Optogenetic engineering to probe the molecular choreography of STIM1-mediated cell signaling.
                            
                                blue
                            
                            
                                AsLOV2
                            
                                CRY2/CIB1
                            
                                iLID
                            
                            
                                
                                    Cos-7
                                
                            
                                
                                    HEK293
                                
                            
                                
                                    HeLa
                                
                            
                            
                                Signaling cascade control
                            
                                Immediate control of second messengers
                            
                            
                            
                            
                            
                        
                        
                        
                        
                            Abstract:
                            Genetically encoded photoswitches have enabled spatial and temporal control of cellular events to achieve tailored functions in living cells, but their applications to probe the structure-function relations of signaling proteins are still underexplored. We illustrate herein the incorporation of various blue light-responsive photoreceptors into modular domains of the stromal interaction molecule 1 (STIM1) to manipulate protein activity and faithfully recapitulate STIM1-mediated signaling events. Capitalizing on these optogenetic tools, we identify the molecular determinants required to mediate protein oligomerization, intramolecular conformational switch, and protein-target interactions. In parallel, we have applied these synthetic devices to enable light-inducible gating of calcium channels, conformational switch, dynamic protein-microtubule interactions and assembly of membrane contact sites in a reversible manner. Our optogenetic engineering approach can be broadly applied to aid the mechanistic dissection of cell signaling, as well as non-invasive interrogation of physiological processes with high precision.