Charakterisierung des PGRL1/FQR Enzyms auf genetischer, funktioneller und evolutionärer Ebene

PGRL1/FQR 酶在遗传、功能和进化水平上的表征

• 批准号: 248406100
• 负责人: Professor Dr. Dario Leister
• 金额: --
• 依托单位: Lehrstuhl für Molekularbiologie der Pflanzen
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/248406100?language=en
• 关键词: Charakterisierung; des; PGRL1; FQR; Enzyms

Whereas linear electron flow is driven by both photosystems and produces ATP and NADPH, the cyclic electron flow (CEF) only generates ATP and is driven by photosystem I alone. We recently identified PGRL1 as a central component of the antimycin A (AA)-sensitive variant of CEF and found that Arabidopsis PGRL1 is a redox-active protein which actually acts in vitro, together with PGR5, as the long sought ferredoxin-plastoquinone reductase (FQR). Interestingly, the complexity of PGRL1/PGR5-dependent CEF seems to have gradually evolved from a process that involves PGR5 (and most likely an as yet not identified protein with PGRL1-like function) in a AA-sensitive manner in Synechocystis (a model for the endosymbiont giving rise to the chloroplast), to mechanisms that rely on both proteins, either involving a PGRL1- and PGR5-containing supercomplex lacking AA-sensitivity (in Chlamydomonas, a model for unicellular organisms with chloroplasts) or as an AA-sensitive PGRL1-PGR5 heterodimer (in Arabidopsis, a model for multicellular land plants). In this project, we wish to reconstruct the evolution of the function of PGRL1 and PGR5, thereby resolving the functional discrepancies which apparently exist between land plants (Arabidopsis), green algae (Chlamydomonas) and cyanobacteria (Synechocystis). To this end, we employ the cyanobacterium Synechocystis to reconstruct and characterise the protein complexes that mediate the flowering-plant- and green-alga- types of CEF, as well as to identify the functional analogue of PGRL1 (PRIO) in Synechocystis, for the existence of which we obtained strong evidence in preliminary work. By systematically identifying and characterising suppressor mutations that can compensate the effects of the pgr5 mutation in Arabidopsis, we will dissect the interplay of the PGRL1/PGR5 pathway with other electron transport pathways in the flowering plant Arabidopsis. To achieve these goals, we will focus on seven sub-projects.

线性电子流由光系统驱动并产生ATP和NADPH，而环状电子流（CEF）仅生成ATP，并且仅由光系统I驱动。我们最近将PGRL1确定为CEF的抗霉素A（AA）敏感变体的核心成分，发现拟南芥PGRL1是一种氧化还原活性蛋白，实际上与PGR5一起起作用，与PGR5一起起作用，作为长期寻求的甲状腺素 - 磷酸固醇还原酶（FQR）。 Interestingly, the complexity of PGRL1/PGR5-dependent CEF seems to have gradually evolved from a process that involves PGR5 (and most likely an as yet not identified protein with PGRL1-like function) in a AA-sensitive manner in Synechocystis (a model for the endosymbiont giving rise to the chloroplast), to mechanisms that rely on both proteins, either involving a PGRL1- and含PGR5的超复合物缺乏AA敏感性（在衣原体中，一种具有叶绿体单细胞生物的模型）或作为AA敏感的PGRL1-PGR5异二聚体（在拟南芥中，一种用于多细胞地土地工厂的模型）。在这个项目中，我们希望重建PGRL1和PGR5功能的演变，从而解决显然存在的功能差异，这些功能差异显然存在于土地植物（拟南芥），绿藻（衣原体）和蓝藻（Synechocystis）之间。为此，我们采用蓝细菌合成细菌来重建和表征介导开花植物和绿色 - α-类型的蛋白质复合物，并识别pgrl1（prio）在合成细胞中的功能类似物，以便我们在预防性工作中揭示了强有力的证据。通过系统地识别和表征可以补偿拟南芥中PGR5突变影响的抑制突变，我们将剖析PGRL1/PGR5途径与开花植物拟南芥中其他电子传输途径的相互作用。为了实现这些目标，我们将专注于七个子项目。