CAREER: Structural dynamics and mechanisms of photoreceptor signaling

光感受器使生物体能够调节对光的广泛的生物反应，包括光合作用、细胞和细胞器的运动、视觉转导和昼夜节律。这些重要的细胞介质与生物膜的形成有关，并可以改变生物体的毒力。光感受器也是光驱动设备的原型。阐明光感受器的潜在工作机制仍然是光遗传学领域发展的关键驱动力。在大多数情况下，光的吸收导致所涉及的蛋白质的化学和结构变化，最终产生生物产量。尽管进行了广泛的研究，但关于这种信号是如何传播的许多细节却知之甚少。该项目的目标是确定在特定类别的光感受器中将光吸收与下游生物过程激活相耦合的潜在分子机制。这项工作将首次使用黄素蛋白(BLUF)类蛋白质对蓝光蛋白(BLUF)类蛋白质的状态之间的动态转变进行时间分辨的分子描述，并提供结构工具，从而能够进行更高效和有效的系列结晶学实验。这个项目的教育目标是建立一个混合的研究/教育结构蛋白质组学渠道，涉及本科生和高中生群体。这一众包计划不仅将为学生群体提供机会，在受控的环境中进行实践的、真正的研究，还将利用人数的优势来解决一个具有挑战性和根本上重要的研究问题。研究和教育目标将通过并行使用X射线结晶学以及研究生在拟议工作的两个方面的参与和监督来整合。该项目的研究目标是确定驱动蓝光使用FAD(BLUF)蛋白质的结构变化和信号事件的内在分子决定因素和动态结构特征。特别是，将阐明在从暗到光转变过程中驱动信号转导的分子变化，并将确定特定BLUF受体蛋白和复合体的光诱导络合机制。这些研究将把时间分辨光谱方法与静态和动态结构表征相结合，以绘制光感受器激活过程中发生的空间和时间变化。此外，还将开发和实施一种声学中介的系列结晶学方法。这种方法将被用来生成BLUF蛋白质在信号转导过程中发生的结构变化的分子电影，并将广泛适用于在任何X射线源对广泛的样本进行有效的时间分辨结构研究的手段。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Photoreceptors enable organisms to mediate a vast range of biological responses to light, including photosynthesis, cell and organelle motility, visual transduction and circadian rhythms. These important cellular mediators are implicated in biofilm formation and can alter the virulence of organisms. Photoreceptors are also the prototype for light driven devices. Elucidating the underlying mechanisms of operation of photoreceptors remain a key driver for the development of the field of optogenetics. In most cases, the absorption of light results in chemical and structural changes of the proteins involved that ultimately produce the biological output. Despite extensive studies, many of the details of how this signal is propagated are poorly understood. The objective of this project is to determine the underlying molecular mechanisms that couple light absorption to the activation of downstream biological processes in a specific class of photoreceptors. This work will generate the first time-resolved molecular description of the dynamic transition between states for the Blue Light Using Flavoprotein (BLUF) class of proteins and by providing structural tools that will enable more efficient and effective serial crystallography experiments. The educational objective of this project is to generate a hybrid research/educational structural proteomics pipeline, involving groups of undergraduates and high school students. This crowd-sourcing program will not only provide an opportunity for groups of students to conduct hands-on, 'real' research in a controlled setting, but will leverage the strength in numbers to address a challenging and fundamentally important research problem. The research and educational objectives will be integrated through their parallel use of X-ray crystallography and through graduate student involvement and oversight in both aspects of the proposed work.The research objective of this project is to determine the intrinsic molecular determinants and dynamic structural features that drive structural changes and signaling events in blue-light using FAD (BLUF) proteins. In particular, the molecular changes that drive signal transduction during the dark to light transition will be elucidated and the mechanism of photo-induced complexation of specific BLUF receptor proteins and complexes will be determined. These studies will integrate time-resolved spectroscopic methods with static and dynamic structural characterization to map the spatial and temporal changes that occur during photoreceptor activation. In addition, an acoustically-mediated serial crystallography approach will be developed and implemented. This approach will be used to generate molecular movies of the structural changes that occur during signal transduction in BLUF proteins and will be broadly applicable as a means to conduct efficient time-resolved structural studies on a broad range of samples at any X-ray source.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.