Cytosolic HSP90 regulates the heat shock response that is responsible for heat acclimation in Arabidopsis thaliana
Cytosolic HSP90 regulates the heat shock response that is responsible for heat acclimation in Arabidopsis thaliana
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DOI：
10.1074/jbc.m707168200
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发表时间：
2007-12-28
影响因子：
4.8
通讯作者：
Nishimura, Mikio
中科院分区：
文献类型：
--
作者：
Yamada, Kenji;Fukao, Yoichiro;Nishimura, Mikio
植物的生存需要适应高温的能力。植物受到热激，基因的表达被诱导，并且植物变得耐受较高的温度。我们发现，用热激蛋白90（HSP 90）和根赤霉素（radicol）瞬时处理诱导了热诱导基因和热锻炼。热休克降低外源性糖皮质激素受体（GR）的活性。由于活性依赖于HSP 90，这表明热降低了体内胞质HSP 90的活性。微阵列显示，许多被热休克和HSP90抑制剂上调的基因参与蛋白质和降解，这表明维持系统的激活是这种反应的关键部分。这些基因的启动子大多具有热休克反应元件样结构，表明热休克因子（HSF）参与了对热休克蛋白90的反应。包括AtHsfA1d。重组AtHsfA1d蛋白是热休克反应元件基序，与拟南芥胞质HSP90，HSP90.2相互作用。HSP90.2阴性表达诱导热诱导基因的表达。因此，在没有热休克的情况下，胞质HSP90通过主动抑制功能来调节热诱导基因。热休克时，胞浆HSP90是短暂的，这可能导致HSF激活。
Plant survival requires the ability to acclimate to heat. plants are subjected to heat shock, the expression of genes is induced, and the plants become tolerant of higher We found that transient treatment with and radicicol, two heat shock protein 90 (HSP90) induced heat-inducible genes and heat acclimation in thaliana seedlings. Heat shock reduced the activity exogenously expressed glucocorticoid receptor (GR). Since activity depends on HSP90, this suggests that heat reduces cytosolic HSP90 activity in vivo. Microarray revealed that many of the genes that are up-regulated by heat shock and HSP90 inhibitors are involved in protein and degradation, suggesting that the activation of a maintenance system is a crucial part of this response. Most these genes have heat shock response element-like motifs their promoters, which suggests that heat shock factor (HSF) is involved in the response to HSP90 Several HSF genes are expressed constitutively in A. including AtHsfA1d. Recombinant AtHsfA1d protein the heat shock response element motif and interacts with thaliana cytosolic HSP90, HSP90.2. Overexpression of a negative form of HSP90.2 induced the heat-induciblegene. Thus, appears that in the absence of heat shock, cytosolic HSP90 regulates heat-inducible genes by actively suppressing function. Upon heat shock, cytosolic HSP90 is transiently which may lead to HSF activation.