Translational Control of RuBPCase Gene Expression in Amaranth

苋菜中 RuBPCase 基因表达的翻译控制

• 批准号: 9316806
• 负责人: James Berry
• 金额: $ 28.2万
• 依托单位: SUNY at Buffalo
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-03-01 至 1998-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9316806&HistoricalAwards=false
• 关键词: Translational; Control; RuBPCase; Gene; Expression

Berry 9316806 Photomorphogenesis, the phenomenon of growth and development in response to light, provides a valuable experimental system to study the control of gene expression by environmental stimuli. In Amaranth seedlings, light coordinately regulates the expression of genes encoding the large subunit (LSU) and small subunit (SSU) of ribulose 1,5-bisphosphate carboxylase (RuBPCase), a principle enzyme in photosynthetic carbon fixation. While long-term changes in RuBPCase gene expression are regulated by light at the level of mRNA accumulation, very rapid changes in RuBPCase gene expression are induced at two translational levels. RuBPCase synthesis is rapidly induced at the level of translation initiation when dark- grown seedlings are transferred to light (light-shift), and is rapidly blocked at the level of translation elongation when light- grown seedlings are transferred to darkness. We propose to investigate the regulation of chloroplast-encoded LSU and nuclear- encoded SSU at these two translation steps. Regulation of translation initiation will be investigated in light-grown, dark- grown, and light-shifted seedlings by analysis of polysome- associated proteins, analysis of proteins that associate with RuBPCase mRNAs, and by in vivo and in vitro analysis of RNA sequences and associated factors. Regulation of translation elongation will be studied in light-grown and dark-shifted seedlings by analysis of ribosome distribution and sites of ribosome pausing, analysis of the elongation block in homologous translation runoff extracts, and analysis of polysome-associated proteins. The investigations proposed will provide new insights into coordinate regulation of expression of nuclear- and plastid- encoded genes at the translational level. %%% In plants, light serves as an environmental signal that regulates development. Investigations into light-regulated responses in plants are important in determining how factors that control plant development respo nd to environmental stimuli, such as light. To begin to understand how this occurs, we will study light-control of plant genes responsible for forming the carbon dioxide fixation enzyme in Amaranth, a grain plant. Experiments will be performed to observe how light exposure can control rapid changes in the amounts of the enzyme in the plant. This appears to happen at the level of messenger RNA, which is produced from DNA and afterwards is translated into the plant carbon dioxide fixation protein. Results of this research will provide unique perspectives about light on the genetic control in photosynthesis. In addition, our basic research with Amaranth will contribute to the development of the plant as an important agricultural crop for food production and for industry. ***

光形态发生是指生长和发育对光的反应，它为研究环境刺激对基因表达的控制提供了一个有价值的实验系统。 在阿马兰斯幼苗中，光协同调节编码核酮糖1，5-二磷酸羧化酶（RuBPCase）大亚基（LSU）和小亚基（SSU）基因的表达。 虽然RuBPCase基因表达的长期变化在mRNA积累水平上受光调控，但RuBPCase基因表达的快速变化在两个翻译水平上诱导。 当黑暗生长的幼苗被转移到光照（光移）时，RuBPCase合成在翻译起始水平被快速诱导，并且当光照生长的幼苗被转移到黑暗时，RuBPCase合成在翻译延伸水平被快速阻断。 我们打算研究叶绿体编码的LSU和核编码的SSU在这两个翻译步骤中的调控。 将通过分析多核糖体相关蛋白、分析与RuBPCase mRNA相关的蛋白以及通过体内和体外分析RNA序列和相关因子，在光生长、暗生长和光转移的幼苗中研究翻译起始的调节。 通过分析核糖体分布和核糖体暂停位点，分析同源翻译径流提取物中的延伸块，以及分析多聚体相关蛋白，将在光照生长和暗移幼苗中研究翻译延伸的调节。 这些研究将为在翻译水平上协调调节核和质体编码基因的表达提供新的见解。 在植物中，光作为环境信号调节发育。 研究植物的光调节反应对于确定控制植物发育的因素如何对环境刺激（如光）作出反应是很重要的。 为了开始了解这是如何发生的，我们将研究负责形成阿马兰斯（一种谷类植物）二氧化碳固定酶的植物基因的光控制。 将进行实验以观察光照如何控制植物中酶含量的快速变化。 这似乎发生在信使RNA的水平上，信使RNA由DNA产生，然后被翻译成植物二氧化碳固定蛋白。 该研究结果将为光在光合作用遗传调控中的作用提供独特的视角。 此外，我们对阿马兰斯的基础研究将有助于该植物作为重要的粮食生产和工业农作物的发展。 ***