Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
30
pubmed:dateCreated
2011-7-28
pubmed:abstractText
The neuronal ?4?2 nicotinic acetylcholine receptors exist as two distinct subtypes, (?4)(2)(?2)(3) and (?4)(3)(?2)(2), and biphasic responses to acetylcholine and other agonists have been ascribed previously to coexistence of these two receptor subtypes. We offer a novel and radical explanation for the observation of two distinct agonist sensitivities. Using different expression ratios of mammalian ?4 and ?2 subunits and concatenated constructs, we demonstrate that a biphasic response is an intrinsic functional property of the (?4)(3)(?2)(2) receptor. In addition to two high-sensitivity sites at ?4?2 interfaces, the (?4)(3)(?2)(2) receptor contains a third low-sensitivity agonist binding site in the ?4?4 interface. Occupation of this site is required for full activation and is responsible for the widened dynamic response range of this receptor subtype. By site-directed mutagenesis, we show that three residues, which differ between the ?4?2 and ?4?4 sites, control agonist sensitivity. The results presented here provide a basic insight into the function of pentameric ligand-gated ion channels, which enables modulation of the receptors with hitherto unseen precision; it becomes possible to rationally design therapeutics targeting subpopulations of specific receptor subtypes.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
1529-2401
pubmed:author
pubmed:issnType
Electronic
pubmed:day
27
pubmed:volume
31
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
10759-66
pubmed:meshHeading
pubmed-meshheading:21795528-Acetylcholine, pubmed-meshheading:21795528-Animals, pubmed-meshheading:21795528-Azepines, pubmed-meshheading:21795528-Binding Sites, pubmed-meshheading:21795528-Cholinergic Agonists, pubmed-meshheading:21795528-Dose-Response Relationship, Drug, pubmed-meshheading:21795528-Larva, pubmed-meshheading:21795528-Membrane Potentials, pubmed-meshheading:21795528-Models, Molecular, pubmed-meshheading:21795528-Mutagenesis, Site-Directed, pubmed-meshheading:21795528-Oocytes, pubmed-meshheading:21795528-Protein Binding, pubmed-meshheading:21795528-Protein Subunits, pubmed-meshheading:21795528-Pyridines, pubmed-meshheading:21795528-Receptors, Nicotinic, pubmed-meshheading:21795528-Sensitivity and Specificity, pubmed-meshheading:21795528-Sequence Alignment, pubmed-meshheading:21795528-Transfection
pubmed:year
2011
pubmed:articleTitle
Unraveling the high- and low-sensitivity agonist responses of nicotinic acetylcholine receptors.
pubmed:affiliation
Department of Medicinal Chemistry, Faculty of Pharmaceutical Sciences, University of Copenhagen, DK-2100 Copenhagen, Denmark.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't