Pba3-Pba4 heterodimer acts as a molecular matchmaker in proteasome α-ring formation
Pba3-Pba4 heterodimer acts as a molecular matchmaker in proteasome α-ring formation
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DOI：
10.1016/j.bbrc.2014.06.119
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发表时间：
2014-07-25
影响因子：
3.1
通讯作者：
Kato, Koichi
中科院分区：
文献类型：
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作者：
Takagi, Kenji;Saeki, Yasushi;Kato, Koichi
真核蛋白酶体组装由多个专用伴侣协助。在酵母中，异二聚分子伴侣 Pba3-Pba4 促进由 α1-α7 亚基组成的异七聚环的形成。在这里，我们揭示，在缺乏这种二聚伴侣的情况下，α2在α环组装过程中取代了α4，从而产生了缺乏α4、β3、β5、β6和β7亚基以及α4聚集体的非生产性复合物。此外，我们的结构引导突变数据表明，Pba3-Pba4异二聚体充当分子媒人，增强了α4和α之间的相互作用5，这是α环形成的关键步骤。 (C) 2014 Elsevier Inc. 保留所有权利。
Eukaryotic proteasome assembly is assisted by multiple dedicated chaperones. In yeast, formation of the heteroheptameric ring composed of alpha 1-alpha 7 subunits is promoted by the heterodimeric chaperone Pba3-Pba4. Here we reveal that in the absence of this dimeric chaperone, alpha 2 replaces alpha 4 during alpha-ring assembly, thereby giving rise to a non-productive complex that lacks alpha 4, beta 3, beta 5, beta 6, and beta 7 subunits and aggregates of alpha 4. Furthermore, our structure-guided mutational data demonstrate that the Pba3-Pba4 heterodimer acts as molecular matchmaker reinforcing the interaction between alpha 4 and alpha 5, which is the crucial step in the alpha-ring formation. (C) 2014 Elsevier Inc. All rights reserved.