Nucleotides and two functional states of hsp90
Nucleotides and two functional states of hsp90
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DOI：
10.1074/jbc.272.12.8007
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发表时间：
1997-03-21
影响因子：
4.8
通讯作者：
Toft, D
中科院分区：
文献类型：
--
作者：
Sullivan, W;Stensgard, B;Toft, D
先前的研究已经证明了ATP依赖性的复合物的形成，该复合物包含热休克蛋白hsp 90、独特的hsp 90结合蛋白p23和三种高分子量免疫亲素之一。在本研究中，显示hsp 90和p23形成需要升高的温度和ATP/Mg 2+的复合物。复合物的形成强烈促进的非离子型洗涤剂Nonidet P-40。ADP和苯醌安莎霉素、格尔德霉素是复合物形成的有效抑制剂。ATP依赖性过程改变了热休克蛋白90的状态，而不是p23，并影响了热休克蛋白90与苯基琼脂糖凝胶结合的能力。热休克蛋白90转化为ATP结合状态降低了其对苯基琼脂糖的亲和力。这些结果表明，热休克蛋白90可以存在于至少两个功能状态，一个能够结合p23和另一个具有高亲和力的疏水树脂。提出了一个模型，其中这些状态是由ATP或ADP的结合。
Previous studies have demonstrated the ATP-dependent formation of a complex containing the heat shock protein hsp90, the unique hsp90 binding protein p23, and one of three high molecular weight immunophilins. In the present study, hsp90 and p23 are shown 60 form a complex that requires elevated temperature and ATP/Mg2+. Complex formation is strongly promoted by molybdate and by the nonionic detergent Nonidet P-40. ADP and the benzoquinone ansamycin, geldanamycin, are potent inhibitors of complex formation. The ATP-dependent process alters the state of hsp90, not p23, and influences the ability of hsp90 to bind to phenyl-Sepharose. Conversion of hsp90 to the ATP-bound state lowers its affinity for phenyl-Sepharose. These results show that hsp90 can exist in at least two functional states, one able to bind p23 and the other with a high affinity for hydrophobic resins. A model is presented where these states are dictated by the binding of either ATP or ADP.