MOLECULAR MECHANISMS OF PHYTOCHROME SIGNALING

光敏色素信号传导的分子机制

• 批准号: 8775234
• 负责人: JOHN CLARK LAGARIAS
• 金额: $ 32.9万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-05 至 2015-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8775234
• 关键词: Address; Agriculture; Arabidopsis; Architecture; Bacteria; Behavior; Bilin; Biochemical; Biological; Biology; Biophotonics; Brown Algae; Cell Nucleus; Characteristics; Comparative Biochemistry; Coupling; Cryptophyta; Cyanobacterium; Cyanophora paradoxa; Detection; Development; Diatoms; Disease; Distant; Environment; Enzymatic Biochemistry; Evolution; Experimental Designs; Flowers; Food; Gene Expression; Genome; Germination; Grant; Green Algae; Harvest; Health; Human; Investigation; Knowledge; Left; Life; Light; Malnutrition; Mediating; Medicine; Modeling; Molecular; Molecular Biology; Molecular Genetics; Mouse-ear Cress; Nuclear; Nuclear Translocation; Organelles; Organism; Output; Pathway interactions; Perception; Phosphotransferases; Photochemistry; Photoreceptors; Phytochrome; Plants; Population; Process; Protein Biochemistry; Protein Family; Proteins; Proteobacteria; Research; Rice; Role; Scheme; Seedling; Seeds; Sexual Development; Signal Transduction; Spectrum Analysis; Structure; Sunlight; Synthesis Chemistry; System; Testing; Tetrapyrroles; Translations; Triticum aestivum; Wheat; Work; base; burden of illness; chromophore; circadian pacemaker; comparative; density; disability; fundamental research; fungus; human mortality; improved; in vivo; innovation; insight; next generation; nutrition; optogenetics; reproductive development; response; sensor; tool; transmission process

DESCRIPTION (provided by applicant): This project, entitled "Molecular Mechanisms of Phytochrome Signaling" (PI J. Clark Lagarias, UC Davis), focuses on gaining fundamental knowledge about the phytochrome family of protein light sensors. Phytochromes utilize linear tetrapyrroles (bilins) as chromophores to sense light quality, quantity and duration. Photochemical light sensing triggers conformational changes that modulate the behavior of living systems via target molecules that regulate downstream transcriptional cascades. The proposed investigations address the hypothesis that the fundamental mechanism of light sensing has remained conserved throughout billions of years of evolution since endosymbiotic capture of a cyanobacterium by a eukaryotic host. There are three specific aims focused on conservation of photoconversion and protein-chromophore interactions in plant and cyanobacterial phytochromes, the evolutionary genesis of plant phytochrome, and phytochrome photoconversion and signaling activity in land plants. By examining phytochromes from evolutionarily distant species ranging from cyanobacteria to plants, our studies seek to elucidate the basis of light sensing and the intramolecular structural changes that are used to control gene expression. Phytochromes from the glaucophyte Cyanophora paradoxa, the chlorophyte Micromonas pusilla, and the land plants Arabidopsis thaliana and Triticum aestivum (wheat), will be used to examine the hypothesis that light-regulated conformational change triggers translocation to the nucleus in all extant eukaryotic phytochromes. To test these hypotheses, we leverage computational analyses to guide experimental design, protein biochemistry and molecular biology to express and purify photoreceptors, enzymology and spectroscopy to understand light-induced changes in photoreceptor structure, and in vivo assessment of nuclear translocation and function in the model land plant Arabidopsis thaliana. Significance. Studies on phytochromes provide fundamental knowledge about how living systems regulate their behavior in response to the external environment. Phytochromes are key regulators for triggering seed germination, initiating early development of the seedling, and inducing flowering (sexual development). Because of their role in shade sensing, phytochromes are an important limiting factor for yield at high crop densities in modern agriculture. Application of the insights from our studies can improve nutrition, enhancing health, lengthening life, and reducing the burdens of illness and disability. Moreover, photosensory proteins are valuable tools for studying function and localization of mammalian proteins (optogenetics), and this work yields new tools for fundamental research into such systems.

描述（由申请人提供）：该项目的标题为“植物色素信号的分子机制”（Pi J. Clark Lagarias，UC Davis），重点侧重于获得有关蛋白质光传感器植物色系的基本知识。植物色素利用线性四吡咯（Bilins）作为发色团来感知光质量，数量和持续时间。光化学光传感会触发构象变化，从而通过调节下游转录级联反应的目标分子来调节生活系统的行为。拟议的研究涉及以下假设：自从真核宿主对蓝细菌捕获蓝细菌以来，光传感的基本机制在数十亿年的进化中一直保持保存。有三个特定的目的集中在植物和蓝细菌植物色素中的光转化和蛋白质 - 附加体相互作用，植物植物色素的进化起源以及植物植物中植物色素光转化和信号活性。通过检查从蓝细菌到植物的进化较远的物种的植物色素，我们的研究试图阐明光感应的基础和用于控制基因表达的分子内结构变化。来自青光眼氰基悖论的植物色素，叶绿素微细胞和陆地植物植物拟南芥塔利亚纳和小麦菌（小麦）将用于研究以下假设，该假设是光构象的变化触发触发到所有扩展的phytototic eukaryotic eukaryotic phytarryotic phytarryotic phytarry phytarrary phytarrary phytarrary phytrot。为了检验这些假设，我们利用计算分析来指导实验设计，蛋白质生物化学和分子生物学来表达和净化光感受器，酶学和光谱学以了解光感受器结构的光变化，以及在模型陆地植物拟南芥中的核转运和在体内评估的变化。意义。关于植物色素的研究提供了有关生活系统如何根据外部环境调节其行为的基本知识。植物色素是触发种子发芽，启动幼苗早期发育和诱导开花（性发育）的关键调节剂。由于它们在阴影传感中的作用，植物色素是现代农业高作物密度的重要限制因素。应用我们的见解 研究可以改善营养，改善健康，延长寿命并减轻疾病和残疾负担。此外，光感蛋白是研究哺乳动物蛋白（光遗传学）功能和定位的宝贵工具，这项工作为对此类系统的基础研究提供了新的工具。