Effect of mutation of the tetratricopeptide repeat and asparatate-proline 2 domains of stil on Hsp90 signaling and interaction in Saccharomyces cerevisiae
Effect of mutation of the tetratricopeptide repeat and asparatate-proline 2 domains of stil on Hsp90 signaling and interaction in Saccharomyces cerevisiae
复制标题
DOI：
10.1534/genetics.105.045815
复制
发表时间：
2006-01-01
期刊：
影响因子：
3.3
通讯作者：
Johnson, JL
中科院分区：
文献类型：
--
作者：
Flom, G;Weekes, J;Johnson, JL
通过与热休克蛋白70和热休克蛋白90通过单独的tetratricopeptide repeat（TPR）结构域的同时相互作用，共伴侣蛋白Hop/Sti 1已被提出在客户端蛋白从热休克蛋白70转移到热休克蛋白90中发挥关键作用。然而，没有先前的突变分析表明，在体内的关键作用的TPR结构域的斯蒂尔已被报道。我们使用TPR结构域的定点诱变结合遗传筛选来分离破坏Stil功能的突变。TPR 2A中的单个氨基酸改变破坏了Hsp 90在体内的相互作用，但没有显着影响功能。然而，TPR 2A中保守残基的缺失或羧基末端DP 2结构域的突变完全破坏了Stil的功能。令人惊讶的是，以前显示与Hsp 70相互作用的TPR 1突变不足以破坏体内功能，除非与TPR 2B突变结合，这表明TPR 1和TPR 2B具有冗余或重叠的体内功能。我们进一步研究了Stil与突变形式的Hsp 90的遗传和物理相互作用，为Stil的TPR 2A结构域在调节Hsp 90功能中的重要性提供了见解。
Through simultaneous interactions with Hsp70 and Hsp90 via separate tetratricopeptide repeat (TPR) domains, the cochaperone protein Hop/Sti1 has been proposed to play a critical role in the transfer of client proteins from Hsp70 to Hsp90. However, no prior mutational analysis demonstrating a critical in vivo role for the TPR domains of Stil has been reported. We used site-directed mutagenesis of the TPR domains combined with a genetic screen to isolate mutations that disrupt Stil function. A single amino acid alteration in TPR2A disrupted Hsp90 interaction in vivo but did not significantly affect function. However, deletion of a conserved residue in TPR2A or mutations in the carboxy-terminal DP2 domain completely disrupted Stil function. Surprisingly, mutations in TPR1, previously shown to interact with Hsp70, were not sufficient to disrupt in vivo functions unless combined with mutations in TPR2B, suggesting that TPR1 and TPR2B have redundant or overlapping in vivo functions. We further examined the genetic and physical interaction of Stil with a mutant form of Hsp90, providing insight into the importance of the TPR2A domain of Stil in regulating Hsp90 function.