Proteasome synthesis and assembly are required for survival during stationary phase
Proteasome synthesis and assembly are required for survival during stationary phase
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DOI：
10.1016/j.freeradbiomed.2004.05.025
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发表时间：
2004-09-15
影响因子：
7.4
通讯作者：
Keller, JN
中科院分区：
文献类型：
--
作者：
Chen, QH;Thorpe, J;Keller, JN
我们研究了20 S蛋白酶体稳态，蛋白质氧化，和细胞活力发生在静止期或酵母老化的时序模型的改变。本报告中的数据表明，蛋白酶体亚基的表达增加，蛋白酶体的组合物被改变，和个人的蛋白酶体蛋白水解活性的水平升高，在稳定期诱导的老化在酿酒酵母。尽管有这样的改变，蛋白酶体介导的蛋白质降解和蛋白质氧化的显着增加进行性损失中观察到的细胞保持在稳定期条件下。UMP 1，20 S蛋白酶体生物合成所必需的基因的缺失，在正常生长条件下对细胞活力没有影响，但损害了细胞在稳定期条件下生存的能力。在稳定期，氧化蛋白的水平增加得更快，并在突变体中缺乏UMP1比野生型细胞更高的水平。两者合计，这些数据暗示了蛋白酶体合成和改变的20 S蛋白酶体组合物在稳定期期间维持活力的作用，并表明即使有这些修饰，蛋白酶体介导的蛋白质降解的逐渐丧失也发生在稳定期诱导的衰老期间。这些数据还表明，受损的蛋白酶体介导的蛋白质降解在真核细胞衰老过程中观察到的蛋白质氧化和细胞死亡增加中的作用。(C)2004年由Elsevier Inc.出版
We examined the alterations in 20S proteasome homeostasis, protein oxidation, and cell viability that occur during the stationary phase or chronological model of yeast aging. Data in this report demonstrate that proteasome subunit expression is increased, proteasome composition is altered, and levels of individual proteasome proteolytic activities are elevated during stationary phase-induced aging in Saccharomyces cerevisiae. Despite such alterations, a progressive loss of proteasome-mediated protein degradation and a significant increase in protein oxidation were observed in cells maintained under stationary phase conditions. Deletion of UMP1, a gene necessary for 20S proteasome biogenesis, had no effect on cellular viability under normal growth conditions, but impaired the ability of cells to survive under stationary phase conditions. During stationary phase, the levels of oxidized protein increased more rapidly and to higher levels in the mutant lacking UMP1 than in the wild-type cells. Taken together, these data implicate a role for proteasome synthesis and altered 20S proteasome composition in maintaining viability during stationary phase, and demonstrate that even with these modifications a gradual loss of proteasome-mediated protein degradation occurs during stationary phase-induced aging. These data also suggest a role for impaired proteasome-mediated protein degradation in increased protein oxidation and cell death observed during the aging of eukaryotic cells. (C) 2004 Published by Elsevier Inc.