The actin cytoskeleton is required for selective types of autophagy, but not nonspecific autophagy, in the yeast Saccharomyces cerevisiae
The actin cytoskeleton is required for selective types of autophagy, but not nonspecific autophagy, in the yeast Saccharomyces cerevisiae
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DOI：
10.1091/mbc.e05-07-0629
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发表时间：
2005-12-01
影响因子：
3.3
通讯作者：
Klionsky, DJ
中科院分区：
文献类型：
--
作者：
Reggiori, F;Monastyrska, L;Klionsky, DJ
自噬是一种发生在所有真核细胞中的分解代谢多任务运输途径。在饥饿期间，细胞质成分被随机隔离到称为自噬体的巨大双膜囊泡中，并被输送到溶酶体/液泡中，并在那里被破坏。细胞能够根据其需要调节自噬，并且在某些情况下，异常蛋白质聚集体、细胞器和细菌等货物可以选择性地、排他性地掺入自噬体中。例如，在酿酒酵母中，双膜囊泡用于将 Ape1 蛋白酶转运到液泡中，或用于消除多余的过氧化物酶体。在本研究中，我们揭示了在这种生物体中，肌动蛋白在这两种类型的选择性自噬中发挥作用，但在非选择性自噬过程中不起作用。特别是，我们发现前体 Ape1 没有被正确地招募到 PAS（双膜囊泡生物发生的假定位点），并且多余的过氧化物酶体在条件肌动蛋白突变体中不会被降解。这些现象与 Atg9 从线粒体到 PAS 的运输缺陷相关。
Autophagy is a catabolic multitask transport route that takes place in all eukaryotic cells. During starvation, cytoplasmic components are randomly sequestered into huge double-membrane vesicles called autophagosomes and delivered into the lysosome/vacuole where they are destroyed. Cells are able to modulate autophagy in response to their needs, and under certain circumstances, cargoes such as aberrant protein aggregates, organelles and bacteria can be selectively and exclusively incorporated into autophagosomes. In the yeast Saccharomyces cerevisiae, for example, double-membrane vesicles are used to transport the Ape1 protease into the vacuole, or for the elimination of superfluous peroxisomes. In the present study we reveal that in this organism, actin plays a role in these two types of selective autophagy but not in the nonselective, bulk process. in particular, we show that precursor Ape1 is not correctly recruited to the PAS, the putative site of double-membrane vesicle biogenesis, and superfluous peroxisomes are not degraded in a conditional actin mutant. These phenomena correlate with a defect in Atg9 trafficking from the mitochondria to the PAS.