A New Highly Efficient Molecule for Both Optogenetic and Chemogenetic Control Driven by FRET Amplification of BioLuminescence

Abstract

SignificanceBioluminescent optogenetics (BL-OG) offers a unique and powerful approach to manipulate neural activity both opto- and chemogenetically using a single actuator molecule (a LuMinOpsin, LMO). AimTo further enhance the utility of BL-OG by improving the efficacy of chemogenetic (bioluminescence- driven) LMO activation. ApproachWe developed novel luciferases optimized for Forster resonance energy transfer (FRET) when fused to the fluorescent protein mNeonGreen, generating bright bioluminescent (BL) emitters spectrally tuned to Volvox Channelrhodopsin 1 (VChR1). ResultsA new LMO generated from this approach (LMO7) showed significantly stronger BL-driven opsin activation compared to previous and other new variants. We extensively benchmarked LMO7 against LMO3 (current standard), and found significantly stronger neuronal activity modulation ex vivo and in vivo, and efficient modulation of behavior. ConclusionsWe report a robust new option for achieving multiple modes of control in a single actuator, and a promising engineering strategy for continued improvement of BL-OG.