Limits...
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.


Competition between Cd2+ binding and the MTS modification in the I225W/V490W mutant of CLC-0. Current was monitored by a 40-ms test pulse of −100 mV every 2 s. MTS reagents and Cd2+ were applied or washed out at the time points indicated by arrows. (A) Modification of the I225W/V490W mutant with intracellular MTSET (left) or MTSES (right) suppresses the Cd2+ inhibition effect. (B) Cd2+ binding prevents the modification by MTSET (left) or MTSES (right) on the I225W/V490W mutant.
© Copyright Policy - openaccess
Related In: Results  -  Collection

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

fig6: Competition between Cd2+ binding and the MTS modification in the I225W/V490W mutant of CLC-0. Current was monitored by a 40-ms test pulse of −100 mV every 2 s. MTS reagents and Cd2+ were applied or washed out at the time points indicated by arrows. (A) Modification of the I225W/V490W mutant with intracellular MTSET (left) or MTSES (right) suppresses the Cd2+ inhibition effect. (B) Cd2+ binding prevents the modification by MTSET (left) or MTSES (right) on the I225W/V490W mutant.

Mentions: To understand the structural basis of the Cd2+ inhibition, we searched for the amino acid residues involved in forming the Cd2+-binding site. We first tested if cysteine-modifying reagents, such as MTS compounds, could affect Cd2+ inhibition because binding of transition metal ions in proteins frequently involves cysteine (Rulíšek and Vondrásek, 1998). Fig. 6 A shows that the Cd2+ inhibition of the I225W/V490W current, monitored by a 50-ms voltage pulse from 0 to −100 mV every 2 s, was indeed abolished after the patch was treated with intracellularly applied 2-(trimethylammonium)ethyl MTS (MTSET; Fig. 6 A, left) or 2-sulfonatoethyl MTS (MTSES) (Fig. 6 A, right). Consistently, the presence of intracellular Cd2+ reduced the effect of MTSET or MTSES (Fig. 6 B), indicating that at least one cysteine forms part of the binding site, so that Cd2+ binding would protect the cysteine from MTS modifications.


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

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

Competition between Cd2+ binding and the MTS modification in the I225W/V490W mutant of CLC-0. Current was monitored by a 40-ms test pulse of −100 mV every 2 s. MTS reagents and Cd2+ were applied or washed out at the time points indicated by arrows. (A) Modification of the I225W/V490W mutant with intracellular MTSET (left) or MTSES (right) suppresses the Cd2+ inhibition effect. (B) Cd2+ binding prevents the modification by MTSET (left) or MTSES (right) on the I225W/V490W mutant.
© Copyright Policy - openaccess
Related In: Results  -  Collection

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

fig6: Competition between Cd2+ binding and the MTS modification in the I225W/V490W mutant of CLC-0. Current was monitored by a 40-ms test pulse of −100 mV every 2 s. MTS reagents and Cd2+ were applied or washed out at the time points indicated by arrows. (A) Modification of the I225W/V490W mutant with intracellular MTSET (left) or MTSES (right) suppresses the Cd2+ inhibition effect. (B) Cd2+ binding prevents the modification by MTSET (left) or MTSES (right) on the I225W/V490W mutant.
Mentions: To understand the structural basis of the Cd2+ inhibition, we searched for the amino acid residues involved in forming the Cd2+-binding site. We first tested if cysteine-modifying reagents, such as MTS compounds, could affect Cd2+ inhibition because binding of transition metal ions in proteins frequently involves cysteine (Rulíšek and Vondrásek, 1998). Fig. 6 A shows that the Cd2+ inhibition of the I225W/V490W current, monitored by a 50-ms voltage pulse from 0 to −100 mV every 2 s, was indeed abolished after the patch was treated with intracellularly applied 2-(trimethylammonium)ethyl MTS (MTSET; Fig. 6 A, left) or 2-sulfonatoethyl MTS (MTSES) (Fig. 6 A, right). Consistently, the presence of intracellular Cd2+ reduced the effect of MTSET or MTSES (Fig. 6 B), indicating that at least one cysteine forms part of the binding site, so that Cd2+ binding would protect the cysteine from MTS modifications.

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.