Insertion of the voltage-sensitive domain into circularly permuted red fluorescent protein as a design for genetically encoded voltage sensor

PLoS One. 2017 Sep 1;12(9):e0184225. doi: 10.1371/journal.pone.0184225. eCollection 2017.


Visualization of electrical activity in living cells represents an important challenge in context of basic neurophysiological studies. Here we report a new voltage sensitive fluorescent indicator which response could be detected by fluorescence monitoring in a single red channel. To the best of our knowledge, this is the first fluorescent protein-based voltage sensor which uses insertion-into-circular permutant topology to provide an efficient interaction between sensitive and reporter domains. Its fluorescent core originates from red fluorescent protein (FP) FusionRed, which has optimal spectral characteristics to be used in whole body imaging techniques. Indicators using the same domain topology could become a new perspective for the FP-based voltage sensors that are traditionally based on Förster resonance energy transfer (FRET).

MeSH terms

  • Animals
  • Biosensing Techniques / methods
  • Cell Line, Tumor
  • Electrophysiological Phenomena
  • Fluorescence Resonance Energy Transfer / methods*
  • Fluorescent Dyes / metabolism
  • HEK293 Cells
  • Humans
  • Luminescent Proteins / chemistry*
  • Protein Domains
  • Protein Engineering / methods
  • Rats


  • Fluorescent Dyes
  • Luminescent Proteins
  • red fluorescent protein