Hsp70 forms antiparallel dimers stabilized by post-translational modifications to position clients for transfer to Hsp90.
Hsp70 forms antiparallel dimers stabilized by post-translational modifications to position clients for transfer to Hsp90.
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DOI：
10.1016/j.celrep.2015.03.063
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发表时间：
2015-05-05
期刊：
影响因子：
8.8
通讯作者：
Robinson CV
中科院分区：
文献类型：
--
作者：
Morgner N;Schmidt C;Beilsten-Edmands V;Ebong IO;Patel NA;Clerico EM;Kirschke E;Daturpalli S;Jackson SE;Agard D;Robinson CV
细胞中蛋白质的折叠受分子伴侣网络的调控，包括热休克蛋白70（Hsp70）系统，其由Hsp40辅分子伴侣和核苷酸交换因子组成。Hsp40在与Hsp90相互作用之前介导Hsp70和客户蛋白之间的复合物形成。我们使用质谱（MS）监测真核细胞Hsp90/Hsp70/Hsp40，Hop，p23和客户蛋白，糖皮质激素受体（GR）的片段之间形成的组件。我们发现，热休克蛋白40促进客户端和热休克蛋白70之间的相互作用，并促进单体热休克蛋白70的二聚化。这种二聚化是反平行的，稳定的翻译后修饰（PTM），并保持在稳定的heterohexameric客户端加载复合物Hsp902Hsp702HopGR确定在这里。添加p23到该客户端加载复合物诱导GR转移到Hsp90上，并导致Hop和Hsp70的排出。基于这些结果，我们建议热休克蛋白70的反平行二聚化，稳定的PTM，客户端的位置从热休克蛋白70转移到热休克蛋白90。Hsp70的反平行二聚化通过PTM稳定Hsp40催化Hsp70二聚化和客户端转移到Hsp70 Hsp70反平行二聚化在客户端负载复合物中维持。结合联合收割机天然质谱和化学交联来确定Hsp70/90分子伴侣系统的相互作用。他们表明，Hsp70二聚化是反平行的，并通过PTM稳定。他们监测分子伴侣复合物的形成，并发现了含有Hsp70二聚体的六聚体客户端加载复合物。
Protein folding in cells is regulated by networks of chaperones, including the heat shock protein 70 (Hsp70) system, which consists of the Hsp40 cochaperone and a nucleotide exchange factor. Hsp40 mediates complex formation between Hsp70 and client proteins prior to interaction with Hsp90. We used mass spectrometry (MS) to monitor assemblies formed between eukaryotic Hsp90/Hsp70/Hsp40, Hop, p23, and a client protein, a fragment of the glucocorticoid receptor (GR). We found that Hsp40 promotes interactions between the client and Hsp70, and facilitates dimerization of monomeric Hsp70. This dimerization is antiparallel, stabilized by post-translational modifications (PTMs), and maintained in the stable heterohexameric client-loading complex Hsp902Hsp702HopGR identified here. Addition of p23 to this client-loading complex induces transfer of GR onto Hsp90 and leads to expulsion of Hop and Hsp70. Based on these results, we propose that Hsp70 antiparallel dimerization, stabilized by PTMs, positions the client for transfer from Hsp70 to Hsp90. Antiparallel dimerization of Hsp70 is stabilized by PTMs Hsp40 catalyzes Hsp70 dimerization and client transfer to Hsp70 Hsp70 antiparallel dimerization is maintained in the client-loading complex Addition of p23 induces transfer of GR onto Hsp90 and loss of Hop and Hsp70 Morgner et al. combine native mass spectrometry and chemical crosslinking to define the interactions of the Hsp70/90 chaperone system. They show that Hsp70 dimerization is antiparallel and stabilized by PTMs. They monitor the formation of chaperone complexes and discover a hexameric client-loading complex containing an Hsp70 dimer.
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影响因子：
2.9
作者：
BENAROUDJ, N;BATELIER, G;LADJIMI, MM
通讯作者：
LADJIMI, MM
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作者：
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