Thiol-based Redox Control of Tetrapyrrole Metabolism: Posttranslational Control of Tetrapyrrole Biosynthesis Enzymes by NADPH-Dependent Thioredoxin Reductase C (NTRC) and Thioredoxins

四吡咯代谢的基于硫醇的氧化还原控制：NADPH 依赖性硫氧还蛋白还原酶 C (NTRC) 和硫氧还蛋白对四吡咯生物合成酶的翻译后控制

• 批准号: 251911153
• 负责人: Professor Dr. Bernhard Grimm
• 金额: --
• 依托单位: Arbeitsgruppe Pflanzenphysiologie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/251911153?language=en
• 关键词: Thiol; based; Redox; Control; Tetrapyrrole

Plants effectively coordinate the photosynthesis dependent production of energy and reducing equivalents with the activity of metabolic pathways. As the redox state of chloroplasts changes in dependency to photosynthesis activities, it is proposed that the dark suppression and light activation of 5-aminolevulinic acid (ALA) synthesis is coupled with redox control via modification of thiol groups of contributing enzymes. My group is interested in the elucidation of the posttranslational control of tetrapyrrole biosynthesis and we identified several enzymes of this pathway to be targets of the reversible thiol-disulfide redox regulation by the cooperative action of the redox regulators NADPH-dependent thioredoxin reductase C (NTRC) and thioredoxin (TRX). This posttranslational control mechanism balances tetrapyrrole biosynthesis in response to environmental and endogenous cues and prevents accumulation of photoreactive tetrapyrrole metabolites. In continuation we address in the follow-up proposal the two main objectives: (i) Exploration of the working hypothesis that the dark-dependent inactivation of glutamyl-tRNA reductase (GluTR) by the negative regulator FLU (FLOURESCENT) is based on a redox control mechanism and (ii) investigation of the thiol-based redox switches of two additional enzymes in the pathway, ALA dehydratase (ALAD) and protoporphyrinogen oxidase (PPOX) and elucidation of the physiological impact of the redox control on the modified activity and stability of these two target enzymes. It is expected that elucidation of these details of thiol-disulfide exchange reactions on enzymes of tetrapyrrole biosynthesis will improve understanding on redox-controlled tetrapyrrole biosynthesis, in particular the essential light-dark activation/inactivation of ALA synthesis by GluTR in higher plants.

植物有效地协调了光合作用依赖性能量的产生，并与代谢途径的活性相同。由于叶绿体的氧化还原状态对光合作用活性的依赖性变化，因此提出，5-氨基苯甲酸（ALA）合成的黑暗抑制和光激活与氧化酶的硫醇基团的修饰结合。我的小组对阐明四吡咯生物合成的翻译后控制感兴趣，我们确定了该途径的几种酶是通过氧化氧化物调节剂NADPH依赖性硫代蛋白氧蛋白还原酶（NTRX）和Thiorexin（thiorexin）（thiorexin）（thiorexin）（thiorexin）（thiorexin）（thiorexin）（thiorexin）（thiorexin）（thiorexin）（thiorexin）（thiorexin）（thiorexin）（thiorexin）（thiorexin）。这种翻译后的控制机制可以响应环境和内源性提示，平衡四吡咯的生物合成，并防止光反应性四吡咯代谢产物的积累。在延续中，我们在后续提案中解决了两个主要目标：（i）探索工作假设，即通过负调节剂（粉料）对谷氨酰基-tRNA还原酶（glutr）的黑暗依赖性灭活（hlutr）是基于氧化还原控制机制的，以及（ii）基于硫醇基于硫醇的氧化还原的dehy dehy dehroad eNzemes（ala dehox dehox nodawo）（ala）的dehox swiste（ii）（ii）。氧化还原控制对这两种靶酶的修饰活性和稳定性的生理影响阐明原生氧化氧化酶（PPOX）。可以预期，阐明这些细节对四吡咯生物合成酶的硫代二硫化物交换反应将提高人们对氧化还原对照的四吡咯生物合成的理解，特别是在较高工厂中，ALA合成的基本光滴激活/灭活。