Calmodulin-binding protein phosphatase PP7 is involved in thermotolerance in Arabidopsis
Calmodulin-binding protein phosphatase PP7 is involved in thermotolerance in Arabidopsis
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DOI：
10.1111/j.1365-3040.2006.01613.x
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发表时间：
2007-02-01
影响因子：
7.3
通讯作者：
Li, Bing
中科院分区：
文献类型：
--
作者：
Liu, Hong-Tao;Li, Guo-Liang;Li, Bing
PP 7是植物中发现的第一个与钙调素（CaM）相互作用的蛋白质Ser/Thr磷酸酶。利用T-DNA插入AtPP 7基因敲除株系和AtPP 7基因过表达株系研究AtPP 7的特异功能。AtPP 7基因敲除降低了拟南芥幼苗的耐热性，而AtPP 7基因过表达则提高了拟南芥幼苗的耐热性。实时荧光定量PCR结果显示，AtPP 7过表达株经37 ℃热休克1 h后，AtHSP 70和AtHSP 101基因表达上调。蛋白质凝胶印迹分析表明，在37 ℃下HS 2 h后，AtPP 7过表达系中的HSP 70蛋白水平增加。在野生型拟南芥中，在37 ℃下HS也诱导AtPP 7基因的表达。使用酵母双杂交筛选，我们发现AtPP 7和CaM之间的相互作用。此外，我们发现AtPP 7与HS转录因子（HSF）相互作用，这表明AtPP 7可能在调节热休克蛋白（HSP）基因的表达中起作用。
PP7 is the first protein Ser/Thr phosphatase to be found to interact with calmodulin (CaM) in plants. The T-DNA insertion AtPP7 knockout line and AtPP7 overexpression lines were employed to study the specific function of AtPP7. The AtPP7 knockout impaired the thermotolerance of Arabidopsis seedlings while the overexpression of AtPP7 resulted in plants with increased thermotolerance. Results from real-time polymerase chain reaction (PCR) showed that the expression of AtHSP70 and AtHSP101 genes was up-regulated in AtPP7 overexpression lines after heat shock (HS) at 37 degrees C for 1 h. Protein gel blot analysis showed that HSP70 protein levels increased in AtPP7 overexpression lines after HS at 37 degrees C for 2 h. The expression of the AtPP7 gene was also induced by HS at 37 degrees C in wild-type Arabidopsis. Using a yeast two-hybrid screen, we showed an interaction between AtPP7 and CaM. In addition, we found that AtPP7 interacts with an HS transcription factor (HSF), suggesting a possible role for AtPP7 in regulating the expression of heat shock protein (HSP) genes.