Optogenetic protein clustering and signaling activation in mammalian cells.
                            
                                blue
                            
                            
                                CRY2/CRY2
                            
                            
                                
                                    HEK293T
                                
                            
                                
                                    NIH/3T3
                                
                            
                            
                                Signaling cascade control
                            
                                Control of cytoskeleton / cell motility / cell shape
                            
                            
                            
                            
                            
                        
                        
                        
                        
                            Abstract:
                            We report an optogenetic method based on Arabidopsis thaliana cryptochrome 2 for rapid and reversible protein oligomerization in response to blue light. We demonstrated its utility by photoactivating the β-catenin pathway, achieving a transcriptional response higher than that obtained with the natural ligand Wnt3a. We also demonstrated the modularity of this approach by photoactivating RhoA with high spatiotemporal resolution, thereby suggesting a previously unknown mode of activation for this Rho GTPase.