内含子中启动子元件调控菜豆PvSR2基因转录的机制

项目名称： 内含子中启动子元件调控菜豆PvSR2基因转录的机制

项目编号： No.31271293

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 生物科学

项目作者： 祁晓廷

作者单位： 首都师范大学

项目金额： 80万元

中文摘要： 内含子中启动子(intronic promoter)是内含子调控基因转录的重要元件，在基因表达多样性方面发挥着重要作用。植物内含子中启动子研究还处于初级阶段，仅在几个基因（包括我们报道的菜豆PvSR2基因）内含子中发现启动子，这些启动子调控基因转录的机制还不清楚。近期工作表明PvSR2内含子中启动子产生一个在茎、叶特异表达的转录本，赋予PvSR2器官特异表达模式。该转录本编码一个能与上游启动子结合并激活PvSR2表达的转录因子NP2，形成一个自调控环路。在此基础上，本项目综合应用细胞、分子和遗传学技术，解析NP2识别的启动子元件，筛选NP2互作的PvSR2转录调控因子，鉴定内含子中启动子器官特异响应区段及其结合转录因子。通过这些研究最终阐明内含子中启动子调控PvSR2转录两种方式（自调控环路和器官特异表达）的分子机制。研究结果对揭示内含子中启动子调控植物基因转录方式及其机制具有一定意义。

中文关键词： 转录因子；内含子中启动子；镉胁迫；热胁迫；可变剪接

英文摘要： Intron plays important roles in a gene expression. Recent studies have shown that the alternative intronic promoter usage is an important source for generating protein and regulatory diversity from the same gene. Although several intronic promoters are found in a few plant genes including our previously reported bean PvSR2 gene, the transcriptional regulation of these plant genes by their intronic promoters remain largely unknown. To provide further evidence for this, we characterized the roles of intronic promoter on the PvSR2 transcription. We revealed that PvSR2 generated a shorter PvSR2 transcript (S-PvSR2) through the use of intronic promoter. S-PvSR2 was predominantly expressed in aerial organs (leaf and stem). Immunoblot assay confirmed that S-PvSR2 encodes a novel 60-anino acid protein distinct from PvSR2, which named as NP2 (novel PvSR2). NP2 seemed to function as a transcription factor, because it was localized to the nucleus and showed the transcriptional activation activity in yeast. Interestingly, NP2 bound to the PvSR2 upstream promoter and thereby increased the PvSR2 expression, thus constituting a positive autoregulatory loop. We apply this proposal based on above results. The overall objective of this proposal is to further understand the intronic promoter-mediated transcriptional regulation o

英文关键词： transcription factor；intronic promoter；cadmium stress；heat shock；alterniative splicing