Molecular Light Switch for Controlled Gene Expression

描述（由申请人提供）：基因表达的实验操作是一种广泛使用的技术，对许多现代生物医学研究至关重要。控制重组基因的时机和表达水平的能力对于生产用于基础研究的重组蛋白以及用于生物药物的合成至关重要。用于控制哺乳动物细胞中基因表达的市售系统，无论是在实验室培养物中还是在整个动物中，都依赖于小分子药物的应用来诱导或抑制转录。这些系统受到若干限制，包括毒性、脱靶效应、缺乏与时间和位置相关的精确性以及诱导的可逆性。此外，效应药物和必要的无药物培养基的成本可能是负担的。需要新技术来克服这些限制。 目前的项目旨在开发一种使用长波长（700-750 nm）光诱导控制基因表达的新系统。除了避免与基于药物的系统相关的副作用和成本之外，光诱导控制还提供了精确的个体组织和细胞的空间和时间靶向的优点。光还避免了基于小分子的诱导剂中固有的摄取和运输要求。我们提出的策略将利用一种对长波长光有天然反应的感光器类别，并将其转换为 转化为控制靶基因转录的“分子光开关”。所选择的光感受器也是天然光可逆的，使得工程化的转录开关能够发挥前所未有的转录控制水平。该系统的成功开发不仅有可能彻底改变哺乳动物细胞培养中的诱导型基因表达，而且还可能推进整个动物中转基因表达的研究和新型遗传疗法的开发。

DESCRIPTION (provided by applicant): Experimental manipulation of gene expression is a widely used technique that is crucial to much of modern biomedical research. The ability to control the timing and expression level of recombinant genes is central to the production of recombinant protein for basic research as well as for the synthesis of biological pharmaceuticals. Commercially available systems for controlling gene expression in mammalian cells, whether in laboratory cultures or in whole animals, are dependent on the application of small molecule drugs to induce or repress transcription. These systems suffer from several limitations, including toxicity, off-target effects, lack of precision in relation to timing and loation, and reversibility of induction. Moreover, the cost of the effector drug and necessary drug-free media can be burdensome. New technologies are needed to overcome these limitations. The current project aims to develop a new system for inducible control of gene expression using long-wavelength (700-750 nm) light. In addition to avoiding the side effects and costs associated with drug-based systems, light-inducible control offers the advantages of precise spatial and temporal targeting of individual tissues and cells. Light also avoids the uptake and transport requirements inherent in small molecule-based inducers. Our proposed strategy will exploit a photoreceptor class that is naturally responsive to long-wavelength light, and convert it into a "molecular light switch" that controls transcription of target genes. The selected photoreceptor is also naturally photoreversible enabling the engineered transcriptional switch to exert an unprecedented level of transcriptional control. Successful development of this system has the potential not only to revolutionize inducible gene expression in mammalian cell culture, but is also likely to advance the study of transgenic expression in whole animals and the development of novel genetic therapies.