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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.


Effects of intracellular Cd2+ on the C terminus–truncated CLC-0 (CLC0-TM). (A) Current of the eYFP-tagged CLC0-TM activated by a voltage family from 60 to −160 mV in a −20-mV voltage step. Excised inside-out patch recordings. Tail voltage was −100 mV. (B) Effects of intracellular Cd2+ on the current of CLC0-TM monitored by continuously applying a voltage pulse of −100 mV (40 ms) every 2 s. Currents at the end of the −100-mV voltage step are plotted against time. 100 µM Cd2+ was applied as indicated by the horizontal red line. (Inset) Comparison of the recording traces before and after Cd2+ application. Dashed line indicates the zero-current level.
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fig11: Effects of intracellular Cd2+ on the C terminus–truncated CLC-0 (CLC0-TM). (A) Current of the eYFP-tagged CLC0-TM activated by a voltage family from 60 to −160 mV in a −20-mV voltage step. Excised inside-out patch recordings. Tail voltage was −100 mV. (B) Effects of intracellular Cd2+ on the current of CLC0-TM monitored by continuously applying a voltage pulse of −100 mV (40 ms) every 2 s. Currents at the end of the −100-mV voltage step are plotted against time. 100 µM Cd2+ was applied as indicated by the horizontal red line. (Inset) Comparison of the recording traces before and after Cd2+ application. Dashed line indicates the zero-current level.

Mentions: Because C229 and H231 are located near the intracellular end of the transmembrane domain and interactions between the transmembrane domain and the cytoplasmic domain have been demonstrated in CLC molecules (Feng et al., 2010; Bennetts and Parker, 2013), the cytoplasmic domain of CLC-0 may influence Cd2+ inhibition. We thus tested the intracellular Cd2+ effect on a CLC-0 mutant in which the C-terminal region of the channel after residue 530 is replaced with a fluorescent protein. As reported previously (Bykova et al., 2006), this CLC-0 mutant (abbreviated as “CLC0-TM”) generates hyperpolarization-activated currents (Fig. 11 A). Interestingly, Cd2+ did not inhibit but potentiated this mutant (Fig. 11 B), suggesting that the cytoplasmic domain of the CLC channel may also be involved in the intracellular Cd2+ modulation, likely through its interaction with the transmembrane domain.


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

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

Effects of intracellular Cd2+ on the C terminus–truncated CLC-0 (CLC0-TM). (A) Current of the eYFP-tagged CLC0-TM activated by a voltage family from 60 to −160 mV in a −20-mV voltage step. Excised inside-out patch recordings. Tail voltage was −100 mV. (B) Effects of intracellular Cd2+ on the current of CLC0-TM monitored by continuously applying a voltage pulse of −100 mV (40 ms) every 2 s. Currents at the end of the −100-mV voltage step are plotted against time. 100 µM Cd2+ was applied as indicated by the horizontal red line. (Inset) Comparison of the recording traces before and after Cd2+ application. Dashed line indicates the zero-current level.
© Copyright Policy - openaccess
Related In: Results  -  Collection

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

fig11: Effects of intracellular Cd2+ on the C terminus–truncated CLC-0 (CLC0-TM). (A) Current of the eYFP-tagged CLC0-TM activated by a voltage family from 60 to −160 mV in a −20-mV voltage step. Excised inside-out patch recordings. Tail voltage was −100 mV. (B) Effects of intracellular Cd2+ on the current of CLC0-TM monitored by continuously applying a voltage pulse of −100 mV (40 ms) every 2 s. Currents at the end of the −100-mV voltage step are plotted against time. 100 µM Cd2+ was applied as indicated by the horizontal red line. (Inset) Comparison of the recording traces before and after Cd2+ application. Dashed line indicates the zero-current level.
Mentions: Because C229 and H231 are located near the intracellular end of the transmembrane domain and interactions between the transmembrane domain and the cytoplasmic domain have been demonstrated in CLC molecules (Feng et al., 2010; Bennetts and Parker, 2013), the cytoplasmic domain of CLC-0 may influence Cd2+ inhibition. We thus tested the intracellular Cd2+ effect on a CLC-0 mutant in which the C-terminal region of the channel after residue 530 is replaced with a fluorescent protein. As reported previously (Bykova et al., 2006), this CLC-0 mutant (abbreviated as “CLC0-TM”) generates hyperpolarization-activated currents (Fig. 11 A). Interestingly, Cd2+ did not inhibit but potentiated this mutant (Fig. 11 B), suggesting that the cytoplasmic domain of the CLC channel may also be involved in the intracellular Cd2+ modulation, likely through its interaction with the transmembrane domain.

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.