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Modulation of the slow/common gating of CLC channels by intracellular cadmium.

Yu Y, Tsai MF, Yu WP, Chen TY - J. Gen. Physiol. (2015)

Bottom Line: Here, we found that intracellularly applied Cd(2+) reduces the current of CLC-0 because of its inhibition on the slow gating.Our experimental results suggest that mutations of the corresponding residues in CLC-0 change the subunit interaction and alter the slow gating of CLC-0.The effect of these mutations on modulations of slow gating of CLC channels by intracellular Cd(2+) likely depends on their alteration of subunit interactions.

View Article: PubMed Central - HTML - PubMed

Affiliation: Center for Neuroscience and Department of Neurology, University of California, Davis, Davis, CA 95618 Center for Neuroscience and Department of Neurology, University of California, Davis, Davis, CA 95618.

No MeSH data available.


Crystal structure of CLC-ec1 as a guiding roadmap for examining the transmembrane domains of CLC-0 and CLC-1. The residues R205 (yellow) and Q207 (green) of CLC-ec1 correspond to C229 and H231 of CLC-0, or S294 and Y296 of CLC-1, respectively. Residues I201 (blue) and I422 (purple) are also depicted, which correspond to I225 and V490 of CLC-0, or I290 and I556 of CLC-1, respectively. The double mutations I201W/I422W in CLC-ec1 disrupted the dimeric interaction in this E. coli CLC and generated functional monomeric CLC-ec1 proteins (Robertson et al., 2010).
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fig1: Crystal structure of CLC-ec1 as a guiding roadmap for examining the transmembrane domains of CLC-0 and CLC-1. The residues R205 (yellow) and Q207 (green) of CLC-ec1 correspond to C229 and H231 of CLC-0, or S294 and Y296 of CLC-1, respectively. Residues I201 (blue) and I422 (purple) are also depicted, which correspond to I225 and V490 of CLC-0, or I290 and I556 of CLC-1, respectively. The double mutations I201W/I422W in CLC-ec1 disrupted the dimeric interaction in this E. coli CLC and generated functional monomeric CLC-ec1 proteins (Robertson et al., 2010).

Mentions: It has been suggested that interactions between the two CLC subunits are involved in the slow/common gating processes (Estévez and Jentsch, 2002; Bykova et al., 2006). Crystal structures of the Escherichia coli CLC (CLC-ec1) and a eukaryotic CLC transporter CmCLC show extensive helix packing in the subunit interface (Dutzler et al., 2002; Feng et al., 2010; Robertson et al., 2010). At this flat, nonpolar interface, hydrophobic residues such as valine, leucine, and isoleucine form most of the cross-subunit contacts (Dutzler et al., 2002; Robertson et al., 2010). Replacing two isoleucine residues, I201 and I422, at the dimer interface of CLC-ec1 (see Fig. 1 for the locations of these two residues) with tryptophan disrupts the dimeric architecture, and the I201W/I422W double mutant of CLC-ec1 exists as a monomer (Robertson et al., 2010). Coincidentally, previous work has also demonstrated that mutations of I290 and I556 of CLC-1 (which correspond to I201 and I422, respectively, in CLC-ec1) alter the common gating (Pusch et al., 1995; Kubisch et al., 1998; Saviane et al., 1999). Collectively, these results suggest that molecular events occurring in the CLC dimer interface contribute to slow/common gating.


Modulation of the slow/common gating of CLC channels by intracellular cadmium.

Yu Y, Tsai MF, Yu WP, Chen TY - J. Gen. Physiol. (2015)

Crystal structure of CLC-ec1 as a guiding roadmap for examining the transmembrane domains of CLC-0 and CLC-1. The residues R205 (yellow) and Q207 (green) of CLC-ec1 correspond to C229 and H231 of CLC-0, or S294 and Y296 of CLC-1, respectively. Residues I201 (blue) and I422 (purple) are also depicted, which correspond to I225 and V490 of CLC-0, or I290 and I556 of CLC-1, respectively. The double mutations I201W/I422W in CLC-ec1 disrupted the dimeric interaction in this E. coli CLC and generated functional monomeric CLC-ec1 proteins (Robertson et al., 2010).
© Copyright Policy - openaccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4664824&req=5

fig1: Crystal structure of CLC-ec1 as a guiding roadmap for examining the transmembrane domains of CLC-0 and CLC-1. The residues R205 (yellow) and Q207 (green) of CLC-ec1 correspond to C229 and H231 of CLC-0, or S294 and Y296 of CLC-1, respectively. Residues I201 (blue) and I422 (purple) are also depicted, which correspond to I225 and V490 of CLC-0, or I290 and I556 of CLC-1, respectively. The double mutations I201W/I422W in CLC-ec1 disrupted the dimeric interaction in this E. coli CLC and generated functional monomeric CLC-ec1 proteins (Robertson et al., 2010).
Mentions: It has been suggested that interactions between the two CLC subunits are involved in the slow/common gating processes (Estévez and Jentsch, 2002; Bykova et al., 2006). Crystal structures of the Escherichia coli CLC (CLC-ec1) and a eukaryotic CLC transporter CmCLC show extensive helix packing in the subunit interface (Dutzler et al., 2002; Feng et al., 2010; Robertson et al., 2010). At this flat, nonpolar interface, hydrophobic residues such as valine, leucine, and isoleucine form most of the cross-subunit contacts (Dutzler et al., 2002; Robertson et al., 2010). Replacing two isoleucine residues, I201 and I422, at the dimer interface of CLC-ec1 (see Fig. 1 for the locations of these two residues) with tryptophan disrupts the dimeric architecture, and the I201W/I422W double mutant of CLC-ec1 exists as a monomer (Robertson et al., 2010). Coincidentally, previous work has also demonstrated that mutations of I290 and I556 of CLC-1 (which correspond to I201 and I422, respectively, in CLC-ec1) alter the common gating (Pusch et al., 1995; Kubisch et al., 1998; Saviane et al., 1999). Collectively, these results suggest that molecular events occurring in the CLC dimer interface contribute to slow/common gating.

Bottom Line: Here, we found that intracellularly applied Cd(2+) reduces the current of CLC-0 because of its inhibition on the slow gating.Our experimental results suggest that mutations of the corresponding residues in CLC-0 change the subunit interaction and alter the slow gating of CLC-0.The effect of these mutations on modulations of slow gating of CLC channels by intracellular Cd(2+) likely depends on their alteration of subunit interactions.

View Article: PubMed Central - HTML - PubMed

Affiliation: Center for Neuroscience and Department of Neurology, University of California, Davis, Davis, CA 95618 Center for Neuroscience and Department of Neurology, University of California, Davis, Davis, CA 95618.

No MeSH data available.