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Proc Biol Sci
1997 Aug 22;2641385:1157-65. doi: 10.1098/rspb.1997.0160.
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Mechanisms of modulation by internal protons of cyclic nucleotide-gated channels cloned from sensory receptor cells.
Gavazzo P
,
Picco C
,
Menini A
.
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We have examined the modulation by internal protons of cyclic nucleotide-gated (CNG) channels cloned from bovine olfactory receptor cells and retinal rods. CNG channels were studied in excised inside-out membrane patches from Xenopus laevis oocytes previously injected with the mRNA encoding for the subunit 1 of olfactory or rod channels. Channels were activated by cGMP or cAMP, and currents as a function of cyclic nucleotide concentrations were measured as pHi varied between 7.6 and 5.0. Increasing internal proton concentrations caused a partial blockage of the single-channel current, consistent with protonation of a single acidic site with a pK1 of 4.5-4.7, both in rod and in olfactory CNG channels. Channel gating properties were also affected by internal protons. The open probability at low cyclic nucleotide concentrations was greatly increased by lowering pHi, and the increase was larger when channels were activated by cAMP than by cGMP. Therefore, internal protons affected both channel permeation and gating properties, causing a reduction in single-channel current and an increase in open probability. These effects are likely to be caused by different titratable groups on the channel.
Altenhofen,
Control of ligand specificity in cyclic nucleotide-gated channels from rod photoreceptors and olfactory epithelium.
1991, Pubmed,
Xenbase
Altenhofen,
Control of ligand specificity in cyclic nucleotide-gated channels from rod photoreceptors and olfactory epithelium.
1991,
Pubmed
,
Xenbase
Bucossi,
Single-channel properties of ionic channels gated by cyclic nucleotides.
1997,
Pubmed
,
Xenbase
Chen,
A new subunit of the cyclic nucleotide-gated cation channel in retinal rods.
1993,
Pubmed
,
Xenbase
Colclasure,
Cytosolic protein concentration is the primary volume signal for swelling-induced [K-Cl] cotransport in dog red cells.
1992,
Pubmed
Gordon,
Localization of regions affecting an allosteric transition in cyclic nucleotide-activated channels.
1995,
Pubmed
,
Xenbase
Goulding,
Molecular mechanism of cyclic-nucleotide-gated channel activation.
1994,
Pubmed
,
Xenbase
Kaupp,
Family of cyclic nucleotide gated ion channels.
1995,
Pubmed
Kaupp,
Primary structure and functional expression from complementary DNA of the rod photoreceptor cyclic GMP-gated channel.
1989,
Pubmed
,
Xenbase
Ludwig,
Primary structure of cAMP-gated channel from bovine olfactory epithelium.
1990,
Pubmed
Melton,
Efficient in vitro synthesis of biologically active RNA and RNA hybridization probes from plasmids containing a bacteriophage SP6 promoter.
1984,
Pubmed
Menini,
Cyclic nucleotide-gated channels in visual and olfactory transduction.
1995,
Pubmed
Picco,
Modulation by internal protons of native cyclic nucleotide-gated channels from retinal rods.
1996,
Pubmed
Root,
Two identical noninteracting sites in an ion channel revealed by proton transfer.
1994,
Pubmed
,
Xenbase
Scott,
Molecular interactions of 3',5'-cyclic purine analogues with the binding site of retinal rod ion channels.
1995,
Pubmed
Scott,
Predicted ligand interactions of 3'5'-cyclic nucleotide-gated channel binding sites: comparison of retina and olfactory binding site models.
1996,
Pubmed
Sesti,
The multi-ion nature of the cGMP-gated channel from vertebrate rods.
1995,
Pubmed
,
Xenbase
Tanaka,
The effects of protons on 3',5'-cGMP-activated currents in photoreceptor patches.
1993,
Pubmed
Tibbs,
Allosteric activation and tuning of ligand efficacy in cyclic-nucleotide-gated channels.
1997,
Pubmed
,
Xenbase
Torre,
Transduction and adaptation in sensory receptor cells.
1995,
Pubmed
Varnum,
Molecular mechanism for ligand discrimination of cyclic nucleotide-gated channels.
1995,
Pubmed
Zagotta,
Structure and function of cyclic nucleotide-gated channels.
1996,
Pubmed
Zimmerman,
Cyclic nucleotide gated channels.
1995,
Pubmed
