EAGER: Developing Optically Triggered Protein Actuators in Living Organisms

有了这个奖项，化学部门的生命过程化学项目和分子和细胞生物科学部的细胞动力学和功能集群资助埃默里大学的哈立德·萨莱塔教授开发和表征一类新的基因编码蛋白质，这些蛋白质在光激发时产生机械力。尽管机械转导很重要，但与特定生化途径的力的大小、时间和位置有关的分子细节仍然知之甚少。这部分是由于无法控制单个蛋白质内部的机械张力。因此，力学在调节生化途径中的确切作用仍然难以测试。由Salaita教授领导的研究项目旨在解决这一限制，并帮助整合光遗传学、机械生物学和生物物理学等不断发展的领域。为了最大限度地传播研究成果，并增加机械生物学领域研究人员对新工具的采用，描述力致动器模块变体的优化和生物物理响应的方法将通过科学期刊发表，并将在即将举行的区域分子和细胞生物物理学会议的光力学会议上公开。该项目为研究生和本科生提供高度多学科的实践培训。拟议的研究重点是开发一类新的遗传编码蛋白质，当被照亮时，这些蛋白质会产生机械力。在照明后，这些“力致动器”预计会坍塌，并以高空间和时间分辨率、地点选择性和非侵入性的方式施加特定大小的张力。荧光标记力致动器的光力学性能通过稳态和时间分辨光谱方法表征。对于最初的体外研究，力致动器模块被引入到vinculin的头部和尾部之间。选择血管蛋白是因为它是局灶黏附复合物的核心蛋白，并且血管蛋白之间的张力调节一系列过程，如细胞突起和迁移。

With this award, the Chemistry of Life Processes Program of the Chemistry Division and the Cellular Dynamics and Function Cluster of the Division of Molecular and Cellular Biosciences are funding Prof. Khalid Salaita from Emory University to develop and characterize a new class of genetically-encoded proteins that exert a mechanical force when optically excited. Despite the importance of mechanotransduction, the molecular details relating the magnitude, timing, and location of forces to specific biochemical pathways remain poorly understood. This is due, in part, to the inability to control mechanical tension within individual proteins. Therefore the precise role of mechanics in regulating biochemical pathways remains difficult to test. The research program led by Prof. Salaita aims to address this limitation and to aid in the integration of the growing fields of optogenetics, mechanobiology, and biophysics. To maximize the dissemination of the research results and to increase adoption of the new tools by researchers in the area of mechanobiology, the methods describing the optimization and biophysical response of force actuator module variants are made available through publication in scientific journals and will be also made public in a session dedicated to opto-mechanics at an upcoming regional molecular and cellular biophysics meeting. The project provides highly multidisciplinary, hands-on training for graduate and undergraduate students.The proposed research focuses on the development of a new class of genetically-encoded proteins that exert a mechanical force when illuminated. Upon illumination, these "force actuators" are expected to collapse and apply a tension of specific magnitude with high spatial and temporal resolution and in a site-selective and non-invasive manner. The opto-mechanical properties of the fluorescently-tagged force actuators are characterized by steady-state and time-resolved spectroscopic methods. For initial in-vitro studies, the force actuator modules are introduced between the head and tailpiece of vinculin. Vinculin was chosen because it is a core protein within focal adhesion complexes and the tension across vinculin regulates a range of processes such as cell protrusion and migration.