Feng Zhang及同事将可定制的TALE DNA结合域与光敏“隐花色素-2”蛋白及其来自拟南芥的相互作用伙伴CIB1结合在了一起，从而生成了一个光遗传“双杂合”系统（他们将其称为LITEs，即“光可诱导的转录效应物”）。LITEs不需要其他辅因子，容易被定制来以很多位点为目标，并且还能快速地、可逆地被激活。它们还可被打包到病毒载体内，定向输送到特定细胞类群中。作者将这一系统应用到了小鼠的原代神经元中和清醒小鼠的脑中，来调制内源基因表达和定位表观染色质修饰。这一LITE系统为内源细胞过程的光遗传控制建立了一个新颖模型。（生物谷Bioon.com）
生物谷推荐英文摘要：
Nature doi: 10.1038/nature12466
Optical control of mammalian endogenous transcription and epigenetic states
Silvana Konermann, Mark D. Brigham,Alexandro E. Trevino,Patrick D. Hsu, Matthias Heidenreich,Le Cong,Randall J. Platt,David A. Scott,George M. Church & Feng Zhang
The dynamic nature of gene expression enables cellular programming, homeostasis and environmental adaptation in living systems. Dissection of causal gene functions in cellular and organismal processes therefore necessitates approaches that enable spatially and temporally precise modulation of gene expression. Recently, a variety of microbial and plant-derived light-sensitive proteins have been engineered as optogenetic actuators, enabling high-precision spatiotemporal control of many cellular functions. However, versatile and robust technologies that enable optical modulation of transcription in the mammalian endogenous genome remain elusive. Here we describe the development of light-inducible transcriptional effectors (LITEs), an optogenetic two-hybrid system integrating the customizable TALE DNA-binding domain with the light-sensitive cryptochrome 2 protein and its interacting partner CIB1 from Arabidopsis thaliana. LITEs do not require additional exogenous chemical cofactors, are easily customized to target many endogenous genomic loci, and can be activated within minutes with reversibility. LITEs can be packaged into viral vectors and genetically targeted to probe specific cell populations. We have applied this system in primary mouse neurons, as well as in the brain of freely behaving mice in vivo to mediate reversible modulation of mammalian endogenous gene expression as well as targeted epigenetic chromatin modifications. The LITE system establishes a novel mode of optogenetic control of endogenous cellular processes and enables direct testing of the causal roles of genetic and epigenetic regulation in normal biological processes and disease states.
