PtdIns4P restriction by hydrolase SAC1 decides specific fusion of autophagosomes with lysosomes
PtdIns4P restriction by hydrolase SAC1 decides specific fusion of autophagosomes with lysosomes
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水解酶 SAC1 的 PtdIns4P 限制决定自噬体与溶酶体的特异性融合
DOI：
10.1080/15548627.2020.1796321
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发表时间：
2021
期刊：
影响因子：
13.3
通讯作者：
Lu Kefeng
中科院分区：
文献类型：
--
作者：
Zhang Hongjun;Zhou Jiao;Xiao Peng;Lin Yong;Gong Xin;Liu Shiyan;Xu Qingjia;Wang Minjin;Ren Haiyan;Lu Mengji;Wang Yuan;Zhu Jing;Xie Zhiping;Li Huihui;Lu Kefeng
自噬体的生物发生是大自噬/自噬的早期步骤，并且需要主要从ER-高尔基体来源的前体囊泡获得膜。成熟的自噬体与溶酶体融合进行最终降解。然而，如何确定这种选择性融合仍然是难以捉摸的。在此，我们通过高通量筛选在酵母中鉴定了Sac 1，表明其通过PtdIns 4P磷酸酶活性对自噬体-溶酶体融合至关重要。Sac 1缺陷导致PtdIns 4P在早期高尔基体的急剧增加和PtdIns 4P异常掺入Atg 9囊泡和自噬体中，这导致无法招募SNARE蛋白与空泡融合。Sac 1在自噬中的功能从酵母到哺乳动物细胞是高度保守的。因此，我们的工作表明，正确的上游脂质掺入是重要的下游融合步骤的自噬和Sac 1发挥了关键和古老的作用，在这种监督脂质整合。缩写：Ape 1：氨肽酶I; ATG：自噬相关; EBSS：厄尔平衡盐溶液; ER：内质网; ERGIC：高尔基体和ER-高尔基中间室; HOPS：同型融合和蛋白分选复合物; MAP1LC 3/LC 3：微管相关蛋白1轻链3; PtdIns 3 P：磷脂酰肌醇-3-磷酸; PtdIns 4K：磷酸肌醇-4-激酶; PtdIns 4P：磷脂酰肌醇-4-磷酸; SD-N：氮饥饿培养基; SNARE：可溶性N-乙酰胺敏感因子附着蛋白受体
Biogenesis of autophagosomes is the early step of macroautophagy/autophagy and requires membrane acquisition mainly from ER-Golgi-sourced precursor vesicles. Matured autophagosomes fuse with lysosomes for final degradation. However, how this selective fusion is determined remains elusive. Here, we identified Sac1 by a high throughput screen inSaccharomyces cerevisiaeto show it was critical for autophagosome-lysosome fusion through its PtdIns4P phosphatase activity. Sac1 deficiency caused a dramatic increase of PtdIns4P at early Golgi apparatus and abnormal incorporation of PtdIns4P into Atg9 vesicles and autophagosomes, which caused failure to recruit SNARE proteins for autophagosome fusion with vacuoles. Sac1 function in autophagy was highly conserved from yeast to mammalian cells. Our work thus suggested that correct upstream lipid incorporation was important for downstream fusion step of autophagy and that Sac1 played a critical and ancient role in this surveillance of lipid integration.Abbreviations:Ape1: aminopeptidase Ι; ATG: autophagy related; EBSS: Earle’s balanced salt solution; ER: endoplasmic reticulum; ERGIC: Golgi apparatus and ER-Golgi intermediate compartment; HOPS: homotypic fusion and protein sorting complex; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; PtdIns3P: phosphatidylinositol-3-phosphate; PtdIns4K: phosphoinositide-4-kinase; PtdIns4P: phosphatidylinositol-4-phosphate; SD-N: nitrogen starvation medium; SNARE: soluble N-ethylamide-sensitive factor attachment protein receptor