Molecular Characterization of the Ethylene Receptor ETR1 From Arabidopsis

拟南芥乙烯受体 ETR1 的分子表征

• 批准号: 9817311
• 负责人: Anthony Bleecker
• 金额: $ 33万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-04-01 至 2003-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9817311&HistoricalAwards=false
• 关键词: Molecular; Characterization; Ethylene; Receptor; ETR1

The plant hormone ethylene regulates many aspects of growth and development. A family of proteins that act as receptors for ethylene have been identified from Arabidopsis. This research is focused on gaining an understanding of the mechanism by which this family of receptors perceives and transduces the ethylene signal. Expression of the ETR 1 receptor protein in yeast provides a model system in which to study the structure/function relationships of the ethylene binding site. Site directed mutagenesis of the ethylene binding domain of ETR1 and assessment of effects on ethylene binding activity in yeast provides a method for testing and refining a structural model of the ethylene binding domain. Expression in yeast will also continue to provide a source of the ETR1 protein for direct biochemical analysis of receptor function, including continuing analysis of the involvement of copper as a co-factor for binding and investigations into the relationship between ethylene binding and signal output by the transmitter domain of the receptor. Co-expression of different isoforms of the receptor in the same yeast line will allow the investigation of whether heterodimerization of receptor isoforms plays a role in signaling The work in yeast will be complemented by experiments performed in mutant and transgenic plants that will provide a functional context for testing hypotheses concerning receptor function. Dominant effects of introduced mutations in receptor isoforms will be assessed by transferring altered forms of the receptor into wild-type plants and evaluating the effects on the ethylene signaling in vivo using a seedling growth-response assay. Receptor-null mutant backgrounds provide a method for evaluating the effects of recessive mutations in a similar way. Ethylene binding assays in plant tissues in the receptor-null genetic backgrounds will provide information on the contribution each isoform makes to the overall binding activity of plant tissues. These experiments will be supported by the development of isoform-specific antibodies. This research on the first available plant hormone receptor will provide novel information on how ethylene works as a hormone signal and will provide a model for the investigation of other hormone receptors in plants.

植物激素乙烯调节着生长发育的许多方面。已经从拟南芥中鉴定出一个作为乙烯受体的蛋白质家族。本研究的重点是了解该受体家族感知和转导乙烯信号的机制。ETR 1受体蛋白在酵母中的表达为研究乙烯结合位点的结构/功能关系提供了一个模型系统。酵母中ETR1的乙烯结合域的定点诱变和对乙烯结合活性影响的评估为测试和完善乙烯结合域的结构模型提供了一种方法。在酵母中的表达也将继续为受体功能的直接生化分析提供ETR1蛋白的来源，包括继续分析铜作为结合的辅助因子的参与，以及研究乙烯结合与受体递质结构域信号输出之间的关系。在同一酵母菌系中，不同受体亚型的共表达将允许研究受体亚型的异源二聚化是否在信号传导中起作用。在酵母中的工作将通过在突变体和转基因植物中进行的实验来补充，这将为测试有关受体功能的假设提供功能背景。通过将受体的改变形式转移到野生型植物中，并使用幼苗生长反应试验评估对体内乙烯信号的影响，将评估受体同种异构体引入突变的显性效应。无受体突变背景提供了一种以类似方式评估隐性突变影响的方法。在没有受体的遗传背景下，植物组织中的乙烯结合试验将提供有关每种异构体对植物组织总体结合活性的贡献的信息。这些实验将由异构体特异性抗体的发展来支持。这一首次发现的植物激素受体的研究将为乙烯作为激素信号的作用机制提供新的信息，并为植物中其他激素受体的研究提供一个模型。