Interplay of Light, Redox Potential and Temperature in Light-Oxygen-Voltage Receptors

光氧电压受体中光、氧化还原电位和温度的相互作用

• 批准号: 420423318
• 负责人: Professor Dr. Andreas Möglich
• 金额: --
• 依托单位: Arbeitsgruppe Biochemie I
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/420423318?language=en
• 关键词: Interplay; Light; Redox; Potential; Temperature

Sensory photoreceptors endow organisms with sensitivity to light, and they double as genetically encodable actuators in optogenetics for the precise control by light of cellular physiology. Light-oxygen-voltage (LOV) photoreceptors absorb blue light by flavin nucleotides to trigger a canonical photocycle which entails formation of a thioether bond between a strictly conserved cysteine residue and the flavin chromophore. Lacking this cysteine, LOV receptors exhibit enhanced fluorescence and generation of reactive oxygen species (ROS); unexpectedly, cysteine-devoid LOV receptors are capable of downstream signal transduction via blue-light-induced formation of a flavin neutral sem-iquinone radical state. Against this backdrop, we will elucidate the interplay of various inputs (light, temperature and redox potential) and outputs (fluorescence, ROS production, signal transduction) in both cysteine-containing and cysteine-free LOV receptors. Spectroelectrochemical, biochemical and structural analyses will identify molecular determinants governing these processes, in turn allowing the rational construction of enhanced receptors with optimized signal response and minimized side reactivity. By grafting sensitivity to signals other than light onto LOV receptors, novel, precisely con-trollable cellular circuits can be devised. The natural repertoire of proteins comprises multiple entries with significant homology to LOV receptors but lacking one or several normally conserved residues. Mechanistic insight stemming from an in-depth characterization of these putative receptors will fur-ther our understanding of the increasingly multi-facetted roles of LOV receptors in Nature and stand to provide blueprints for the engineering of enhanced derivative receptors sensitive to light, redox potential and/or temperature.

感光感受器赋予生物体对光的敏感性，在光遗传学中它们也是可遗传编码的致动器，用于通过光对细胞生理进行精确控制。光-氧-电压(LOV)光感受器通过黄素核苷酸吸收蓝光，触发典型的光循环，在严格保守的半胱氨酸残基和黄素生色团之间形成硫醚键。缺乏这种半胱氨酸，LOV受体表现出增强的荧光和产生活性氧物种(ROS)；出乎意料的是，没有半胱氨酸的LOV受体能够通过蓝光诱导形成黄素中性sem-quinone自由基状态来进行下游信号转导。在此背景下，我们将阐明在含半胱氨酸和不含半胱氨酸的LOV受体中，各种输入(光、温度和氧化还原电位)和输出(荧光、ROS产生、信号转导)的相互作用。光谱电化学、生化和结构分析将确定控制这些过程的分子决定因素，进而允许合理构建增强型受体，优化信号响应并将副反应降至最低。通过将对光以外的信号的敏感度嫁接到LOV受体上，可以设计出新颖的、精确可控的细胞电路。天然蛋白质谱包括与LOV受体有显著同源性的多个条目，但缺少一个或几个正常保守的残基。对这些可能的受体进行深入的表征将有助于我们理解LOV受体在自然界中日益多方面的作用，并为设计对光、氧化还原电位和/或温度敏感的增强型衍生受体提供蓝图。