Molecular Characterization of the Ethylene Receptor ETRI from Arabidopsis

9513463 Bleecker气体激素乙烯在高等植物中调节许多重要的发育过程。 最初的生化事件参与乙烯感知正在研究中的植物拟南芥。 植物中的ETR1基因编码与细菌的感觉受体蛋白具有序列同源性的蛋白。 ETR1基因的突变赋予显性乙烯不敏感性。 通过在酵母中表达ETR1基因并发现转化的酵母将乙烯结合到ETR1蛋白质上，证实了由ETR1编码的蛋白质作为乙烯受体的作用。 使用酵母表达系统，将表达改变形式的ETR1蛋白，以研究结合和信号转导的机制。 使用体外诱变，蛋白质的单个氨基酸残基中的特定变化的影响将通过分析改变的蛋白质在转基因酵母中表达时结合乙烯的能力和抑制乙烯信号转基因植物来跟踪。 结合其他来源资助的从酵母中纯化ETR1蛋白的工作，拟议的研究将用于构建这种植物激素受体作用机制的分子模型。 此外，本研究中鉴定的ETR1基因的新突变形式将为生物技术人员提供在经济上重要的植物物种中进行乙烯敏感性遗传工程改变的能力。 ***

9513463 Bleecker The gaseous hormone ethylene regulates a number of important developmental processes in higher plants. The initial biochemical events involved in ethylene perception are being investigated in the plant Arabidopsis thaliana. The ETR1 gene in the plant codes for a protein with sequence homology to sensory receptor proteins of bacteria. Mutations in the ETR1 gene confer dominant insensitivity to ethylene. The role of the protein coded by ETR1 as an ethylene receptor was confirmed by expressing the ETR1 gene in yeast and finding that the transformed yeast binds ethylene to the ETR1 protein. Using the yeast expression system, altered forms of the ETR1 protein will be expressed to investigate the mechanism of binding and signal transduction. Using in vitro mutagenesis, effects of specific changes in single amino acid residues of the protein will be followed by analysis of the ability of the altered protein to bind ethylene when expressed in transgenic yeast, and to transduce the ethylene signal transgenic plants. In conjunction with work funded by other sources on the purification of the ETR1 protein from yeast, the proposed research will be used to construct a molecular model for the mechanism of action of this plant hormone receptor. In addition the novel mutant forms of the ETR1 gene identified in this study will provide biotechnologists with the ability to genetically engineer alterations in ethylene sensitivity in economically important plant species. ***