Subunit interaction maps for the regulatory particle of the 26S proteasome and the COP9 signalosome
Subunit interaction maps for the regulatory particle of the 26S proteasome and the COP9 signalosome
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DOI：
10.1093/emboj/20.24.7096
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发表时间：
2001-12-17
期刊：
影响因子：
11.4
通讯作者：
Vierstra, RD
中科院分区：
文献类型：
--
作者：
Fu, HY;Reis, N;Vierstra, RD
26S蛋白酶体在真核蛋白的分解，特别是泛素标记蛋白的分解中起着重要作用。底物特异性是由调节颗粒（RP）赋予的，它可以解离成稳定的盖子和碱亚配合物。为了帮助确定RP的分子结构，我们通过酵母双杂交分析测试了酿酒酵母亚基之间所有可能的配对相互作用。在基础中，Rpt4/5/3/6交互集群是明显的。在盖子内，Rpn5/11/9/8周围形成了一个结构簇。在拟南芥COP9信号体（CSN）的同义亚基（Csn4/5/7/6）之间检测到相互作用，暗示了类似的四元排列。在盖子、碱基或核心颗粒亚配合物之间没有检测到配对相互作用，这表明它们之间的稳定接触需要事先组装。突变分析确定了atp酶、coil -coil、PCI和MPN结构域对RP组装很重要。Rpn10的vWA结构域中的单个残基对于氨基酸类似物抗性、降解泛素融合降解底物和稳定盖碱结合是必不可少的。26S蛋白酶体和CSN的综合亚基相互作用图谱支持这两个复合物的祖先关系。
The 26S proteasome plays a major role in eukaryotic protein breakdown, especially for ubiquitin-tagged proteins. Substrate specificity is conferred by the regulatory particle (RP), which can dissociate into stable lid and base subcomplexes. To help define the molecular organization of the RP, we tested all possible paired interactions among subunits from Saccharomyces cerevisiae by yeast two-hybrid analysis. Within the base, a Rpt4/5/3/6 interaction cluster was evident. Within the lid, a structural cluster formed around Rpn5/11/9/8. Interactions were detected among synonymous subunits (Csn4/5/7/6) from the evolutionarily related COP9 signalosome (CSN) from Arabidopsis, implying a similar quaternary arrangement. No paired interactions were detected between lid, base or core particle subcomplexes, suggesting that stable contacts between them require prior assembly. Mutational analysis defined the ATPase, coiled-coil, PCI and MPN domains as important for RP assembly. A single residue in the vWA domain of Rpn10 is essential for amino acid analog resistance, for degrading a ubiquitin fusion degradation substrate and for stabilizing lid-base association. Comprehensive subunit interaction maps for the 26S proteasome and CSN support the ancestral relationship of these two complexes.