Nearly all cell types have the ability to store excess energy as triglycerides in specialized organelles called lipid droplets. The formation and degradation of lipid droplets is governed by a diverse set of enzymes and lipid droplet-associated proteins. One of the lipid droplet-associated proteins is Hypoxia Inducible Lipid Droplet Associated (HILPDA). HILPDA was originally discovered in a screen to identify novel hypoxia-inducible proteins. Apart from hypoxia, levels of HILPDA are induced by fatty acids and adrenergic agonists. HILPDA is a small protein of 63 amino acids in humans and 64 amino acids in mice. Inside cells, HILPDA is located in the endoplasmic reticulum and around lipid droplets. Gain- and loss-of-function experiments have demonstrated that HILPDA promotes lipid storage in hepatocytes, macrophages and cancer cells. HILPDA increases lipid droplet accumulation at least partly by inhibiting triglyceride hydrolysis via ATGL and stimulating triglyceride synthesis via DGAT1. Overall, HILPDA is a novel regulatory signal that adjusts triglyceride storage and the intracellular availability of fatty acids to the external fatty acid supply and the capacity for oxidation.

中文翻译：

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通过缺氧诱导的脂质滴相关的HILPDA调节脂质滴稳态。

几乎所有类型的细胞都有能力将多余的能量以甘油三酸酯的形式存储在称为脂质滴的特殊细胞器中。脂质滴的形成和降解受多种酶和脂质滴相关蛋白的控制。与脂质滴相关的蛋白质之一是低氧诱导性脂质滴相关（HILPDA）。HILPDA最初是在屏幕上发现的，可识别新型的缺氧诱导蛋白。除缺氧外，脂肪酸和肾上腺素能激动剂可诱导HILPDA的水平。HILPDA是一种小蛋白质，在人类中为63个氨基酸，在小鼠中为64个氨基酸。在细胞内部，HILPDA位于内质网和脂质滴周围。功能获得和丧失的实验表明，HILPDA促进脂质在肝细胞，巨噬细胞和癌细胞中的储存。HILPDA至少部分地通过通过ATGL抑制甘油三酸酯水解并通过DGAT1刺激甘油三酸酯合成来增加脂质滴的积累。总体而言，HILPDA是一种新颖的调节信号，可调节甘油三酸酯的储存以及脂肪酸在细胞内对外部脂肪酸供应的供应和氧化能力。