Cyclic nucleotide-gated channels belong to the family of voltage-gated ion channels, but pore opening requires the presence of intracellular cyclic nucleotides. In the presence of a saturating agonist, cyclic nucleotide-gated channel gating is voltage independent and it is not known why cyclic nucleotide-gated channels are voltage-insensitive despite harbouring the S4-type voltage sensor. Here we report that, in the presence of Li(+), Na(+) and K(+), the gating of wild-type cyclic nucleotide-gated A1 and native cyclic nucleotide-gated channels is voltage independent, whereas their gating is highly voltage-dependent in the presence of Rb(+), Cs(+) and organic cations. Mutagenesis experiments show that voltage sensing occurs through a voltage sensor composed of charged/polar residues in the pore and of the S4-type voltage sensor. During evolution, cyclic nucleotide-gated channels lose their voltage-sensing ability when Na(+) or K(+) permeate so that the vertebrate photoreceptor cyclic nucleotide-gated channels are open at negative voltages, a necessary condition for phototransduction.

Gating of cyclic nucleotide-gated channels is voltage dependent / Marchesi, Arin; Mazzolini, Monica; Torre, Vincent. - In: NATURE COMMUNICATIONS. - ISSN 2041-1723. - 3:Jul(2012), pp. 973.1-973.12. [10.1038/ncomms1972]

Gating of cyclic nucleotide-gated channels is voltage dependent

Marchesi, Arin;Mazzolini, Monica;Torre, Vincent
2012-01-01

Abstract

Cyclic nucleotide-gated channels belong to the family of voltage-gated ion channels, but pore opening requires the presence of intracellular cyclic nucleotides. In the presence of a saturating agonist, cyclic nucleotide-gated channel gating is voltage independent and it is not known why cyclic nucleotide-gated channels are voltage-insensitive despite harbouring the S4-type voltage sensor. Here we report that, in the presence of Li(+), Na(+) and K(+), the gating of wild-type cyclic nucleotide-gated A1 and native cyclic nucleotide-gated channels is voltage independent, whereas their gating is highly voltage-dependent in the presence of Rb(+), Cs(+) and organic cations. Mutagenesis experiments show that voltage sensing occurs through a voltage sensor composed of charged/polar residues in the pore and of the S4-type voltage sensor. During evolution, cyclic nucleotide-gated channels lose their voltage-sensing ability when Na(+) or K(+) permeate so that the vertebrate photoreceptor cyclic nucleotide-gated channels are open at negative voltages, a necessary condition for phototransduction.
2012
3
Jul
1
12
973
10.1038/ncomms1972
https://www.ncbi.nlm.nih.gov/pubmed/22828633
Marchesi, Arin; Mazzolini, Monica; Torre, Vincent
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11767/15018
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