Analysis of dynamic interactions of ROXYs, land plant-specific glutaredoxins, with TGA transcription factors during the evolution of land plants

氧化还原生物化学越来越被认为是所有类型生物体细胞信号处理的重要组成部分。目前已知，氧化剂水平的内源性变化有助于决定细胞的命运，如增殖、分化和凋亡。在氧化剂水平介导的破坏和适应过程之间保持平衡是生命形式适应不断变化的生物和非生物环境的关键，无论是在一个生物体的整个生命周期中，还是在生物进化过程中的更大范围内。植物是固着生物，与可移动的动物不同，它们必须适应面临挑战的环境，如病原体攻击造成的破坏或紫外线和干旱的胁迫暴露。所有的植物都具有CPYC和CGFS谷氧还蛋白(GRXs)，谷胱甘肽依赖的氧化还原酶蛋白，是硫氧还蛋白折叠超家族的成员。与硫氧还蛋白一样，GRX也是抗氧化剂，具有半胱氨酸硫醇二硫化物交换催化性能。大约在470年前，当植物征服陆地时，在最基本的陆地植物中出现了苔藓，一种新的陆地植物特有的GRX群，CC型GRX。在陆地植物的演化过程中，这种CC型GRX群的强烈扩张与植物的形成相吻合，植物由更复杂的器官组成，更好地适应陆地生活。这引发了关于陆地植物进化过程中新的氧化还原信号事件和硫醇开关的生物化学及其特定功能的有趣问题。拟议的SPP项目重点研究陆地植物特有的CC型GRXs、roxys和潜在的蛋白质硫醇开关在陆地植物进化过程中的功能。拟南芥的ROXY1通过与细胞核中的TGA转录因子PERIANTHIA(PAN)相互作用来控制花瓣和花药的发育。鉴于roxys是陆地植物特有的，我们的目标是揭开祖先roxys在一种基础陆地植物--多态苔藓中的分子功能，以了解陆地植物特有的一组GRX以及相关的硫醇开关和氧化还原过程如何促进对陆地生活的新适应。我们证明了roxys和TGA之间的蛋白质相互作用以及它们依赖于氧化还原的DNA结合是高度保守的。我们的目的是比较拟南芥(ROXY1，PAN)和马钱草(MpROXY1/2，MpTGA1/2)中的roxys和TGA的生化活性。通过体外和体内相结合的方法，我们的目标是更详细地分析所确定的核硫醇开关，并研究核氧化还原过程如何有助于使陆地生活方式成为可能的适应。

Redox biochemistry is increasingly recognized as a crucial component of cellular signal processing in all types of organisms. Endogenous changes of oxidant levels are now known to contribute to cell fate decisions, such as proliferation, differentiation and apoptosis. Keeping the balance between damaging and adaptive processes mediated by oxidant levels is key to adaptation of life forms to changing biotic and abiotic environments, both throughout the life cycle of one organism and also on a larger scale during the evolution of organisms. Plants are sessile organisms and, in contrast to mobile animals, have to adjust to their environment being faced with challenges such as damage by pathogen attack or stress exposure by UV-light and draught. All plants possess CPYC and CGFS glutaredoxine (GRXs), glutathione-dependent oxidoreductase proteins, which are members the thioredoxin-fold superfamily. Like thioredoxins, GRXs act as antioxidants and have cysteine thiol disulphide exchange catalytic properties. At the time when plants conquered the land, about 470 MY ago, in the most basal land plants, the mosses, a novel land plant-specific GRX group, the CC-type GRXs, emerged. During the evolution of land plants, exclusively this CC-type GRX group expanded strongly coinciding with the formation of plants, which are composed of more complex organs and better adapted to a life on land. This raises the intriguing questions about the biochemistry of novel evolving redox signaling events and thiol switches and their specific functions during the evolution of land plants.The proposed SPP project focuses on investigating the function of the land plant-specific CC-type GRXs, ROXYs, and the underlying protein thiol switches during land-plant evolution. ROXY1 from Arabidopsis thaliana governs petal and anther development via interaction with the TGA transcription factor PERIANTHIA (PAN) in the nucleus. Given that ROXYs are land-plant specific, we aim to unravel the molecular function of ancestral ROXYs in a basal land plant, the livermoss Marchanita polymorpha, to understand how a land-plant specific group of GRXs and the associated thiol-switches and redox-processes have contributed to novel adaptations to a life on land. We showed that the protein interactions between ROXYs and TGAs as well as their redox-dependent DNA binding is highly conserved. We aim to compare the biochemical activities of ROXYs and TGAs from Arabidopsis (ROXY1, PAN) and Marchantia (MpROXY1/2, MpTGA1/2). By a combination of in vitro and in vivo approaches we aim to analyzed the determined nuclear thiol-switch in more detail and investigate how nuclear redox-processes contributed to the adaptations that made a terrestrial lifestyle possible.