Department of Biochemistry and Molecular Biology and Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL 60637, USA.
Photochem Photobiol Sci. 2010 Oct 28;9(10):1286-300. doi: 10.1039/c0pp00167h. Epub 2010 Sep 13.
Cellular processes and indeed the survival of entire organisms crucially depend on precise spatiotemporal coordination of a multitude of molecular events. A new tool in cell biology is denoted "optogenetics" which describes the use of genetically encoded, light-gated proteins, i.e. photoreceptors, which perturb and control cellular and organismal behavior in a spatiotemporally exact manner. Photoreceptors resemble fluorescent reporter proteins such as GFP in being genetically encoded, non-invasive, and applicable to intact cells and organisms. They are explicitly intended to modulate activity; in contrast, fluorescent proteins generally do not disturb the processes under study. Fluorescent proteins have revolutionized cell biology because they allow the monitoring of such processes by imaging techniques that offer superb spatiotemporal resolution and sensitivity. Optogenetics extends these advantages to offer control. The scope of optogenetics has recently been expanded beyond the use of naturally occurring photoreceptors by the biologically-inspired design of engineered (or synthetic) photoreceptors. These photoreceptors are derived by fusion of one or more light-absorbing sensor domains with an output or effector domain displaying the activity to be controlled. Here, we focus on the design and application of such engineered photoreceptors. We treat basic signaling principles and discuss the two photosensor classes which are currently most widely used in fusion-based design: LOV domains and phytochromes. Based on these principles, we develop general strategies for the engineering of photoreceptors. Finally, we review recently successful examples of the design and application of engineered photoreceptors. Our perspective provides guidelines for researchers interested in developing and applying novel optogenetic tools.
细胞过程，甚至整个生物体的存活，都严重依赖于众多分子事件的精确时空协调。细胞生物学中的一种新工具被称为“光遗传学”，它描述了使用遗传编码的、光门控的蛋白质，即光感受器，以精确的时空方式干扰和控制细胞和生物体的行为。光感受器类似于荧光报告蛋白，如 GFP，它们是遗传编码的、非侵入性的，适用于完整的细胞和生物体。它们的设计目的是明确调节活性；相比之下，荧光蛋白通常不会干扰正在研究的过程。荧光蛋白彻底改变了细胞生物学，因为它们允许通过成像技术来监测这些过程，这些技术提供了极好的时空分辨率和灵敏度。光遗传学通过生物启发设计的工程（或合成）光感受器扩展了这些优势，提供了控制能力。光遗传学的范围最近已经扩展到了使用天然存在的光感受器之外，通过融合一个或多个光吸收传感器结构域与一个显示待控制活性的输出或效应器结构域，来设计工程（或合成）光感受器。在这里，我们专注于这些工程光感受器的设计和应用。我们讨论了基本的信号传递原理，并介绍了目前在融合设计中使用最广泛的两种光传感器类： LOV 结构域和光敏色素。基于这些原理，我们开发了用于工程光感受器的一般策略。最后，我们回顾了最近设计和应用工程光感受器的成功案例。我们的观点为有兴趣开发和应用新型光遗传学工具的研究人员提供了指导。
