N-Terminal Coiled-Coil Structure of ATPase Subunits of 26S Proteasome Is Crucial for Proteasome Function.
N-Terminal Coiled-Coil Structure of ATPase Subunits of 26S Proteasome Is Crucial for Proteasome Function.
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26S蛋白酶体的ATPase亚基的N末端卷曲线圈结构对于蛋白酶体功能至关重要。
DOI：
10.1371/journal.pone.0134056
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Genmei R
中科院分区：
文献类型：
--
作者：
Inobe T;Genmei R
蛋白酶体是真核细胞中必不可少的蛋白水解机器，它通过降解泛素化蛋白来去除受损蛋白并调节许多细胞活动。其异六聚体AAA+ atp酶Rpt亚基通过参与底物展开和降解易位在蛋白酶体活性中发挥核心作用；然而，其详细机制仍然知之甚少。与AAA+ atp酶结构域相比，它们的Rpt亚基的n端区域彼此之间存在很大差异。为了研究来自酿酒酵母的六个Rpt亚基的n端区域的需求和作用，我们使用条件敲除酵母菌株对每个Rpt亚基和碱基亚复合物的细菌异源表达系统进行了系统的突变分析。研究结果表明，Rpt亚基的n端区最重要的是线圈结构的形成。盘绕式线圈结构的主要作用是按照规定的顺序维持环形结构。然而，盘绕-盘绕区域也参与底物识别和底物与底物亚配合物之间的相互作用。
The proteasome is an essential proteolytic machine in eukaryotic cells, where it removes damaged proteins and regulates many cellular activities by degrading ubiquitinated proteins. Its heterohexameric AAA+ ATPase Rpt subunits play a central role in proteasome activity by the engagement of substrate unfolding and translocation for degradation; however, its detailed mechanism remains poorly understood. In contrast to AAA+ ATPase domains, their N-terminal regions of Rpt subunits substantially differ from each other. Here, to investigate the requirements and roles of the N-terminal regions of six Rpt subunits derived from Saccharomyces cerevisiae, we performed systematic mutational analysis using conditional knockdown yeast strains for each Rpt subunit and bacterial heterologous expression system of the base subcomplex. We showed that the formation of the coiled-coil structure was the most important for the N-terminal region of Rpt subunits. The primary role of coiled-coil structure would be the maintenance of the ring structure with the defined order. However, the coiled-coil region would be also be involved in substrate recognition and an interaction between lid and base subcomplexes.