Design and engineering of light-sensitive protein switches.
                            
                                blue
                            
                                green
                            
                                near-infrared
                            
                                red
                            
                            
                                Cobalamin-binding domains
                            
                                Cryptochromes
                            
                                LOV domains
                            
                                Phytochromes
                            
                            
                            
                            Review
                            
                            
                            
                        
                        
                        
                        
                            Abstract:
                            Engineered, light-sensitive protein switches are used to interrogate a broad variety of biological processes. These switches are typically constructed by genetically fusing naturally occurring light-responsive protein domains with functional domains from other proteins. Protein activity can be controlled using a variety of mechanisms including light-induced colocalization, caging, and allosteric regulation. Protein design efforts have focused on reducing background signaling, maximizing the change in activity upon light stimulation, and perturbing the kinetics of switching. It is common to combine structure-based modeling with experimental screening to identify ideal fusion points between domains and discover point mutations that optimize switching. Here, we introduce commonly used light-sensitive domains and summarize recent progress in using them to regulate protein activity.