Optogenetic Inhibitor of the Transcription Factor CREB.
                            
                                blue
                            
                            
                                PYP
                            
                            
                                
                                    HEK293T
                                
                            
                                
                                    in vitro
                                
                            
                                
                                    primary mouse cortical neurons
                                
                            
                            
                                Endogenous gene expression
                            
                                Extracellular optogenetics
                            
                            
                            
                            
                            
                        
                        
                        
                        
                            Abstract:
                            Current approaches for optogenetic control of transcription do not mimic the activity of endogenous transcription factors, which act at numerous sites in the genome in a complex interplay with other factors. Optogenetic control of dominant negative versions of endogenous transcription factors provides a mechanism for mimicking the natural regulation of gene expression. Here we describe opto-DN-CREB, a blue-light-controlled inhibitor of the transcription factor CREB created by fusing the dominant negative inhibitor A-CREB to photoactive yellow protein (PYP). A light-driven conformational change in PYP prevents coiled-coil formation between A-CREB and CREB, thereby activating CREB. Optogenetic control of CREB function was characterized in vitro, in HEK293T cells, and in neurons where blue light enabled control of expression of the CREB targets NR4A2 and c-Fos. Dominant negative inhibitors exist for numerous transcription factors; linking these to optogenetic domains offers a general approach for spatiotemporal control of native transcriptional events.