Cvt18/Gsa12 is required for cytoplasm-to-vacuole transport, pexophagy, and autophagy in Saccharomyces cerevisiae and Pichia pastoris
Cvt18/Gsa12 is required for cytoplasm-to-vacuole transport, pexophagy, and autophagy in Saccharomyces cerevisiae and Pichia pastoris
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DOI：
10.1091/mbc.12.12.3821
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发表时间：
2001-12-01
影响因子：
3.3
通讯作者：
Klionsky, DJ
中科院分区：
文献类型：
--
作者：
Guan, J;Stromhaug, PE;Klionsky, DJ
真核细胞具有通过选择性和非选择性的微观和宏观自噬模式降解蛋白质和细胞器的能力。此外，存在组成性和调节性形式的自噬。例如，pexophagy是一种通过自噬调节过氧化物酶体降解的选择性过程。我们的研究表明，自噬的不同途径有许多共同的分子事件。在这篇文章中，我们已经确定了自噬基因家族中的一个新成员。巴斯德毕赤酵母GSA 12及其酿酒酵母（Saccharomyces cerevisiae）对应物CVT 18编码具有两个WD 40结构域的可溶性蛋白。我们已经表明，这些蛋白质是巴斯德毕赤酵母中的噬菌体和自噬以及S.啤酒。在巴斯德毕赤酵母中，Gsa 12似乎是早期食粪所必需的。也就是说，在gsa12突变体中不发生液泡的退化或液泡臂的延伸以吞噬过氧化物酶体。与其在液泡吞噬中的作用一致，我们发现这种胞质蛋白也定位于液泡表面。类似地，Cvt18显示亚细胞定位，将其与细胞质至液泡递送途径所需的特征蛋白质区分开来。
Eukaryotic cells have the ability to degrade proteins and organelles by selective and nonselective modes of micro- and macroautophagy. In addition, there exist both constitutive and regulated forms of autophagy. For example, pexophagy is a selective process for the regulated degradation of peroxisomes by autophagy. Our studies have shown that the differing pathways of autophagy have many molecular events in common. In this article, we have identified a new member in the family of autophagy genes. GSA12 in Pichia pastoris and its Saccharomyces cerevisiae counterpart, CVT18, encode a soluble protein with two WD40 domains. We have shown that these proteins are required for pexophagy and autophagy in P. pastoris and the Cvt pathway, autophagy, and pexophagy in S. cerevisiae. In P. pastoris, Gsa12 appears to be required for an early event in pexophagy. That is, the involution of the vacuole or extension of vacuole arms to engulf the peroxisomes does not occur in the gsa12 mutant. Consistent with its role in vacuole engulfment, we have found that this cytosolic protein is also localized to the vacuole surface. Similarly, Cvt18 displays a subcellular localization that distinguishes it from the characterized proteins required for cytoplasm-to-vacuole delivery pathways.