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细胞信号处理的重要组成部分。现在已知内源性氧化剂水平的变化有助于细胞命运的决定，如增殖、分化和凋亡。维持由氧化剂水平介导的破坏和适应过程之间的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，还是在生物体进化的更大范围内。植物是无根的生物，与移动的动物不同，植物必须适应环境，面对诸如病原体攻击的损害或紫外线和干旱的应激暴露等挑战。所有植物都含有谷胱甘肽依赖的氧化还原酶蛋白CPYC和CGFS glutaredoxine (GRXs)，它们是硫氧还蛋白折叠超家族的成员。与硫氧还毒素一样，GRXs具有抗氧化剂的作用，并具有半胱氨酸硫醇二硫交换催化性能。大约470年前，当植物征服陆地时，在最基础的陆地植物苔藓中，出现了一种新的陆地植物特异性GRX群，即cc型GRX。在陆地植物的进化过程中，只有这一cc型GRX类群在植物形成的同时迅速扩张，而植物则由更复杂的器官组成，更能适应陆地生活。这就提出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及其特定功能的生物化学问题。拟建的SPP项目重点研究陆地植物特异性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。来自拟南芥的ROXY1通过与核中TGA转录因子花被（PAN）的相互作用来控制花瓣和花药的发育。鉴于ROXYs是陆生植物特异性的，我们的目标是揭示陆生植物Marchanita polymorpha中祖先ROXYs的分子功能，以了解陆生植物特异性grx群及其相关的硫醇开关和氧化还原过程如何促进对陆地生命的新适应。我们发现ROXYs和TGAs之间的蛋白质相互作用以及它们的氧化还原依赖的DNA结合是高度保守的。我们的目的是比较拟南芥（ROXY1， PAN）和苋（MpROXY1/2, MpTGA1/2）中ROXYs和TGAs的生化活性。通过体外和体内方法的结合，我们的目标是更详细地分析确定的核硫醇开关，并研究核氧化还原过程如何促进适应，使陆地生活方式成为可能。

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.