Nucleus-vacuole junctions and piecemeal microautophagy of the nucleus in S-cerevisiae

被引：105

作者：

Kvam, Erik ^{[1
]}

Goldfarb, David S. ^{[1
]}

机构：

[1] Univ Rochester, Dept Biol, Rochester, NY 14627 USA

来源：

AUTOPHAGY | 2007年 / 3卷 / 02期

基金：

美国国家卫生研究院; 美国国家科学基金会;

关键词：

nuclear envelope; vacuole; microautophagy;

D O I：

10.4161/auto.3586

中图分类号：

Q2 [细胞生物学];

学科分类号：

071009 ; 090102 ;

摘要：

Various modes of autophogy conspire to degrade virtually every compartment of the eukaryotic cell. In Saccharomyces cerevisiae, a process called "piecemeal microautophogy of the nucleus" (PMN) even pinches off and degrades nonessential portions of the nucleus. PMN is a constitutive process induced to high levels by starvation or rapamycin, an inhibitor of TOR kinase. PMN occurs at nucleus-vacuole (NV) junctions, which are Velcro-like patches formed by interactions between the vacuole membrane protein Vac8p and the outer-nuclear-membrane protein Nvj1p. In response to nutrient depletion, Nvj1p increasingly binds and sequesters two proteins with roles in lipid metabolism, Osh1p and Tsc13p. Tsc13p is required for the normal biogenesis of PMN vesicles. The sequestration of Osh1p by Nvj1p likely serves to negatively regulate the trafficking of tryptophan permease(s) to the plasma membrane. Thus, NV junctions and PMN orchestrate novel and sophisticated responses to nutrient limitation.

引用

页码：85 / 92

页数：8

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