Format

Send to

Choose Destination
J Biol Chem. 2012 Feb 10;287(7):4818-25. doi: 10.1074/jbc.M111.326207. Epub 2011 Dec 2.

Bioinformatic and mutational analysis of channelrhodopsin-2 protein cation-conducting pathway.

Author information

1
Department of Biomedical Sciences, University of Padova, viale Colombo 3, 35100 Padova, Italy.

Abstract

Channelrhodopsin-2 (ChR2) is a light-gated cation channel widely used as a biotechnological tool to control membrane depolarization in various cell types and tissues. Although several ChR2 variants with modified properties have been generated, the structural determinants of the protein function are largely unresolved. We used bioinformatic modeling of the ChR2 structure to identify the putative cationic pathway within the channel, which is formed by a system of inner cavities that are uniquely present in this microbial rhodopsin. Site-directed mutagenesis combined with patch clamp analysis in HeLa cells was used to determine key residues involved in ChR2 conductance and selectivity. Among them, Gln-56 is important for ion conductance, whereas Ser-63, Thr-250, and Asn-258 are previously unrecognized residues involved in ion selectivity and photocurrent kinetics. This study widens the current structural information on ChR2 and can assist in the design of new improved variants for specific biological applications.

PMID:
22139833
PMCID:
PMC3281600
DOI:
10.1074/jbc.M111.326207
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center