The requirements of yeast Hsp70 of SSA family for the ubiquitin-dependent degradation of short-lived and abnormal proteins.
The requirements of yeast Hsp70 of SSA family for the ubiquitin-dependent degradation of short-lived and abnormal proteins.
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DOI：
10.1016/j.bbrc.2016.05.046
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发表时间：
2016-06-17
影响因子：
3.1
通讯作者：
Goldberg AL
中科院分区：
文献类型：
--
作者：
Lee do H;Sherman MY;Goldberg AL
SSA家族的胞质Hsp 70，特别是Ssa 1 p，参与酵母中多种错误折叠蛋白的降解。然而，其他Ssa蛋白在这一过程中的重要性尚不清楚。为了阐明单个Ssa蛋白在蛋白水解中的作用，我们测量了缺乏不同Ssa蛋白的突变体中各种细胞蛋白的分解。在缺乏Ssa 1 p和Ssa 2 p的突变体中，短寿命蛋白质的蛋白酶体降解减少，这不能通过Ssa 1 p的过表达完全恢复。相比之下，稳定的细胞蛋白的降解不需要Ssa蛋白。Ssa蛋白的失活抑制了胞质模型底物（Ub-P-β-gal和R-β-gal）的降解及其泛素化。此外，Ssa 1 p和辅助分子伴侣Ydj 1 p是不可缺少的细胞内降解的突变分泌蛋白，Siiyama变体的人抗胰蛋白酶。我们的研究结果表明，Ssa 1 p和Ssa 2 p是必不可少的短寿命蛋白的泛素依赖性降解和Ssa蛋白和辅分子伴侣的要求有很大的不同，这取决于构象和折叠状态的基板。
Cytoplasmic Hsp70s of SSA family, especially Ssa1p, are involved in the degradation of a variety of misfolded proteins in yeast. However the importance of other Ssa proteins in this process is unclear. To clarify the role(s) of individual Ssa proteins in proteolysis, we measured the breakdown of various cell proteins in mutants lacking different Ssa proteins. In mutants lacking Ssa1p and Ssa2p, the proteasomal degradation of short-lived proteins was reduced, which was not restored fully by the over-expression of Ssa1p. By contrast, the degradation of stable cellular proteins did not require Ssa proteins. The degradation of the cytosolic model substrates (Ub-P-β-gal and R-β-gal) and their ubiquitylation were inhibited by the inactivation of Ssa proteins. In addition, Ssa1p and the co-chaperone Ydj1p are indispensable for the intracellular degradation of a mutant secretory protein, Siiyama variant of human antitrypsin. Our findings indicate that both Ssa1p and Ssa2p are essential for the ubiquitin-dependent degradation of short-lived proteins and the requirements of Ssa proteins and the co-chaperones widely vary depending on the conformations and folding status of the substrates.
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表达SSA1，SSA2，SSA3或SSA4的酵母细胞的全局转录本和表型分析是胞质HSP70-SSA伴侣活性的唯一来源。
影响因子：
4.4
作者：
Hasin N;Cusack SA;Ali SS;Fitzpatrick DA;Jones GW
通讯作者：
Jones GW
将果糖-1, 6-双磷酸酶导入 Vid 囊泡需要热休克蛋白 Ssa2p。
DOI：
10.1083/jcb.150.1.65
发表时间：
2000-07-10
期刊：
The Journal of cell biology
影响因子：
--
作者：
Brown CR;McCann JA;Chiang HL
通讯作者：
Chiang HL
影响因子：
3.3
作者：
Zhang, YM;Nijbroek, G;Brodsky, JL
通讯作者：
Brodsky, JL
影响因子：
21.3
作者：
Hwang, Cheol-Sang;Shemorry, Anna;Auerbach, Daniel;Varshavsky, Alexander
通讯作者：
Varshavsky, Alexander
影响因子：
19
作者：
Kaushik S;Cuervo AM
通讯作者：
Cuervo AM