A single point mutation converts a proton-pumping rhodopsin into a red-shifted, turn-on fluorescent sensor for chloride
Jasmine N. Tutol, Jessica Lee, Hsichuan Chi, Farah Faizuddin, Sameera Abeyrathna, Qin Zhou, Faruck Morcos, Gabriele Meloni, Sheel C. Dodani
Abstract
, expressing a GR1 fusion with a cyan fluorescent protein, show that GR1 does not pump ions nor sense membrane potential but instead provides a reversible, ratiometric readout of changes in extracellular chloride at the membrane. This discovery sets the stage to use natural and laboratory-guided evolution to build a family of rhodopsin-based fluorescent chloride sensors with improved properties for cellular applications and learn how proteins can evolve and adapt to bind anions in water.
Topics & Concepts
FluorescenceRhodopsinTurn (biochemistry)ProtonChlorideChemistryPhotochemistrySingle pointBiophysicsOpticsPhysicsBiologyBiochemistryOrganic chemistryRetinalMechanicsComputer simulationQuantum mechanicsPhotoreceptor and optogenetics researchNeuroscience and Neuropharmacology ResearchPhotochromic and Fluorescence Chemistry