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 Biol Chem
2018 Feb 23;2938:2903-2914. doi: 10.1074/jbc.M117.810432.
Show Gene links
Show Anatomy links
A triad of residues is functionally transferrable between 5-HT3 serotonin receptors and nicotinic acetylcholine receptors.
Mosesso R
,
Dougherty DA
.
???displayArticle.abstract???
Cys-loop receptors are pentameric ligand-gated ion channels that facilitate communication within the nervous system. Upon neurotransmitter binding, these receptors undergo an allosteric activation mechanism connecting the binding event to the membrane-spanning channel pore, which expands to conduct ions. Some of the earliest steps in this activation mechanism are carried out by residues proximal to the binding site, the relative positioning of which may reflect functional differences among members of the Cys-loop family of receptors. Herein, we investigated key side-chain interactions near the binding site via mutagenesis and two-electrode voltage-clamp electrophysiology in serotonin-gated 5-HT3A receptors (5-HT3ARs) and nicotinic acetylcholine receptors (nAChRs) expressed in Xenopus laevis oocytes. We found that a triad of residues aligning to Thr-152, Glu-209, and Lys-211 in the 5-HT3AR can be exchanged between the homomeric 5-HT3AR and the muscle-type nAChR α-subunit with small functional consequences. Via triple mutant cycle analysis, we demonstrated that this triad forms an interdependent network in the muscle-type nAChR. Furthermore, nAChR-type mutations of the 5-HT3AR affect the affinity of nicotine, a competitive antagonist of 5-HT3ARs, in a cooperative manner. Using mutant cycle analyses between the 5-HT3A triad, loop A residues Asn-101 and Glu-102, β9 residue Lys-197, and the channel gate at Thr-257, we observed that residues in this region are energetically linked to the channel gate and are particularly sensitive to mutations that introduce a net positive charge. This study expands our understanding of the differences and similarities in the activation mechanisms of Cys-loop receptors.
Albuquerque,
Mammalian nicotinic acetylcholine receptors: from structure to function.
2009, Pubmed
Albuquerque,
Mammalian nicotinic acetylcholine receptors: from structure to function.
2009,
Pubmed
Betz,
Glycine receptors: recent insights into their structural organization and functional diversity.
2006,
Pubmed
Celie,
Nicotine and carbamylcholine binding to nicotinic acetylcholine receptors as studied in AChBP crystal structures.
2004,
Pubmed
Colquhoun,
Why the Schild method is better than Schild realised.
2007,
Pubmed
Cross,
Enhancement by 5-hydroxytryptamine and analogues of desensitization of neuronal and muscle nicotinic receptors expressed in Xenopus oocytes.
1995,
Pubmed
,
Xenbase
Dellisanti,
Crystal structure of the extracellular domain of nAChR alpha1 bound to alpha-bungarotoxin at 1.94 A resolution.
2007,
Pubmed
Dougherty,
The cation-π interaction.
2013,
Pubmed
Dougherty,
In vivo incorporation of non-canonical amino acids by using the chemical aminoacylation strategy: a broadly applicable mechanistic tool.
2014,
Pubmed
,
Xenbase
Giastas,
Understanding structure-function relationships of the human neuronal acetylcholine receptor: insights from the first crystal structures of neuronal subunits.
2018,
Pubmed
Gleitsman,
Long-range coupling in an allosteric receptor revealed by mutant cycle analysis.
2009,
Pubmed
,
Xenbase
Gurley,
Nicotinic agonists competitively antagonize serotonin at mouse 5-HT3 receptors expressed in Xenopus oocytes.
1998,
Pubmed
,
Xenbase
Hassaine,
X-ray structure of the mouse serotonin 5-HT3 receptor.
2014,
Pubmed
Horenstein,
Reversal of agonist selectivity by mutations of conserved amino acids in the binding site of nicotinic acetylcholine receptors.
2007,
Pubmed
,
Xenbase
Horovitz,
Double-mutant cycles: a powerful tool for analyzing protein structure and function.
1996,
Pubmed
Kouvatsos,
Crystal structure of a human neuronal nAChR extracellular domain in pentameric assembly: Ligand-bound α2 homopentamer.
2016,
Pubmed
,
Xenbase
Lummis,
5-HT(3) receptors.
2012,
Pubmed
Lynagh,
Principles of agonist recognition in Cys-loop receptors.
2014,
Pubmed
Mallipeddi,
Interactions of acetylcholine binding site residues contributing to nicotinic acetylcholine receptor gating: role of residues Y93, Y190, K145 and D200.
2013,
Pubmed
Miles,
A coupled array of noncovalent interactions impacts the function of the 5-HT3A serotonin receptor in an agonist-specific way.
2012,
Pubmed
,
Xenbase
Miller,
Binding, activation and modulation of Cys-loop receptors.
2010,
Pubmed
Miller,
Crystal structure of a human GABAA receptor.
2014,
Pubmed
Morales-Perez,
X-ray structure of the human α4β2 nicotinic receptor.
2016,
Pubmed
Mukhtasimova,
Initial coupling of binding to gating mediated by conserved residues in the muscle nicotinic receptor.
2005,
Pubmed
Nasiripourdori,
Binding of long-chain alpha-neurotoxin would stabilize the resting state of nAChR: a comparative study with alpha-conotoxin.
2009,
Pubmed
Price,
A hydrogen bond in loop A is critical for the binding and function of the 5-HT3 receptor.
2008,
Pubmed
Shanata,
Using mutant cycle analysis to elucidate long-range functional coupling in allosteric receptors.
2012,
Pubmed
Sigel,
Structure, function, and modulation of GABA(A) receptors.
2012,
Pubmed
Taly,
Nicotinic receptors: allosteric transitions and therapeutic targets in the nervous system.
2009,
Pubmed
Thompson,
A single channel mutation alters agonist efficacy at 5-HT3A and 5-HT3AB receptors.
2013,
Pubmed
,
Xenbase
Thompson,
The structural basis of function in Cys-loop receptors.
2010,
Pubmed
Thompson,
The 5-HT3 receptor as a therapeutic target.
2007,
Pubmed
Thompson,
Locating an antagonist in the 5-HT3 receptor binding site using modeling and radioligand binding.
2005,
Pubmed
Unwin,
Refined structure of the nicotinic acetylcholine receptor at 4A resolution.
2005,
Pubmed
Venkatachalan,
A conserved salt bridge critical for GABA(A) receptor function and loop C dynamics.
2008,
Pubmed
,
Xenbase
Wyllie,
Taking the time to study competitive antagonism.
2007,
Pubmed
Xiu,
Nicotine binding to brain receptors requires a strong cation-pi interaction.
2009,
Pubmed
,
Xenbase
Zouridakis,
Crystal structures of free and antagonist-bound states of human α9 nicotinic receptor extracellular domain.
2014,
Pubmed
,
Xenbase