基于蓝细菌光敏色素的细胞光遗传学元件的构建

蓝细菌光敏色素是最近确定的存在于蓝细菌中，发挥光合作用光调控作用的四吡咯光受体，与植物光敏色素同源，由于蓝细菌多样性而存在多种蓝细菌光敏色素，从而成为设计细胞光遗传学元件的良好模型。光遗传学是最近发展起来的新兴学科，它主要研究如何将光控开关蛋白与调控因子融合，转入一生物体，从而赋予该生物体新的光响应特征。本项目将从集胞蓝细菌PCC6803光敏色素设计成功的红光-绿光光控开关（RGS）入手，设计出适合于光遗传学的RGS系列高效光控开关，通过分子设计将它与腺苷环化酶融合，构建能光控开关腺苷环化酶活性的光遗传学元件。将设计的光遗传学元件转入微生物细胞或动物细胞，从而赋予该细胞崭新的光遗传学规律。该研究将构建崭新的基于RGS的光遗传学元件，特别由于蓝细菌光敏色素具有多种光响应光谱范围，从而能设计出多种光谱范围的光遗传学元件。该研究将对光遗传学和光生物学发展具有重要意义。

Cyanobacteriochromes are linear tetrapyrrole photoreceptors characterized recently in cyanobacteria, homologous to plant phytochromes, and play important roles in the photoregulation of cyanobacterial photosynthesis. Because the variations of cyanobacteria, there are various groups of cyanobacteriochromes absorbing at different wavelengths, cyanobacteriochomes become excellent templates to design cellular optogenetic units. Optogenetics is a new interdisciplinary field, usually studying how to design and fuse one photoswitchable protein with regulator to yield a new optogenetic unit. After transforming the optogenetic unit into a kind of cells, the transformed cells will be endued a designed photoregulated character. We plan to evolve molecularly the red-green photoswitchable protein (RGS) that is newly found from Synechocystis PCC 6803, to design series of highly efficient photoswitchable proteins. After designing and fusing the RGS derivatives with adenylyl cyclase, new types of optogenetic units will be designed that can photoregulate the activity of adenylyl cyclase and become suitable to optogenetics. When the designed optogenetic unit is transformed into certain cells (e.g. microbial cells), which would be endued the new optogenetic character. The studies will yield new kind of optogenetic units designed from cyanobacteriochromes. Because cyanobacteriochromes have various spectra, new optogenetic units of various spectra will be designed, which is very important to the developments of optogenetics and photobiology.