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Biophys J
2006 May 01;909:3146-54. doi: 10.1529/biophysj.105.078667.
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Gating of cyclic nucleotide-gated (CNGA1) channels by cGMP jumps and depolarizing voltage steps.
Nache V, Kusch J, Hagen V, Benndorf K.
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We expressed rod-type homotetrameric cyclic nucleotide-gated (CNGA1) channels in Xenopus oocytes and studied activation by photolysis-induced jumps of the 3',5'-cyclic guanosine monophosphate (cGMP) concentration and by voltage steps. cGMP jumps to increasing concentrations up to the EC50 value of 46.5 microM decelerate the activation gating, indicative that even at concentrations of cGMP < EC50 binding is not rate limiting. Above the EC50 value, activation by cGMP jumps is again accelerated to the higher concentrations. At the same cGMP concentration, the speed of the activation gating by depolarizing voltage steps is roughly similar to that by cGMP jumps. Permeating ions passing the pore more slowly (Rb+ > K+ > Na+) slow down the activation time course. At the single-channel level, cGMP jumps to high concentrations cause openings directly to the main open level without passing sublevels. From these results it is concluded that at both low and high cGMP the gating of homotetrameric CNGA1 channels is not rate-limited by the cGMP binding but by conformational changes of the channel which are voltage dependent and include movements in the pore region.
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 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 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 Franke,
Liquid filament switch for ultra-fast exchanges of solutions at excised patches of synaptic membrane of crayfish muscle.
1987,
Pubmed Gamel,
The interaction of Na(+) and K(+) in the pore of cyclic nucleotide-gated channels.
2000,
Pubmed
,
Xenbase Goulding,
Molecular mechanism of cyclic-nucleotide-gated channel activation.
1994,
Pubmed
,
Xenbase Hagen,
Coumarinylmethyl esters for ultrafast release of high concentrations of cyclic nucleotides upon one- and two-photon photolysis.
2005,
Pubmed
,
Xenbase Hagen,
Highly Efficient and Ultrafast Phototriggers for cAMP and cGMP by Using Long-Wavelength UV/Vis-Activation This work was supported by the Deutsche Forschungsgemeinschaft, the European Union, and the Fonds der Chemischen Industrie. We thank B. Dekowski and J. Loßmann for technical assistance and S. Hecht for proof reading.
2001,
Pubmed Holmgren,
Influence of permeant ions on gating in cyclic nucleotide-gated channels.
2003,
Pubmed Karpen,
Gating kinetics of the cyclic-GMP-activated channel of retinal rods: flash photolysis and voltage-jump studies.
1988,
Pubmed Kaupp,
Primary structure and functional expression from complementary DNA of the rod photoreceptor cyclic GMP-gated channel.
1989,
Pubmed
,
Xenbase Kaupp,
Cyclic nucleotide-gated ion channels.
2002,
Pubmed Körschen,
A 240 kDa protein represents the complete beta subunit of the cyclic nucleotide-gated channel from rod photoreceptor.
1995,
Pubmed Kusch,
Effects of permeating ions and cGMP on gating and conductance of rod-type cyclic nucleotide-gated (CNGA1) channels.
2004,
Pubmed
,
Xenbase Li,
Cyclic nucleotide-gated channels: structural basis of ligand efficacy and allosteric modulation.
1997,
Pubmed Liu,
Change of pore helix conformational state upon opening of cyclic nucleotide-gated channels.
2000,
Pubmed
,
Xenbase Markwardt,
Gating of maxi K+ channels studied by Ca2+ concentration jumps in excised inside-out multi-channel patches (myocytes from guinea pig urinary bladder).
1992,
Pubmed Matulef,
Molecular rearrangements in the ligand-binding domain of cyclic nucleotide-gated channels.
1999,
Pubmed
,
Xenbase Nache,
Activation of olfactory-type cyclic nucleotide-gated channels is highly cooperative.
2005,
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 Ruiz,
Single cyclic nucleotide-gated channels locked in different ligand-bound states.
1997,
Pubmed
,
Xenbase Sun,
Exposure of residues in the cyclic nucleotide-gated channel pore: P region structure and function in gating.
1996,
Pubmed Taylor,
Conductance and kinetics of single cGMP-activated channels in salamander rod outer segments.
1995,
Pubmed Tibbs,
Allosteric activation and tuning of ligand efficacy in cyclic-nucleotide-gated channels.
1997,
Pubmed
,
Xenbase Tränkner,
Molecular basis of an inherited form of incomplete achromatopsia.
2004,
Pubmed Weitz,
Subunit stoichiometry of the CNG channel of rod photoreceptors.
2002,
Pubmed Zagotta,
Structure and function of cyclic nucleotide-gated channels.
1996,
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 Zufall,
Rapid application and removal of second messengers to cyclic nucleotide-gated channels from olfactory epithelium.
1993,
Pubmed
