title: Optical control of mammalian endogenous transcription and epigenetic states.
abstract: 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.
authors.affiliation: Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA.|McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Silvana
authors.initials: S
authors.lastname: Konermann
authors.affiliation: Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA.|McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.|School of Engineering and Applied Sciences, Harvard University Cambridge, MA 02138, USA.
authors.forename: Mark D
authors.initials: MD
authors.lastname: Brigham
authors.affiliation: Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA.|McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Alexandro
authors.initials: A
authors.lastname: Trevino
authors.affiliation: Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA.|McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.|Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA.
authors.forename: Patrick D
authors.initials: PD
authors.lastname: Hsu
authors.affiliation: Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA.|McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Matthias
authors.initials: M
authors.lastname: Heidenreich
authors.affiliation: Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA.|McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.|Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA.
authors.forename: Le
authors.initials: L
authors.lastname: Cong
authors.affiliation: Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA.|McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Randall J
authors.initials: RJ
authors.lastname: Platt
authors.affiliation: Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA.|McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Scott
authors.affiliation: Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA.|Department of Genetics, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: George M
authors.initials: GM
authors.lastname: Church
authors.affiliation: Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA.|McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Feng
authors.initials: F
authors.lastname: Zhang
mesh_terms: D000818:Animals; D029681:Arabidopsis Proteins / Q000378:metabolism; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism; D002478:Cells, Cultured; D002843:Chromatin / Q000235:genetics / Q000528:radiation effects; D056931:Cryptochromes / Q000378:metabolism; D044127:Epigenesis, Genetic / Q000235:genetics* / Q000528:radiation effects*; D005786:Gene Expression Regulation / Q000235:genetics / Q000528:radiation effects*; D005822:Genetic Vectors / Q000235:genetics; D008027:Light; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000378:metabolism / Q000528:radiation effects; D062308:Optogenetics / Q000379:methods*; D013997:Time Factors; D014158:Transcription, Genetic / Q000235:genetics / Q000528:radiation effects*; D020798:Two-Hybrid System Techniques; D014851:Wakefulness
chemical_list: D029681:Arabidopsis Proteins; D051792:Basic Helix-Loop-Helix Proteins; D002843:Chromatin; D056931:Cryptochromes; C533832:CIB1 protein, Arabidopsis