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Characterization of Engineered Channelrhodopsin Variants with Improved Properties and Kinetics


Lin, J and Lin, MZ and Steinbach, P and Tsien, RY, Characterization of Engineered Channelrhodopsin Variants with Improved Properties and Kinetics, Biophysical Journal, 96 pp. 1803-1814. ISSN 0006-3495 (2009) [Refereed Article]

Copyright Statement

Copyright 2009 by the Biophysical Society

DOI: doi:10.1016/j.bpj.2008.11.034


Channelrhodopsin 2 (ChR2), a light-activated nonselective cationic channel from Chlamydomonas reinhardtii, has become a useful tool to excite neurons into which it is transfected. The other ChR from Chlamydomonas, ChR1, has attracted less attention because of its proton-selective permeability. By making chimeras of the transmembrane domains of ChR1 and ChR2, combined with site-directed mutagenesis, we developed a ChR variant, named ChEF, that exhibits significantly less inactivation during persistent light stimulation. ChEF undergoes only 33% inactivation, compared with 77% for ChR2. Point mutation of Ile170 of ChEF to Val (yielding "ChIEF") accelerates the rate of channel closure while retaining reduced inactivation, leading to more consistent responses when stimulated above 25 Hz in both HEK293 cells and cultured hippocampal neurons. In addition, these variants have altered spectral responses, light sensitivity, and channel selectivity. ChEF and ChIEF allow more precise temporal control of depolarization, and can induce action potential trains that more closely resemble natural spiking patterns.

Item Details

Item Type:Refereed Article
Keywords:Optogenetics, neuroscience
Research Division:Biomedical and Clinical Sciences
Research Group:Neurosciences
Research Field:Neurosciences not elsewhere classified
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the biological sciences
UTAS Author:Lin, J (Dr John Lin)
ID Code:97389
Year Published:2009
Web of Science® Times Cited:467
Deposited By:Medicine
Deposited On:2014-12-15
Last Modified:2015-03-12

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