染色质重塑因子调控内质网胁迫诱导的PCD的分子机理研究

项目名称： 染色质重塑因子调控内质网胁迫诱导的PCD的分子机理研究

项目编号： No.31470353

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 生物科学

项目作者： 刘建祥

作者单位： 复旦大学

项目金额： 90万元

中文摘要： 高温、高盐与病原菌侵染等逆境胁迫容易引起蛋白错误折叠。当模式植物拟南芥内质网内错误折叠蛋白大量积累时，细胞启动内质网胁迫应答（未折叠蛋白应答，UPR），通过蛋白裂解和非常规剪切分别活化膜结合转录因子AtbZIP28和AtbZIP60，调节一系列下游基因，增强蛋白折叠能力，加速错误折叠蛋白的降解，促进细胞生存。当内质网胁迫较严重时，细胞激活程序性细胞死亡（PCD）途径，主动杀死部分细胞，但相关分子机理研究较少。本课题组最近发现膜结合转录因AtNAC089调控了植物内质网胁迫诱导的PCD。AtNAC089调控通路的发现为研究植物内质网胁迫下PCD的分子机理提供了新的切入点。本项目拟研究拟南芥AtNAC089下游两个染色质重塑因子AtCHR-A和AtCHR-B在内质网胁迫诱导的PCD中的生物功能、作用机理及其与高温和氧化胁迫等逆境胁迫抗性的关系，为精确调控逆境条件下细胞生存与死亡的平衡奠定基础。

中文关键词： 拟南芥；逆境胁迫；分子机制；染色质重塑因子；程序性细胞死亡（PCD）

英文摘要： Environmental stresses, such as heat, salinity and pathogen infection, induce protein misfolding in plants. When unfolded or misfolded proteins accumulate in the endoplasmic reticulumn (ER) in Arabidopsis, a well-conserved response called the unfolded protein response (UPR) is elicited to bring protein folding and degradation capacity in line with demands either by enhancing the protein folding or degradation machinery to ensure cell survial. Two membrane-associated transcriptions factors (MTFs), AtbZIP28 and AtbZIP60, were previously identified as the key regulators for plant UPR to promote cell survival. The UPR also induces programmed cell death (PCD) when the ER stress is severe; however, the underlying molecular mechanisms are less understood, especially in plants. Recently, we have identified another MTF, AtNAC089, as an important regulator of ER stress-induced PCD in plants, which provides more opportunities for further understanding new molecular components involved in plant PCD, especially under ER stress conditions. In the current proposal, we are planning to characterize two chromatin remodeling factors (CHRs) which are downstream genes of AtNAC089. The biological function and underlying molecular mechanisms of two CHRs in ER-stress-induced PCD in plants, and its relationship to environmental stress tolerance will be substantially invesitgated, which should be important for understanding the balance between cell survial and cell death during plant environmental stress responses.

英文关键词： Arabidopsis;Environmental stress response;Molecular mechanism;Chromatin remodeling factor;Programmed cell death (PCD)