蓝藻prx基因家族成员功能研究

项目名称： 蓝藻prx基因家族成员功能研究

项目编号： No.31200091

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 微生物学、植物学

项目作者： 赵宇玮

作者单位： 西北大学

项目金额： 22万元

中文摘要： peroxiredoxin（prx）基因家族的表达产物是植物和蓝藻细胞内抗氧化防御系统的核心因子。蓝藻S. elongatus PCC 7942 基因组共编码6个不同prx基因家族的成员，逆境胁迫条件下这些基因呈现出差异表达的特性。2-Cys Prx蛋白还能够保持周期大约为24小时的周期性氧化状态循环。这一现象与传统细胞"生物钟"分子机理，即"核心钟"元件依靠转录-翻译负反馈机制（TTFL）维持运转的模式完全不同。本项目拟分别构建蓝藻prx基因家族的单基因或双基因敲除细胞系，并对所有基因敲除系进行抗逆性表型分析，为确定prx基因家族的6个成员各自不同的功能定位寻找确凿的分子证据。如能确定蓝藻细胞内存在与真核细胞性质类似的不依赖于转录调控，由2-Cys Prx 氧化还原状态周期性变化组织的保守生物节律性遗传标签，将推进人们对于生物钟分子机制的认识，为进一步应用生物钟理论于生产实践打下基础。

中文关键词： 蓝藻；过氧化还原蛋白；活性氧；基因敲除；生物节律性

英文摘要： Peroxiredoxins (Prx) are central elements of the antioxidant defense system in the plant cells and cyanobacterial cells. The primary function of Prxs is working as thiol-dependent enzymes that decompose peroxides. Thus, they belong to the enzyme group of peroxidases. Prx proteins undergo major conformational changes in dependence of their redox state. Thus, they not only modulate cellular reactive oxygen species- and reactive nitrogen species dependent signaling, but depending on the Prx type they sense the redox state, transmit redox information to binding partners, and function as chaperone or molecular switch. The genome DNA of Cyanobacterium S. elongatus PCC 7942 encodes 6 different members of prx gene family. Under the stress triggered by the intracellular ROS boosting, the expression pattern of these different members of prx family exhibites a gene specific manner. Interestingly, the 2-Cys Prx, highly conserved antioxidant proteins, undergo 24 hour redox cycles, which persists for many days under constant light and temprature conditions. This phenomenon is quitely different from the molecular mechanism of current models of bioclock，the latter ,i.e "Central Clock" is based on the transcription-translation feedback loops(TTFL). This project will construct different Cyanobacterium cell strains with singl

英文关键词： Cyanobacterium；peroxiredoxin；Reactive Oxygen Species；gene knockout；circadian rhythm