钙-钙调素信号通路调节热应激蛋白70表达的机制  

The Mechanism of Calcium and Calcium-activated Calmodulin Modulating the Expression of Hsp70

作　　者：齐晓楠[1] 赵园[1] 田文儒[1] 

机构地区：[1]青岛农业大学动物科技学院,青岛266109

出　　处：《农业生物技术学报》2015年第4期530-537,共8页Journal of Agricultural Biotechnology

基　　金：国家自然科学基金(No.31172378和No.31372313);山东省牛创新团队体系(SDAIT-12-011-03);青岛农业大学研究生创新项目(QYC201405)

摘　　要：随着温室效应的加剧,全球气候变暖已经成为现代畜牧业生产体系所面临的严峻挑战。高温炎热气候已成为影响畜禽生长繁殖的一种主要的非生物胁迫。热应激刺激时,动物体产生一系列生理变化来提高机体的耐受性,而本文旨在阐述钙(calcium,Ca2+)-钙调蛋白(calcium-activated calmodulin,Ca M)参与的耐热信号的转导机制,即热应激蛋白(heat shock proteins,Hsps)的表达机制。热应激时,细胞内Ca2+浓度上升,激活Ca M及其表达量的增加,随即Ca M作用于其下游的2种靶蛋白,即2条信号转导支路来提高热激转录因子1(heat shock factor 1,HSF1)的转录活性,进而调节热应激蛋白70(Hsp70)的表达。热应激时,Hsps表达的2条具体通路:1 Ca2+-Ca M激活下游的靶蛋白—钙/钙调素依赖性蛋白激酶Ⅱ(Ca2+/calmodulin-dependent protein kinaseⅡ,Ca MKⅡ),Ca MKⅡ通过促进HSF1(230)的磷酸化来提高HSF1的转录活性,进而诱导Hsp70的表达;2 Ca2+-Ca M激活下游另一个靶蛋白Hsp70,Hsp70通过与增多的Ca M形成复合物,释放HSF1单体,增多的HSF1形成有活性的HSF1三聚体,并入核与热激元件(heat shock element,HSE)结合,使HSF1具有转录活性,进而诱导Hsp70的表达。本文系统完整地综述了Ca2+-Ca MHSF1-Hsp70热应激信号系统,在感受、传导和响应热应激刺激时的机制。As the aggravation of the greenhouse effect, global warming has become a serious change for the modem animal husbandry and caused billions of dollars of losses annually around the world. Elevated temperature has become the major abiotic stress affecting animal growth. During heat shock, organisms experience orchestration of a multitude of biochemical and physiological changes to acquire heat resistance, and most of these depend on changes of heat shock proteins （lisps）. Therefore, this paper aimed to state the mechanism of the heat shock signal transduction that the Ca2 ＋-CaM involved in. The concentration of intracellular free Ca2 ~ is increased by heat stress, and CaM is activated by the increased Ca2 ＋, then CaM function on the 2 downstream target proteins that effect the transcriptional activity of HSF1 to regulate the expression of Hsp70. There are 2 specific pathways participating in the expression of Hsps： ①The transcriptional activity of HSF1 is increased by the phosphorylation of HSF1 （Ser230）, which was activated by CaMK Ⅱ that one of the downstream target proteins regulated by Ca2＋-CaM;② During heat shock, HSF1 is released, and activated by the compound of Hsp70-CaM for that Hsp70 is another downstream target proteins regulated by Ca2＋-CaM, HSF1 is converted from a transcriptional inactive monomer to active trimmer that is capable of binding to HSE and exhibits transcriptional activity, and finally induced the expression of Hsp70. The regulation activity of the HSF1 is the central mechanism of transcriptional regulation for Hsps gene expression. This paper reviewed the mechanism of the Ca：＋- CaM-HSF1-Hsp70 signal transduction system in reception, transduction and response to heat stress.

关 键 词：热应激 CA2+ 钙调蛋白(CaM) 热激转录因子1 热休克蛋白70 

分 类 号：S852.2[农业科学—基础兽医学]