ATG14 plays a critical role in hepatic lipid droplet homeostasis.
ATG14 plays a critical role in hepatic lipid droplet homeostasis.
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DOI：
10.1016/j.metabol.2023.155693
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发表时间：
2023-09
期刊：
影响因子：
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通讯作者：
Menghao Huang;Yang Zhang;Jimin Park;Kushan Chowdhury;Jiazhi Xu;Alex Lu;Lu Wang;Wenjun Zhang;B. Ekser;Liqing Yu;X. C. Dong
中科院分区：
文献类型：
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作者：
Menghao Huang;Yang Zhang;Jimin Park;Kushan Chowdhury;Jiazhi Xu;Alex Lu;Lu Wang;Wenjun Zhang;B. Ekser;Liqing Yu;X. C. Dong
自噬相关蛋白14（Autophagy-related 14，ATG 14）是自噬的关键调节因子。ATG 14也定位于脂滴，然而，ATG 14对脂滴的功能尚不清楚。本研究旨在阐明ATG 14在脂滴稳态中的作用。方法采用荧光成像技术分析ATG 14基因敲低和过表达肝细胞中ATG 14在脂滴代谢中的功能缺失和功能获得。通过缺失或位点特异性诱变来分析参与ATG 14靶向脂滴的特异性结构域。通过免疫共沉淀分析ATG 14相互作用蛋白。ATG 14对脂肪分解的影响进行了分析，在人肝细胞和小鼠肝脏缺乏ATG 14，比较基因识别-58（CGI-58），或both.ResultsOur数据显示，ATG 14是丰富的肝细胞中的脂滴。突变分析显示，ATG 14的Barkor/ATG 14自噬体靶向序列（BATS）结构域负责ATG 14定位于脂滴。免疫共沉淀分析表明，ATG 14与脂肪甘油三酯脂肪酶（ATGL）和CGI-58相互作用。此外，ATG 14还增强了ATGL和CGI-58之间的相互作用。体外脂解分析表明，ATG 14缺乏显着降低甘油三酯hydrolyzation.ConclusionsOur数据表明，ATG 14可以直接增强脂滴通过与ATGL和CGI-58的相互作用分解。
Background & aimsAutophagy-related 14 (ATG14) is a key regulator of autophagy. ATG14 is also localized to lipid droplet; however, the function of ATG14 on lipid droplet remains unclear. In this study, we aimed to elucidate the role of ATG14 in lipid droplet homeostasis.MethodsATG14 loss-of-function and gain-of-function in lipid droplet metabolism were analyzed by fluorescence imaging in ATG14 knockdown or overexpression hepatocytes. Specific domains involved in the ATG14 targeting to lipid droplets were analyzed by deletion or site-specific mutagenesis. ATG14-interacting proteins were analyzed by co-immunoprecipitation. The effect of ATG14 on lipolysis was analyzed in human hepatocytes and mouse livers that were deficient in ATG14, comparative gene identification-58 (CGI-58), or both.ResultsOur data show that ATG14 is enriched on lipid droplets in hepatocytes. Mutagenesis analysis reveals that the Barkor/ATG14 autophagosome targeting sequence (BATS) domain of ATG14 is responsible for the ATG14 localization to lipid droplets. Co-immunoprecipitation analysis illustrates that ATG14 interacts with adipose triglyceride lipase (ATGL) and CGI-58. Moreover, ATG14 also enhances the interaction between ATGL and CGI-58. In vitro lipolysis analysis demonstrates that ATG14 deficiency remarkably decreases triglyceride hydrolysis.ConclusionsOur data suggest that ATG14 can directly enhance lipid droplet breakdown through interactions with ATGL and CGI-58.