Structural Biochemistry of the UVR8 Photoreceptor Signaling Pathway

智力优势：植物必须对光线等环境信号做出反应才能生存和繁荣。光传感器使植物能够通过触发光合作用、紫外线防晒保护和适当的光激活生长和发育（光形态发生）来对阳光做出反应。植物UVR8 UV-B光敏系统利用一种新型色氨酸金字塔作为固有的发色团，启动胁迫反应以促进生存，然后偶联信号相互作用引发大量基因表达变化。这种光激活系统，通过应用最先进的生物物理技术和跨学科方法进行研究，将使对原型生物反应途径的机制理解成为可能。在Getzoff实验室确定的UVR8的第一个晶体学和溶液结构的基础上，本研究将整合x射线晶体学和溶液散射的结构生物学专业知识；生物化学综合模型的建立；光谱学分析光激活机制和表型；以及与植物生物学家的战略性跨学科合作，通过植物分子遗传学来了解和了解植物。该结果将为植物生物学家提供光形态发生的分子水平评价。UVR8伴侣的鉴定将提供β -螺旋桨WD40结构域的结构、相互作用和活性信息，WD40结构域是真核生物基因组中最丰富的十大折叠之一。由此产生的对植物如何对阳光作出反应的机制理解，为了解作物如何对气候变化和大气臭氧消耗导致的辐射增加作出反应提供了见解。更广泛的影响：该项目将通过为高中生提供真正的研究经验，将科学带入课堂。这些学生在自己的实验室学习分子生物学技术，通过制造基于结构的突变体来参与；培养蛋白质晶体并看到与环境问题相关的切实成果。因此，学生积极运用科学方法，学习如何通过实验检验生物学假说。该项目将促进PI继续参与跨学科研究生课程，并支持科学、技术、工程和数学领域代表性不足的群体的参与。在实验室，学生和博士后研究员将接受培训，为跨学科的国际合作做出贡献，并指导初级实习生参与涉及UVR8植物光响应系统的项目。

Intellectual Merit:Plants must respond to environmental cues like light to survive and flourish. Light sensors enable plants to react to sunlight by triggering photosynthesis, UV sunscreen protection, and appropriate light-activated growth and development (photomorphogenesis). The plant UVR8 UV-B photoreceptive system initiates stress responses to promote survival using a novel tryptophan pyramid as the intrinsic chromophore, then couples signaling interactions to trigger massive gene expression changes. This light-activated system, investigated by the application of state-of-the-art biophysical techniques and a transdisciplinary approach will enable a mechanistic understanding of a prototypic biological response pathway. Building on the first crystallographic and solution structures of UVR8 determined in the Getzoff lab, this research will integrate structural biology expertise in X-ray crystallography and solution scattering; building of comprehensive biochemical models; spectroscopy to assay light-activated mechanisms and phenotypes; and strategic cross-disciplinary collaborations with plant biologists to inform and be informed by molecular genetics in plants. The results will provide plant biologists with a molecular-level appreciation of photomorphogenesis. Characterization of UVR8 partners will provide information on structure, interactions and activities of the beta-propeller WD40 domain, one of the top-ten most abundant folds in eukaryotic genomes. The resulting mechanistic understanding of how plants respond to sunlight provides insights into how crops will react to climate change and to increased radiation resulting from depletion of atmospheric ozone.Broader Impacts:This project will bring science into the classroom by providing genuine research experience to high school students. Learning molecular biology techniques in their own lab, these students participate by making structure-based mutants; growing protein crystals and seeing tangible outcomes relevant to environmental problems. Thus, students actively apply the scientific method and learn how to test biological hypotheses experimentally. This project will facilitate continued PI involvement in the interdisciplinary graduate program and support participation of underrepresented groups in Science, Technology, Engineering and Mathematics. In the lab, students and post-doctoral fellows will be trained in contributing to interdisciplinary, international collaborations and mentoring junior interns in projects involving the UVR8 plant photoresponse system.