Dissection of autophagosome formation using Apg5-deficient mouse embryonic stem cells.
Dissection of autophagosome formation using Apg5-deficient mouse embryonic stem cells.
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DOI：
10.1083/jcb.152.4.657
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发表时间：
2001-02-19
期刊：
影响因子：
--
通讯作者：
Yoshimori T
中科院分区：
文献类型：
--
作者：
Mizushima N;Yamamoto A;Hatano M;Kobayashi Y;Kabeya Y;Suzuki K;Tokuhisa T;Ohsumi Y;Yoshimori T
在巨噬过程中，细胞质成分通过杯状隔离膜闭合形成的自噬体传递给溶酶体降解。然而，人们对隔离膜是如何形成的知之甚少。我们最近在酵母中发现了一种新的泛素样系统，Apg12-Apg5偶联系统，对自噬至关重要。本研究表明，小鼠Apg12-Apg5偶联物定位于小鼠胚胎干细胞的分离膜上。使用绿色荧光蛋白标记的Apg5，我们发现杯状隔离膜是由一个小的新月形隔室发育而成的。Apg5在整个延伸过程中定位在隔离膜上。为了研究Apg5的作用，我们制造了Apg5缺陷的胚胎干细胞，这些干细胞在自噬体形成方面存在缺陷。Apg5与Apg12的共价修饰不是其膜靶向所必需的，但对于Apg5参与分离膜的延伸是必不可少的。我们还发现，Apg12-Apg5是将哺乳动物Aut7/ ap8同源物LC3靶向到分离膜上所必需的。这些结果表明，Apg12-Apg5偶联物在分离膜发育中起重要作用。
In macroautophagy, cytoplasmic components are delivered to lysosomes for degradation via autophagosomes that are formed by closure of cup-shaped isolation membranes. However, how the isolation membranes are formed is poorly understood. We recently found in yeast that a novel ubiquitin-like system, the Apg12-Apg5 conjugation system, is essential for autophagy. Here we show that mouse Apg12-Apg5 conjugate localizes to the isolation membranes in mouse embryonic stem cells. Using green fluorescent protein–tagged Apg5, we revealed that the cup-shaped isolation membrane is developed from a small crescent-shaped compartment. Apg5 localizes on the isolation membrane throughout its elongation process. To examine the role of Apg5, we generated Apg5-deficient embryonic stem cells, which showed defects in autophagosome formation. The covalent modification of Apg5 with Apg12 is not required for its membrane targeting, but is essential for involvement of Apg5 in elongation of the isolation membranes. We also show that Apg12-Apg5 is required for targeting of a mammalian Aut7/Apg8 homologue, LC3, to the isolation membranes. These results suggest that the Apg12-Apg5 conjugate plays essential roles in isolation membrane development.
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影响因子：
11.4
作者：
Mizushima, N;Noda, T;Ohsumi, Y
通讯作者：
Ohsumi, Y
DOI：
10.1007/bf00493232
发表时间：
1980-01-01
期刊：
HISTOCHEMISTRY
影响因子：
--
作者：
HIRSIMAKI, P;REUNANEN, H
通讯作者：
REUNANEN, H
影响因子：
15.9
作者：
Hatano, M;Aoki, T;Tokuhisa, T
通讯作者：
Tokuhisa, T
影响因子：
3.3
作者：
Kim, J;Dalton, VM;Klionsky, DJ
通讯作者：
Klionsky, DJ
影响因子：
3.3
作者：
George, MD;Baba, M;Klionsky, DJ
通讯作者：
Klionsky, DJ