HOP is a monomer: investigation of the oligomeric state of the co-chaperone HOP.
HOP is a monomer: investigation of the oligomeric state of the co-chaperone HOP.
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HOP 是单体：共伴侣 HOP 寡聚状态的研究。
DOI：
10.1002/pro.278
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
Regan,Lynne
中科院分区：
文献类型：
--
作者：
Yi,Fang;Doudevski,Ivo;Regan,Lynne
共伴侣Hsp 70-Hsp 90组织蛋白（HOP）在体内蛋白质折叠中起着核心作用，结合Hsp 70和Hsp 90并将它们结合在一起形成功能复合物。文献中关于HOP的寡聚状态的报道一直不一致--它是单体、二聚体还是更高级的寡聚体？了解HOP的低聚状态很重要，因为它限制了折叠周期中可以形成的多蛋白复合物的数量和类型。因此，简化了可行模型的数量。在这里，我们明确调查寡聚状态的HOP使用三种互补的方法：凝胶过滤色谱法，沉降平衡分析超离心（AUC），和anin vivocexpression测定。我们发现，HOP不像一个单体的球状蛋白凝胶过滤。相反，它的行为与它是伸长的单体或二聚体一致。我们使用沉降平衡AUC对这些研究进行了随访，该AUC基于分子量（MW）进行分离，与形状无关。沉降平衡AUC清楚地表明HOP是单体，没有指示更高MW的物质。最后，我们使用了一种体内共表达试验，也支持了HOP是单体的结论。
The co‐chaperone Hsp70‐Hsp90 organizing protein (HOP) plays a central role in protein foldingin vivo,binding to both Hsp70 and Hsp90 and bringing them together in a functional complex. Reports in the literature concerning the oligomeric state of HOP have been inconsistent—is it a monomer, dimer, or higher order oligomer? Knowing the oligomeric state of HOP is important, because it places limits on the number and types of multiprotein complexes that can form during the folding cycle. Thus, the number of feasible models is simplified. Here, we explicitly investigate the oligomeric state of HOP using three complementary methods: gel filtration chromatography, sedimentation equilibrium analytical ultracentrifugation (AUC), and anin vivocoexpression assay. We find that HOP does not behave like a monomeric globular protein on gel filtration. Rather its behavior is consistent with it being either an elongated monomer or a dimer. We follow‐up on these studies using sedimentation equilibrium AUC, which separates on the basis of molecular weight (MW), independent of shape. Sedimentation equilibrium AUC clearly shows that HOP is a monomer, with no indication of higher MW species. Finally, we use anin vivocoexpression assay that also supports the conclusion that HOP is a monomer.