Regulation of Tetrapyrrole Synthesis in Developing Chloroplasts

叶绿体发育过程中四吡咯合成的调控

• 批准号: 8905814
• 负责人: Paul Castelfranco
• 金额: $ 6.5万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-07-15 至 1992-02-26
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8905814&HistoricalAwards=false
• 关键词: Regulation; Tetrapyrrole; Synthesis; Developing; Chloroplasts

This research will examine chloroplastic ALA synthesis as a heterogenous phenomenon, whereby, two ALA-forming systems must be present, one of which makes ALA that is destined to protochlorophyllide (Pchlide), while the other fills up a pool that does not contribute to the Pchlide pathway and that could possibly be involved in heme synthesis. This study will identify one ALA pool as the precursor of Pchlide and the other ALA pool as the precursor of protoheme. Therefore, it will be proven that the branching point between the Mg and the Fe tetrapyrroles is not located at protoporphyrin, as generally thought, but at the synthesis of ALA itself.%%% For a number of years it has been axiomatic that the coarse control of chlorophyll synthesis lies at the level of 5- aminolevulinic acid (ALA). ALA synthesis is the crucial point in the regulation of chlorophyll as well as the pyrrole compounds. This study approaches the regulation of ALA from a physiological perspective but using biochemical tools. The relationship between the various metabolites that are formed from ALA in developing photosynthetic tissue will be determined.***//

本研究将研究叶绿体ALA合成作为一种异质现象，即必须存在两种ALA形成系统，其中一种生成注定要生成原叶绿内酯（Pchlide）的ALA，而另一种则填充一个不参与Pchlide途径且可能参与血红素合成的库。本研究将确定一个ALA池作为Pchlide的前体，另一个ALA池作为protoheme的前体。因此，将证明Mg和Fe四吡啶之间的分支点并不像通常认为的那样位于原卟啉上，而是位于ALA本身的合成上。多年来，人们一直认为叶绿素合成的粗略控制在5-氨基乙酰丙酸（ALA）水平上。ALA的合成是调节叶绿素和吡咯化合物的关键。本研究从生理角度探讨ALA的调节，但使用生化工具。在发育中的光合组织中，ALA形成的各种代谢物之间的关系将被确定