Starvation triggers the delivery of the endoplasmic reticulum to the vacuole via autophagy in yeast
Starvation triggers the delivery of the endoplasmic reticulum to the vacuole via autophagy in yeast
复制标题
DOI：
10.1111/j.1600-0854.2004.00245.x
复制
发表时间：
2005-01-01
期刊：
影响因子：
4.5
通讯作者：
Ohsumi, Y
中科院分区：
文献类型：
--
作者：
Hamasaki, M;Noda, T;Ohsumi, Y
自噬是真核细胞克服营养挑战环境所必需的一种生存机制。当自噬被触发时，细胞非选择性地降解，吞噬均匀分布在细胞质中的胞浆蛋白和游离核糖体。由此产生的游离氨基酸池用于维持对生存至关重要的过程。在这里，我们描述了饥饿条件下内质网(ER)的自噬降解以及胞浆蛋白的降解。在相同条件下，高尔基体膜蛋白未被自噬小体吞噬，表明自噬小体摄取内质网是一种特异性事件。虽然内质网存在于相互连接的网络结构中，并且主要位于细胞核周围和质膜之下，但大多数自噬小体吞噬了内质网。自噬摄取内质网的程度与可溶性胞浆蛋白的摄取程度几乎相同。这一现象可以用几乎所有自噬体内出现的碎裂的内质网膜结构来解释。此外，这一过程需要内质网的动力：自噬小体以肌动蛋白依赖的方式摄取内质网。
Autophagy is a survival mechanism necessary for eukaryotic cells to overcome nutritionally challenged environments. When autophagy is triggered, cells degrade nonselectively engulfed cytosolic proteins and free ribosomes that are evenly distributed throughout the cytoplasm. The resulting pool of free amino acids is used to sustain processes crucial for survival. Here we characterize an autophagic degradation of the endoplasmic reticulum (ER) under starvation conditions in addition to cytosolic protein degradation. Golgi membrane protein was not engulfed by the autophagosome under the same conditions, indicating that the uptake of ER by autophagosome was the specific event. Although the ER exists in a network structure that is mutually connected and resides predominantly around the nucleus and beneath the plasma membrane, most of autophagosome engulfed ER. The extent of the ER uptake by autophagy was nearly identical to that of the soluble cytosolic proteins. This phenomenon was explained by the appearance of fragmented ER membrane structures in almost all autophagosomes. Furthermore, ER dynamism is required for this process: ER uptake by autophagosomes occurs in an actin-dependent manner.