LC3, a microtubule-associated protein1A/B light chain3, is involved in cytoplasmic lipid droplet formation
LC3, a microtubule-associated protein1A/B light chain3, is involved in cytoplasmic lipid droplet formation
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DOI：
10.1016/j.bbrc.2010.01.121
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发表时间：
2010-03-05
影响因子：
3.1
通讯作者：
Uchiyama, Yasuo
中科院分区：
文献类型：
--
作者：
Shibata, Masahiro;Yoshimura, Kentaro;Uchiyama, Yasuo
细胞质脂滴（LD）是一种以中性脂质为核心、磷脂为单层的细胞器。LD被认为是在内质网（ER）膜的两个小叶之间产生的，并发挥各种作用，如高效储能。然而，它仍然在很大程度上是未知的LD是如何产生的，并在细胞质中生长。我们以前已经表明，在肝细胞和心肌细胞中LD的形成所涉及的Atg共轭系统，是必不可少的自噬体的形成。我们在这里显示，LC3本身是参与LD的形成，通过使用RNA干扰（RNAi）。检测的所有培养细胞系，其中LC3的表达被RNAi抑制，显示LD形成减少。三酰甘油，LD的主要成分，在LC3 mRNA敲低细胞以及在对照细胞中合成和降解。有趣的是，敲低细胞中大量蛋白质降解的潜力在对照细胞中也是明显的。这些研究结果表明，LC 3参与LD的形成，而不管大量降解，LC 3在细胞自噬和脂质代谢介导的稳态中具有两个关键作用。(C)2010年爱思唯尔公司All rights reserved.
The cytoplasmic lipid droplet (LD) is one of organelles that has a neutral lipid core with a single phospholipid layer. LDs are believed to be generated between the two leaflets of the endoplasmic reticulum (ER) membrane and to play various roles, such as high effective energy storage. However, it remains largely unknown how LDs are generated and grow in the cytoplasm. We have previously shown that the Atg conjugation system that is essential for autophagosome formation is involved in LD formation in hepatocytes and cardiac myocytes. We show here that LC3 itself is involved in LD formation by using RNA interference (RNAi). All cultured cell lines examined, in which the expression of LC3 was suppressed by RNAi, showed reduced LD formation. Triacylglycerol, a major component of LDs, was synthesized and degraded in LC3 mRNA-knockdown cells as well as in control cells. Interestingly, potential of the bulk protein degradation in the knockdown-cells was also evident in the control cells. These findings indicate that LC3 is involved in the LD formation regardless of the bulk degradation, and that LC3 has two pivotal roles in cellular homeostasis mediated by autophagy and lipid metabolism. (C) 2010 Elsevier Inc. All rights reserved.