Bradley Baker, Ph.D., Principal Scientist, Brain Science Institute, Korea Institute of Science and Technology, will present a lecture entitled: Using GEVIs to map neuronal activity, visualize molecular switches, and demonstrate the influence of lipid domains on protein function.
Abstract: Genetically encoded voltage indicators (GEVIs) enable the optical resolution of neuronal activities from multiple locations simultaneously. Given their ability to rapidly transition between fluorescent states, GEVIs also offer novel insights into the mechanism causing fluorescence change. In addition, altering
their voltage dependence has revealed novel effects lipid domains in the plasma membrane have on the voltage-sensitivity of the protein. In this presentation, I will relate our efforts to map neuronal activities in retinal preparations with examples of both chemical and electrical synapses from single cell excitation. In an effort to improve the signal-to-noise ratio of GEVIs, we have discovered that internal
threonine sidechains near the chromophore of the fluorescent protein domain can be controlled to mediate fluorescence change in response to environmental conditions: a threonine switch. Exploring the voltage-sensitivity of the GEVI also revealed that lipid domains in the plasma membrane can influence the voltage-dependent optical signal. With these new insights, we hope to develop better biosensors for a wide range of physiological measurements including membrane tension/lipid rafts as well as voltage. We should also be able to expand the repertoire of these sensors to different wavelengths as these observations should also apply to any fluorescent protein with a β-can structure