Platymonas subcordiformis Channelrhodopsin-2 (PsChR2) Function: II. RELATIONSHIP OF THE PHOTOCHEMICAL REACTION CYCLE TO CHANNEL CURRENTS.

The Journal of Biological Chemistry
Istvan SzundiDavid S Kliger

Abstract

Channelrhodopsins, such as the algal phototaxis receptor Platymonas subcordiformis channelrhodopsin-2 (PsChR2), are light-gated cation channels used as optogenetic tools for photocontrol of membrane potential in living cells. Channelrhodopsin (ChR)-mediated photocurrent responses are complex and poorly understood, exhibiting alterations in peak current amplitude, extents and kinetics of inactivation, and kinetics of the recovery of the prestimulus dark current that are sensitive to duration and frequency of photostimuli. From the analysis of time-resolved optical absorption data, presented in the accompanying article, we derived a two-cycle model that describes the photocycles of PsChR2. Here, we applied the model to evaluate the transient currents produced by PsChR2 expressed in HEK293 cells under both fast laser excitation and step-like continuous illumination. Interpretation of the photocurrents in terms of the photocycle kinetics indicates that the O states in both cycles are responsible for the channel current and fit the current transients under the different illumination regimes. The peak and plateau currents in response to a single light step, a train of light pulses, and a light step superimposed on a continuous light ...Continue Reading

References

Oct 14, 2000·Annual Review of Cell and Developmental Biology·J L SpudichE N Spudich
Jun 13, 2002·Proceedings of the National Academy of Sciences of the United States of America·Oleg A SineshchekovJ L Spudich
Jun 29, 2002·Science·Georg NagelPeter Hegemann
Nov 15, 2003·Proceedings of the National Academy of Sciences of the United States of America·Georg NagelErnst Bamberg
Aug 24, 2005·Nature Neuroscience·E BoydenKarl Deisseroth
Sep 20, 2005·Biophysical Journal·Peter HegemannDietrich Gradmann
Nov 27, 2007·Journal of Molecular Biology·Christian BamannErnst Bamberg
Jan 24, 2009·Photochemistry and Photobiology·Konstantin NikolicPatrick Degenaar
Mar 30, 2010·Chemphyschem : a European Journal of Chemical Physics and Physical Chemistry·Katja Stehfest, Peter Hegemann
Aug 24, 2010·Chemphyschem : a European Journal of Chemical Physics and Physical Chemistry·Mirka-Kristin VerhoefenJosef Wachtveitl
Dec 31, 2010·Nature Methods·Karl Deisseroth
Nov 3, 2011·Photochemistry and Photobiology·Sing-Yi HouJ L Spudich
Feb 22, 2012·Progress in Brain Research·Brian Y ChowE Boyden
Feb 27, 2013·The Journal of Biological Chemistry·Eglof RitterFranz J Bartl
Feb 28, 2013·Biophysical Journal·Oleg A SineshchekovJ L Spudich
Mar 20, 2013·Proceedings of the National Academy of Sciences of the United States of America·Víctor A Lórenz-FonfríaJoachim Heberle
Sep 3, 2013·The Journal of Biological Chemistry·Elena G GovorunovaJ L Spudich
Nov 12, 2013·Biochimica Et Biophysica Acta·Víctor A Lórenz-Fonfría, Joachim Heberle
Dec 25, 2013·Chemical Reviews·Oliver P ErnstHideki Kandori
May 15, 2015·The Journal of Biological Chemistry·Istvan SzundiDavid S Kliger

Citations

Oct 16, 2015·Proceedings of the National Academy of Sciences of the United States of America·Víctor A Lórenz-FonfríaJoachim Heberle
Mar 30, 2017·Biophysical Journal·Benjamin S KrausePeter Hegemann

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