1. MerMAIDs: a family of metagenomically discovered marine anion-conducting and intensely desensitizing channelrhodopsins
- Author
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Jonas Wietek, Anke Keidel, Franz Bartl, Meike Luck, Peter Hildebrandt, Arita Silapetere, Paul Fischer, Johannes Vierock, Peter Hegemann, Johannes Oppermann, J. Simon Wiegert, Matthias Broser, Bernhard Liepe, Enrico Peter, Joel C.D. Kaufmann, Silvia Rodriguez-Rozada, Oded Béjà, and José Flores-Uribe
- Subjects
Anions ,0301 basic medicine ,Ion permeation ,Light ,Science ,Biophysics ,General Physics and Astronomy ,Channelrhodopsin ,02 engineering and technology ,Optogenetics ,Article ,General Biochemistry, Genetics and Molecular Biology ,Viral Proteins ,03 medical and health sciences ,Bacterial Proteins ,Channelrhodopsins ,Animals ,Humans ,Seawater ,14. Life underwater ,lcsh:Science ,Phylogeny ,Ion channel ,Neurons ,Multidisciplinary ,Bacteria ,Chemistry ,fungi ,General Chemistry ,021001 nanoscience & nanotechnology ,Kinetics ,030104 developmental biology ,Multigene Family ,Viruses ,Rapid desensitization ,Metagenome ,Permeation and transport ,lcsh:Q ,0210 nano-technology ,Neuroscience - Abstract
Channelrhodopsins (ChRs) are algal light-gated ion channels widely used as optogenetic tools for manipulating neuronal activity. ChRs desensitize under continuous bright-light illumination, resulting in a significant decline of photocurrents. Here we describe a metagenomically identified family of phylogenetically distinct anion-conducting ChRs (designated MerMAIDs). MerMAIDs almost completely desensitize during continuous illumination due to accumulation of a late non-conducting photointermediate that disrupts the ion permeation pathway. MerMAID desensitization can be fully explained by a single photocycle in which a long-lived desensitized state follows the short-lived conducting state. A conserved cysteine is the critical factor in desensitization, as its mutation results in recovery of large stationary photocurrents. The rapid desensitization of MerMAIDs enables their use as optogenetic silencers for transient suppression of individual action potentials without affecting subsequent spiking during continuous illumination. Our results could facilitate the development of optogenetic tools from metagenomic databases and enhance general understanding of ChR function., Channelrhodopsins (ChRs) are algal light-gated ion channels used as optogenetic tools for manipulating neuronal activity. Here authors present a metagenomically identified family of phylogenetically distinct anion-conducting ChRs (MerMAIDs) which desensitize during continuous illumination due to accumulation of a non-conducting photointermediate.
- Published
- 2019