A Photoactivatable Botulinum Neurotoxin for Inducible Control of Neurotransmission.
                            
                                blue
                            
                            
                                CRY2/CIB1
                            
                                iLID
                            
                            
                                
                                    C. elegans in vivo
                                
                            
                                
                                    HEK293T
                                
                            
                                
                                    primary rat hippocampal neurons
                                
                            
                            
                                Control of intracellular / vesicular transport
                            
                                Neuronal activity control
                            
                            
                            
                            
                            
                        
                        
                        
                        
                            Abstract:
                            Regulated secretion is critical for diverse biological processes ranging from immune and endocrine signaling to synaptic transmission. Botulinum and tetanus neurotoxins, which specifically proteolyze vesicle fusion proteins involved in regulated secretion, have been widely used as experimental tools to block these processes. Genetic expression of these toxins in the nervous system has been a powerful approach for disrupting neurotransmitter release within defined circuitry, but their current utility in the brain and elsewhere remains limited by lack of spatial and temporal control. Here we engineered botulinum neurotoxin B so that it can be activated with blue light. We demonstrate the utility of this approach for inducibly disrupting excitatory neurotransmission, providing a first-in-class optogenetic tool for persistent, light-triggered synaptic inhibition. In addition to blocking neurotransmitter release, this approach will have broad utility for conditionally disrupting regulated secretion of diverse bioactive molecules, including neuropeptides, neuromodulators, hormones, and immune molecules. VIDEO ABSTRACT.