Biochemistry of Signal-Responsive Transcription in Plants

植物信号响应转录的生物化学

• 批准号: 9728789
• 负责人: Jonathan Arias
• 金额: --
• 依托单位: University of Maryland Biotechnology Institute
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-03-01 至 2001-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9728789&HistoricalAwards=false
• 关键词: Biochemistry; Signal; Responsive; Transcription; Plants

9728789 Arias The overall objective of this project is to understand how specific plant TGA factors contribute to as-1 dependent gene expression in plants. Towards this end, the investigator's laboratory developed transient and stable transfection systems with tobacco protoplasts and cells to evaluate the trans-activation of target reporter genes by endogenous or transiently-expressed factors in response to defined stimuli. With one of these model systems they found that two distinct as-1 binding proteins, termed TGA1a and VBP1, increase transcription in response to auxins and xenobiotic stress through a mechanism that does not involve a change in DNA-binding, dimerization, or nuclear localization functions of their bZIP domains. The first goal is to identify by in vivo gain-of-function assays the specific domains and residues that determine basal and auxin-responsive activation by TGA1a. The second goal is to directly test by in vivo labeling and phosphopeptide mapping, whether auxin induces a change in the phosphorylation state of transiently-expressed TGA1a. The importance of the phosphoacceptor site to trans-activation and other functions will be evaluated with mutant forms of these factors in transient-expression assays. The third goal is to use protein-binding assays to characterize a 120 kDA tobacco protein that selectively and stably associates with TGA1a. The binding site for this protein will be mapped with transiently-expressed, mutant forms of TGA1a in a co-immunoprecipitation assay. The question of whether the association of this protein with TGA1a is auxin-responsive will also be investigated. Completion of these objectives will provide important new information on how plant hormone and chemical-stress cues stimulate the activity of a plant DNA-binding protein that regulates gene expression. The proposed studies are likely to make significant contributions towards current efforts at understanding how gene expression in eukaryotes, and especially in plants, is regulated. Such knowledge may lead to the development of novel regulatory systems for controlling the expression of economically-important genes in plants.

小阿里亚斯9728789 本项目的总体目标是了解特定的植物TGA因子如何促进植物中依赖AS-1的基因表达。 为此，研究人员的实验室开发了瞬时和稳定的转染系统与烟草原生质体和细胞，以评估目标报告基因的反式激活的内源性或瞬时表达的因素，在定义的刺激。通过这些模型系统中的一个，他们发现两种不同的as-1结合蛋白，称为TGA 1a和VBP 1，通过一种不涉及其bZIP结构域的DNA结合，二聚化或核定位功能变化的机制来增加对生长素和异生素胁迫的转录。第一个目标是通过体内功能获得性测定来鉴定确定由TGA 1a引起的基础和生长素响应性激活的特定结构域和残基。第二个目标是通过体内标记和磷酸肽图谱直接测试生长素是否诱导瞬时表达的TGA 1a的磷酸化状态的变化。磷酸化受体位点对反式激活和其他功能的重要性将在瞬时表达试验中用这些因子的突变形式进行评价。第三个目标是使用蛋白结合测定来表征选择性地和稳定地与TGA 1a缔合的120 kDA烟草蛋白。该蛋白的结合位点将在免疫共沉淀试验中与瞬时表达的TGA 1a突变形式作图。该蛋白与TGA 1a的关联是否是生长素响应的问题也将被研究。 这些目标的完成将提供重要的新信息，植物激素和化学胁迫线索如何刺激植物DNA结合蛋白的活性，调节基因表达。拟议的研究可能会作出重大贡献，对目前的努力，了解如何在真核生物，特别是在植物中的基因表达，是受管制的。这些知识可能会导致新的调控系统的发展，用于控制植物中的经济重要基因的表达。