Arabidopsis ROF1 (FKBP62) modulates thermotolerance by interacting with HSP90.1 and affecting the accumulation of HsfA2-regulated sHSPs
Arabidopsis ROF1 (FKBP62) modulates thermotolerance by interacting with HSP90.1 and affecting the accumulation of HsfA2-regulated sHSPs
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DOI：
10.1111/j.1365-313x.2009.03878.x
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发表时间：
2009-08-01
期刊：
影响因子：
7.2
通讯作者：
Breiman, Adina
中科院分区：
文献类型：
--
作者：
Meiri, David;Breiman, Adina
P>拟南芥ROF1 （AtFKBP62）是一种肽基脯氨酸顺/反式异构酶，是FKBP （FK506结合蛋白）家族的成员。ROF1的表达受热应激诱导并受发育调控。在本研究中，我们发现ROF1通过其四肽重复结构域与热休克蛋白HSP90.1结合，并在正常条件下定位于细胞质中。暴露于热应激诱导ROF1-HSP90.1复合物的核定位，这依赖于转录因子HsfA2的存在，HsfA2与HSP90.1相互作用，但与ROF1不相互作用。在拟南芥HSP90.1和HsfA2敲除突变体中未检测到ROF1的核定位。rof1基因敲除植株在37℃驯化和45℃暴露之间经过24-48 h后出现了枯萎现象。转基因rof1过表达植株在45℃环境下的存活率高于野生型植株。在rof1基因敲除突变体中，受HsfA2调控的小热休克蛋白的表达水平在暴露于37℃并恢复24-48 h后显著降低，并且与突变体表型密切相关。我们认为ROF1通过维持在高温下生存所必需的小热敏感蛋白水平，在延长耐热性方面发挥作用。
P>Arabidopsis ROF1 (AtFKBP62) is a peptidyl prolyl cis/trans isomerase and a member of the FKBP (FK506 binding protein) family. ROF1 expression is induced by heat stress and developmentally regulated. In this study, we show that ROF1 binds heat shock proteins HSP90.1 via its tetratricopeptide repeat domain, and localizes in the cytoplasm under normal conditions. Exposure to heat stress induces nuclear localization of the ROF1-HSP90.1 complex, which is dependent upon the presence of the transcription factor HsfA2, which interacts with HSP90.1 but not with ROF1. Nuclear localization of ROF1 was not detected in Arabidopsis HSP90.1 and HsfA2 knockout mutants. The rof1 knockout plants exhibited collapse when 24-48 h passed between acclimation at 37 degrees C and exposure to 45 degrees C. Transgenic ROF1 over-expressors showed better survival in response to exposure to 45 degrees C than wild-type plants did. In rof1 knockout mutants, the level of expression of small HSPs regulated by HsfA2 was dramatically reduced after exposure to 37 degrees C and recovery for 24-48 h, and correlates well with the mutant phenotype. We suggest a role for ROF1 in prolongation of thermotolerance by sustaining the levels of small HSPs that are essential for survival at high temperatures.