Genetic Biochemical Studies of Plant Steroid Signaling

植物类固醇信号传导的遗传生化研究

• 批准号: 6603385
• 负责人: ZHIYONG WANG
• 金额: $ 26.54万
• 依托单位: CARNEGIE INSTITUTION OF WASHINGTON, D.C.
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-01 至 2007-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6603385
• 关键词: Arabidopsis; affinity chromatography; biochemistry; biological signal transduction; fluorescence resonance energy transfer; gene expression; gene interaction; gene mutation; hormone regulation /control mechanism; immunoprecipitation; mass spectrometry; microarray technology; phosphorylation; phytohormones; plant genetics; plant growth /development; plant proteins; polymerase chain reaction; protein structure function; steroid hormone; western blottings; yeast two hybrid system

DESCRIPTION (provided by applicant): Both animals and plants use steroids as signaling molecules (hormones) for physiological and developmental regulation. In plants, brassinosteroids (BRs) have growth-promoting activity and are essential for normal growth and development. Deficiencies in BR biosynthesis and responsiveness cause dramatic developmental alterations that include dwarfism due to reduced cell elongation and expansion, male sterility, delayed reproductive development, and development of light-grown morphology in the dark. BRs are perceived by the cell surface receptor kinase BAIl. How the BR signal is transduced from BRI1 on the plasma membrane to other cellular and nuclear responses remains unknown. This proposal aims at obtaining a molecular understanding of the BR signaling pathways in the model plant Arabidopsis thaliana, using approaches of molecular genetics, biochemistry, and cell biology. First, we have found that the BRI1 receptor kinase is in a large protein complex, and we hypothesize that other proteins associated with BRI1 in the receptor complex are required for the receptor function. We plan to identify the proteins associated with BRI1 using affinity purification and to characterize the functions of these proteins using reverse-genetic and molecular approaches. Second, we have isolated and carried out preliminary studies of a new BR-signaling mutant bzr1-1 D and the corresponding gene BZR1. Based on these studies, we hypothesize that BZR1 functions as a positive regulator in the BR response pathway downstream of BRI1. We plan to further characterize the BZR1 gene by identifying loss-of-function alleles of bzrl and bzr2, by analyzing the interaction of BZR1 with other genes of the BR signaling pathway, and by determining the biochemical activity of the BZR1 protein. We also plan to identify and characterize BZR1 interacting proteins and perform genetic studies of intragenic and extragenic mutations that suppress or enhance the bzr1 -1 D mutant phenotype. Finally, we have screened and isolated additional mutants associated with BR signaling. We have cloned the gene corresponding to one of these mutants, BZR6, which encodes a small protein. We hypothesize that BZR6 may function as a peptide ligand antagonizing BR signaling or as one of the secondary signals for the BR response. We plan to determine the functions of BZR6 and its homologue BZL1.

描述（由申请人提供）：动物和植物都使用类固醇作为 用于生理和发育调节的信号分子（激素）。 在植物中，油菜素类固醇 (BR) 具有促进生长的活性， 对于正常生长和发育至关重要。 BR生物合成的缺陷 和反应能力会导致巨大的发育变化，包括 由于细胞伸长和扩张减少、雄性不育、延迟性侏儒症 生殖发育和光生长形态的发育 黑暗的。 BR被细胞表面受体激酶BAI1感知。 BR 如何 信号从质膜上的 BRI1 转导至其他细胞和 核反应仍然未知。该提案旨在获得分子 了解模式植物拟南芥中的 BR 信号通路 拟南芥，利用分子遗传学、生物化学和细胞方法 生物学。首先，我们发现BRI1受体激酶存在于一个大的 蛋白质复合物，我们假设与 BRI1 相关的其他蛋白质 受体复合物是受体功能所必需的。我们计划 使用亲和纯化鉴定与 BRI1 相关的蛋白质并 使用反向遗传和表征这些蛋白质的功能 分子方法。二、我们已经隔离并进行了初步的 新的 BR 信号突变体 bzr1-1 D 和相应基因 BZR1 的研究。 基于这些研究，我们假设 BZR1 发挥着积极的作用 BRI1 下游 BR 反应途径的调节因子。我们计划进一步 通过鉴定 bzrl 和 的功能丧失等位基因来表征 BZR1 基因 bzr2，通过分析 BZR1 与 BR 信号传导其他基因的相互作用 途径，并通过测定 BZR1 蛋白的生化活性。我们 还计划鉴定和表征 BZR1 相互作用蛋白并执行 抑制或增强基因内和基因外突变的遗传学研究 bzr1 -1 D 突变体表型。最后，我们进行了筛查和隔离 与 BR 信号传导相关的其他突变体。我们已经克隆了基因 对应于其中一个突变体 BZR6，它编码一种小蛋白质。我们 假设 BZR6 可能作为拮抗 BR 的肽配体发挥作用 信令或作为 BR 响应的辅助信号之一。我们计划 确定 BZR6 及其同源物 BZL1 的功能。