Both the autophagy and proteasomal pathways facilitate the Ubp3p-dependent depletion of a subset of translation and RNA turnover factors during nitrogen starvation in Saccharomyces cerevisiae.
Both the autophagy and proteasomal pathways facilitate the Ubp3p-dependent depletion of a subset of translation and RNA turnover factors during nitrogen starvation in Saccharomyces cerevisiae.
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DOI：
10.1261/rna.045211.114
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发表时间：
2015-05
期刊：
影响因子：
--
通讯作者：
Bedwell DM
中科院分区：
文献类型：
--
作者：
Kelly SP;Bedwell DM
蛋白质周转是促进细胞适应不断变化的环境条件的重要调节机制。先前的研究表明，在氮饥饿期间，核糖体丰度会通过称为核糖体自噬的选择性自噬机制而减少，该机制依赖于去泛素化酶 Ubp3p。在这项研究中，我们询问酿酒酵母中各种翻译和 RNA 周转因子的丰度是否会随着氮饥饿的发生而减少。我们发现氮饥饿后测试的蛋白质丰度存在明显差异：（1）一些水平没有变化； (2) 其他蛋白质的减少与核糖体吞噬的动力学相似，(3) 一些蛋白质迅速耗尽。此外，不同的途径在氮饥饿时不同程度地降解各种蛋白质。翻译因子 eRF3 和 eIF4GI 以及脱帽增强子 Pat1p 需要完整的自噬途径才能耗尽。相比之下，去腺苷酸酶亚基 Pop2p 和脱帽酶 Dcp2p 通过蛋白酶体依赖性机制迅速耗尽。雷帕霉素还诱导蛋白酶体依赖性 Dcp2p 和 Pop2p 的消耗，表明 TOR1 途径影响该途径。与核糖体吞噬一样，eIF4GI、eRF3、Dcp2p 和 Pop2p 的消耗在不同程度上依赖于 Ubp3p。总之，我们的结果表明，在氮饥饿期间，自噬和蛋白酶体途径以 Ubp3p 依赖性方式降解不同的翻译和 RNA 周转因子。虽然核糖体吞噬被认为在营养限制期间介导稀缺资源的再利用，但我们的结果表明，特定蛋白质的选择性降解也可以促进基因表达转录后控制的更广泛的重编程。
Protein turnover is an important regulatory mechanism that facilitates cellular adaptation to changing environmental conditions. Previous studies have shown that ribosome abundance is reduced during nitrogen starvation by a selective autophagy mechanism termed ribophagy, which is dependent upon the deubiquitinase Ubp3p. In this study, we asked whether the abundance of various translation and RNA turnover factors are reduced following the onset of nitrogen starvation in Saccharomyces cerevisiae. We found distinct differences in the abundance of the proteins tested following nitrogen starvation: (1) The level of some did not change; (2) others were reduced with kinetics similar to ribophagy, and (3) a few proteins were rapidly depleted. Furthermore, different pathways differentially degraded the various proteins upon nitrogen starvation. The translation factors eRF3 and eIF4GI, and the decapping enhancer Pat1p, required an intact autophagy pathway for their depletion. In contrast, the deadenylase subunit Pop2p and the decapping enzyme Dcp2p were rapidly depleted by a proteasome-dependent mechanism. The proteasome-dependent depletion of Dcp2p and Pop2p was also induced by rapamycin, suggesting that the TOR1 pathway influences this pathway. Like ribophagy, depletion of eIF4GI, eRF3, Dcp2p, and Pop2p was dependent upon Ubp3p to varying extents. Together, our results suggest that the autophagy and proteasomal pathways degrade distinct translation and RNA turnover factors in a Ubp3p-dependent manner during nitrogen starvation. While ribophagy is thought to mediate the reutilization of scarce resources during nutrient limitation, our results suggest that the selective degradation of specific proteins could also facilitate a broader reprogramming of the post-transcriptional control of gene expression.
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影响因子：
5.3
作者：
Koh, JY;Hájek, P;Bedwell, DM
通讯作者：
Bedwell, DM
影响因子：
16
作者：
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通讯作者：
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影响因子：
64.8
作者：
Amrani, Nadia;Ghosh, Shubhendu;Jacobson, Allan
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DOI：
10.1073/pnas.240444197
发表时间：
2000-11-21
影响因子：
11.1
作者：
Chan, TF;Carvalho, J;Zheng, XFS
通讯作者：
Zheng, XFS
DOI：
10.1016/j.bbamcr.2011.07.011
发表时间：
2012-01-01
影响因子：
5.1
作者：
Dargemont, Catherine;Ossareh-Nazari, Batool
通讯作者：
Ossareh-Nazari, Batool