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Sci Rep
2016 Jan 22;6:20974. doi: 10.1038/srep20974.
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Quantifying the cooperative subunit action in a multimeric membrane receptor.
Wongsamitkul N
,
Nache V
,
Eick T
,
Hummert S
,
Schulz E
,
Schmauder R
,
Schirmeyer J
,
Zimmer T
,
Benndorf K
.
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In multimeric membrane receptors the cooperative action of the subunits prevents exact knowledge about the operation and the interaction of the individual subunits. We propose a method that permits quantification of ligand binding to and activation effects of the individual binding sites in a multimeric membrane receptor. The power of this method is demonstrated by gaining detailed insight into the subunit action in olfactory cyclic nucleotide-gated CNGA2 ion channels.
Figure 1. Concentration-activation relationships of CNGA2 concatamers.(a) Effect of an increasing number of mut-subunits. The channels are either formed by four monomers (4×wt, 4×mut) or by tetrameric concatamers (wt-wt-wt-wt, mut-wt-wt-wt, mut-mut-wt-wt, mut-mut-mut-wt, mut-mut-mut-mut). All fit parameters are provided by Supplementary Table 1a. (b) Concatamers assemble as tetrameric channels. Expression of either wt-wt-wt-wt or mut-mut-mut-mut channels alone or together with a cRNA ratio 1:1 (N = 14–21). All fit parameters are provided by Supplementary Table 1b. (c) The position of wt-subunits is irrelevant for the concatamer function. The concentration-activation relationships of four concatamers with two wt-subunits and four concatamers with one wt-subunit are plotted. The fit parameters are given in Supplementary Table 1c. The relationships for the concatamers with one wt-subunit were indistinguishable as were the relationships for the concatamers with two wt-subunits (multidimensional t-test with Holm correction, p-value = 1).
Figure 2. Global fit of concentration-activation relationships from five CNGA2 concatamers.(a) Markovian submodels describing the activation gating of five concatamers. The closed-open isomerizations, including their equilibrium constants, E0….E4, are indicated only once at the bottom. They are the same for each equally liganded state. KA1H, KA2H, KA3H, KA4H, KA1L, KA2L, KA3L, and KA4L are the equilibrium association constants for the four high and low affinity binding sites, respectively. E0 and E4 were set to 1.7 × 10−5 and 9.9 × 101 according to the single-channel experiments. (b) Global fit of the data points of the five concatamers shown in a. The values of the equilibrium constants are provided by Table 1. (c) Occupancy of the states (P) predicted by the 1wt-submodel as function of the [cGMP].
Biskup,
Relating ligand binding to activation gating in CNGA2 channels.
2007, Pubmed,
Xenbase
Biskup,
Relating ligand binding to activation gating in CNGA2 channels.
2007,
Pubmed
,
Xenbase
Bönigk,
The native rat olfactory cyclic nucleotide-gated channel is composed of three distinct subunits.
1999,
Pubmed
Carter,
The use of double mutants to detect structural changes in the active site of the tyrosyl-tRNA synthetase (Bacillus stearothermophilus).
1984,
Pubmed
Dhallan,
Primary structure and functional expression of a cyclic nucleotide-activated channel from olfactory neurons.
1990,
Pubmed
Goulding,
Molecular mechanism of cyclic-nucleotide-gated channel activation.
1994,
Pubmed
,
Xenbase
Hamill,
Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches.
1981,
Pubmed
Hidalgo,
Revealing the architecture of a K+ channel pore through mutant cycles with a peptide inhibitor.
1995,
Pubmed
,
Xenbase
Hlavackova,
Sequential inter- and intrasubunit rearrangements during activation of dimeric metabotropic glutamate receptor 1.
2012,
Pubmed
Kaupp,
Molecular diversity of pacemaker ion channels.
2001,
Pubmed
Kaupp,
Cyclic nucleotide-gated ion channels.
2002,
Pubmed
Kusch,
Role of the S4-S5 linker in CNG channel activation.
2010,
Pubmed
Lape,
On the nature of partial agonism in the nicotinic receptor superfamily.
2008,
Pubmed
Matulef,
Cyclic nucleotide-gated ion channels.
2003,
Pubmed
Nache,
Hysteresis of ligand binding in CNGA2 ion channels.
2013,
Pubmed
,
Xenbase
Nache,
Activation of olfactory-type cyclic nucleotide-gated channels is highly cooperative.
2005,
Pubmed
,
Xenbase
Nache,
Differential regulation by cyclic nucleotides of the CNGA4 and CNGB1b subunits in olfactory cyclic nucleotide-gated channels.
2012,
Pubmed
Sautter,
An isoform of the rod photoreceptor cyclic nucleotide-gated channel beta subunit expressed in olfactory neurons.
1998,
Pubmed
Song,
Testing for microscopic reversibility in the gating of maxi K+ channels using two-dimensional dwell-time distributions.
1994,
Pubmed
Tibbs,
A state-independent interaction between ligand and a conserved arginine residue in cyclic nucleotide-gated channels reveals a functional polarity of the cyclic nucleotide binding site.
1998,
Pubmed
,
Xenbase
Whitty,
Cooperativity and biological complexity.
2008,
Pubmed
Wongsamitkul,
Corrigendum: Quantifying the cooperative subunit action in a multimeric membrane receptor.
2018,
Pubmed
Zagotta,
Structure and function of cyclic nucleotide-gated channels.
1996,
Pubmed
