Development of Photoactivatable Optical Bio-Sensors of Physiological Activities

Abstract

Photoactivatable fluorescent proteins enable specific localization of a region of interest by activating a small population of fluorophores. Genetically encoded fluorescent sensors of physiological activities often suffer from the high background fluorescence from a densely labeled tissue. Therefore, the development of photoactivatable variants of optical bio-sensors would facilitate accurate and targetable study by highlighting only a certain area or single cells reducing the unwanted baseline fluorescence. In this presentation, we will introduce our rational approach to develop photoactivatable versions of existing bio-sensors such as a voltage indicator or a pH indicator. We have so far constructed a circularly permuted FP, a FRET (Fluorescence Resonance Energy Transfer) pair and a cytoplasmic FP types. This includes a photoactivatable variant of our recently published genetically encoded voltage indicator, Bongwoori-R3. This variant was successfully photoactivated and its voltage sensitivity was demonstrated in mammalian cells. This research was supported by the National Institute of Neurological Disorders and Stroke of the National Institutes of Health under the award number U01NS099691.