Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
J Physiol
2004 Nov 01;560Pt 3:605-16. doi: 10.1113/jphysiol.2004.070193.
Show Gene links
Show Anatomy links
Effects of permeating ions and cGMP on gating and conductance of rod-type cyclic nucleotide-gated (CNGA1) channels.
Kusch J
,
Nache V
,
Benndorf K
.
???displayArticle.abstract???
Cyclic nucleotide-gated (CNG) channels are tetrameric non-specific cation channels. They mediate the receptor potentials in photoreceptors and cells of the olfactory epithelium and they are activated by the binding of cyclic nucleotides such as cGMP and cAMP. Previous studies in homotetrameric CNGA1 channels, activated with covalently bound cGMP, presented evidence that partially liganded channels cause partial channel opening (Ruiz & Karpen, 1997, 1999). Here, homotetrameric CNGA1 channels were expressed in Xenopus oocytes. Conductance and gating of these channels were studied as a function of the concentration of freely diffusible cGMP and with different permeating ions. At saturating cGMP the current levels distributed around a single mean in a Gaussian fashion and the open times were long. At low cGMP, however, the current levels were heterogeneous: they were smaller than those at saturating cGMP, equal, or larger. The open times were short. Ions generating the larger single-channel currents (Na(+) > K(+) > Rb(+)) concomitantly increased the heterogeneity of current levels and decreased the open probability and open times. The results suggest that the activation of CNGA1 channels by cGMP and ions staying longer in the pore is associated with less extensive and less frequent conformational fluctuations of the channel pore.
Becchetti,
Cyclic nucleotide-gated channels. Pore topology studied through the accessibility of reporter cysteines.
1999, Pubmed,
Xenbase
Becchetti,
Cyclic nucleotide-gated channels. Pore topology studied through the accessibility of reporter cysteines.
1999,
Pubmed
,
Xenbase
Benndorf,
Gating by cyclic GMP and voltage in the alpha subunit of the cyclic GMP-gated channel from rod photoreceptors.
1999,
Pubmed
,
Xenbase
Bönigk,
The native rat olfactory cyclic nucleotide-gated channel is composed of three distinct subunits.
1999,
Pubmed
Bradley,
Nomenclature for ion channel subunits.
2001,
Pubmed
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
Doyle,
The structure of the potassium channel: molecular basis of K+ conduction and selectivity.
1998,
Pubmed
Finn,
Cyclic nucleotide-gated ion channels: an extended family with diverse functions.
1996,
Pubmed
Flynn,
Conformational changes in S6 coupled to the opening of cyclic nucleotide-gated channels.
2001,
Pubmed
,
Xenbase
Frings,
Profoundly different calcium permeation and blockage determine the specific function of distinct cyclic nucleotide-gated channels.
1995,
Pubmed
,
Xenbase
Gamel,
The interaction of Na(+) and K(+) in the pore of cyclic nucleotide-gated channels.
2000,
Pubmed
,
Xenbase
Gordon,
Localization of regions affecting an allosteric transition in cyclic nucleotide-activated channels.
1995,
Pubmed
,
Xenbase
Hanke,
cGMP-dependent channel protein from photoreceptor membranes: single-channel activity of the purified and reconstituted protein.
1988,
Pubmed
Holmgren,
Influence of permeant ions on gating in cyclic nucleotide-gated channels.
2003,
Pubmed
Ildefonse,
Single-channel study of the cGMP-dependent conductance of retinal rods from incorporation of native vesicles into planar lipid bilayers.
1991,
Pubmed
Kaupp,
Cyclic nucleotide-gated ion channels.
2002,
Pubmed
Kaupp,
Primary structure and functional expression from complementary DNA of the rod photoreceptor cyclic GMP-gated channel.
1989,
Pubmed
,
Xenbase
Körschen,
A 240 kDa protein represents the complete beta subunit of the cyclic nucleotide-gated channel from rod photoreceptor.
1995,
Pubmed
Liu,
Change of pore helix conformational state upon opening of cyclic nucleotide-gated channels.
2000,
Pubmed
,
Xenbase
Möttig,
Molecular regions controlling the activity of CNG channels.
2001,
Pubmed
,
Xenbase
Nizzari,
Single-channel properties of cloned cGMP-activated channels from retinal rods.
1993,
Pubmed
,
Xenbase
Root,
Two identical noninteracting sites in an ion channel revealed by proton transfer.
1994,
Pubmed
,
Xenbase
Ruiz,
Single cyclic nucleotide-gated channels locked in different ligand-bound states.
1997,
Pubmed
,
Xenbase
Ruiz,
Opening mechanism of a cyclic nucleotide-gated channel based on analysis of single channels locked in each liganded state.
1999,
Pubmed
,
Xenbase
Sigworth,
Open channel noise. I. Noise in acetylcholine receptor currents suggests conformational fluctuations.
1985,
Pubmed
Sun,
Exposure of residues in the cyclic nucleotide-gated channel pore: P region structure and function in gating.
1996,
Pubmed
Swenson,
K+ channels close more slowly in the presence of external K+ and Rb+.
1981,
Pubmed
Taylor,
Conductance and kinetics of single cGMP-activated channels in salamander rod outer segments.
1995,
Pubmed
Tränkner,
Molecular basis of an inherited form of incomplete achromatopsia.
2004,
Pubmed
Weitz,
Subunit stoichiometry of the CNG channel of rod photoreceptors.
2002,
Pubmed
Zheng,
Gating rearrangements in cyclic nucleotide-gated channels revealed by patch-clamp fluorometry.
2000,
Pubmed
Zhong,
The heteromeric cyclic nucleotide-gated channel adopts a 3A:1B stoichiometry.
2002,
Pubmed
Zimmerman,
Cyclic nucleotide gated channels.
1995,
Pubmed
