions within LDs generating liquid crystalline lattices inside them. Mechanistically this requires TG lipolysis, which decreases the LD's TG:SE ratio, promoting SE transition to a liquid crystalline phase. Molecular dynamics simulations reveal TG depletion promotes spontaneous TG and SE demixing in LDs, additionally altering the lipid packing of the PL monolayer surface. Fluorescence imaging and proteomics further reveal that liquid crystalline phases are associated with selective remodeling of the LD proteome. Some canonical LD proteins, including Erg6, relocalize to the ER network, whereas others remain LD-associated. Model peptide LiveDrop also redistributes from LDs to the ER, suggesting liquid crystalline phases influence ER-LD interorganelle transport. Our data suggests glucose restriction drives TG mobilization, which alters the phase properties of LD lipids and selectively remodels the LD proteome.
(© 2022 Rogers et al.)
Databáze: MEDLINE