cn9b00501_si_001.pdf (1.92 MB)
Imaging Neuronal Activity with Fast and Sensitive Red-Shifted Electrochromic FRET Indicators
journal contribution
posted on 2019-11-21, 13:03 authored by Yongxian Xu, Mengying Deng, Shu Zhang, Junqi Yang, Luxin Peng, Jun Chu, Peng ZouGenetically encoded voltage indicators (GEVIs) allow
optical recording of neuronal activities with high spatial resolution.
While most existing GEVIs emit in the green range, red-shifted GEVIs
are highly sought after because they would enable simultaneous stimulation
and recording of neuronal activities when paired with optogenetic
actuators, or two-color imaging of signaling and neuronal activities
when used along with GFP-based indicators. In this study, we present
several improved red-shifted GEVIs based on the electrochromic Förster
resonance energy transfer (eFRET) between orange/red fluorescent proteins/dyes
and rhodopsin mutants. Through structure-guided mutagenesis and cell-based
sensitivity screening, we identified a mutant rhodopsin with a single
mutation that exhibited more than 2-fold improvement in voltage sensitivity.
Notably, this mutation has been independently discovered by Pieribone et
al. (Pieribone, V. A. et al. Nat Methods 2018, 15 (12), 1108−1116). In cultured rat hippocampal neurons, our sensors faithfully reported
action potential waveforms and subthreshold activities. We also demonstrated
that this mutation could enhance the sensitivity of hybrid indicators,
thus providing insights for future development.