Kumar Akhil, Yadav Surabhi, Choudhary Vineet
Department of Biotechnology, All India Institute of Medical Sciences (AIIMS), New Delhi, India.
Front Cell Dev Biol. 2024 Oct 3;12:1483902. doi: 10.3389/fcell.2024.1483902. eCollection 2024.
Lipid droplets (LDs) are evolutionarily conserved dynamic organelles that play an important role in cellular physiology. Growing evidence suggests that LD biogenesis occurs at discrete endoplasmic reticulum (ER) subdomains demarcated by the lipodystrophy protein, Seipin, lack of which impairs adipogenesis. However, the mechanisms of how these domains are selected is not completely known. These ER sites undergo ordered assembly of proteins and lipids to initiate LD biogenesis and facilitate establishment of ER-LD contact sites, a prerequisite for proper growth and maturation of droplets. LDs retain both physical and functional association with the ER throughout their lifecycle to facilitate bi-directional communication, such as exchange of proteins and lipids between the two organelles at these ER-LD contact sites. In recent years several molecular tethers have been identified that bridge ER and LDs together including few proteins that are found exclusively at these ER-LD contact interface. Here, we discuss recent advances in understanding the role of factors that ensure functionality of ER-LD contact site machinery for LD homeostasis.
脂滴（LDs）是进化上保守的动态细胞器，在细胞生理学中发挥重要作用。越来越多的证据表明，脂滴生物发生发生在由脂肪代谢障碍蛋白Seipin划定的离散内质网（ER）亚结构域，缺乏该蛋白会损害脂肪生成。然而，这些结构域如何被选择的机制尚不完全清楚。这些内质网位点经历蛋白质和脂质的有序组装，以启动脂滴生物发生并促进内质网 - 脂滴接触位点的建立，这是脂滴正常生长和成熟的先决条件。脂滴在其整个生命周期中都与内质网保持物理和功能上的关联，以促进双向通讯，例如在这些内质网 - 脂滴接触位点，两个细胞器之间进行蛋白质和脂质的交换。近年来，已经鉴定出几种分子连接物，它们将内质网和脂滴连接在一起，其中包括一些仅在这些内质网 - 脂滴接触界面发现的蛋白质。在这里，我们讨论了在理解确保内质网 - 脂滴接触位点机制对脂滴稳态功能的因素方面的最新进展。
