摘要
Lipid droplets (LDs) serve as specialized cytoplasmic organelles that harbor energy-rich lipids for long-term storage and may be mobilized as nutrient sources during extended starvation. How cells coordinate LD biogenesis and utilization in response to fluctuations in nutrient availability remains poorly understood. Here, we discuss our recent work revealing how yeast spatially organize LD budding at organelle contacts formed between the endoplasmic reticulum and yeast vacuole/lysosome (sites known as nucleus-vacuole junctions [NVJs]). During times of imminent nutrient exhaustion, we observe blooms of stress-induced LDs surrounding the NVJ and find that this LD clustering is regulated by NVJ-resident protein Mdm1. We also discuss several emerging studies revealing specific proteins that demarcate a subpopulation of NVJ-associated LDs. Collectively, these studies reveal a previously unappreciated role for the spatial compartmentalization of LDs at organelle contacts and highlight an important role for interorganellar cross talk in LD dynamics under times of nutritional stress.
摘要译文
脂质液滴（LD）用作特殊的细胞质细胞器，其具有富含能量的脂质用于长期储存，并且可以在长期饥饿期间作为营养源动员。细胞如何协调LD生物合成和利用以响应养分可用性的波动仍然知之甚少。在这里，我们讨论我们最近的工作，揭示酵母如何在内质网和酵母液泡/溶酶体（称为核 - 液泡连接点[NVJs]之间）形成的细胞器接触处空间组织LD萌芽。在即将营养耗尽的时期，我们观察到NVJ周围的应激诱导的LD的大量繁殖，并发现该LD聚类受NVJ驻留蛋白Mdm1的调节。我们还讨论了几项新兴研究，揭示了划分NVJ相关LD亚群的特定蛋白质。总的来说，这些研究揭示了在细胞器接触处LD的空间区室化的先前未被认可的作用，并突出了在营养应激时期LD动力学中的interorganellar串扰的重要作用。
W. Mike Henne[1]; Hanaa Hariri[1]. Endoplasmic Reticulum-Vacuole Contact Sites “Bloom” With Stress-Induced Lipid Droplets[J]. Contact, 2018,1