Department of Pathology and Cell Biology, Columbia University, New York, NY, 10032 USA.
HHMI and Dept. of Neuroscience, University of Wisconsin, Madison, WI, 53705 USA.
Front Biosci (Landmark Ed). 2018 Mar 1;23(8):1552-1563. doi: 10.2741/4660.
Lipid droplets (LDs) have well-established functions as sites for lipid storage and energy mobilization to meet the metabolic demands of cells. However, recent studies have expanded the roles of LDs to protein quality control. Lipophagy, or LD degradation by autophagy, plays a vital role not only in the mobilization of free fatty acids (FFAs) and lipid homeostasis at LDs, but also in the adaptation of cells to certain forms of stress including lipid imbalance. Recent studies have provided new mechanistic insights about the diverse types of lipophagy, in particular microlipophagy. This review summarizes key findings about the mechanisms and functions of lipophagy and highlights a novel function of LD microlipophagy as a mechanism to maintain endoplasmic reticulum (ER) proteostasis under conditions of lipid imbalance.
脂滴 (LDs) 作为脂质储存和能量动员的场所，具有明确的功能，以满足细胞的代谢需求。然而，最近的研究已经扩展了 LDs 在蛋白质质量控制方面的作用。脂噬作用，即自噬作用引起的 LD 降解，不仅在游离脂肪酸 (FFAs) 的动员和 LD 中的脂质动态平衡中起着至关重要的作用，而且在细胞对某些形式的应激包括脂质失衡的适应中也起着至关重要的作用。最近的研究提供了关于不同类型脂噬作用的新的机制见解，特别是微脂噬作用。本综述总结了关于脂噬作用的机制和功能的关键发现，并强调了 LD 微脂噬作用作为维持内质网 (ER) 在脂质失衡条件下的蛋白质稳态的一种机制的新功能。
