Single-channel study of the binding-gating coupling in the slowly desensitizing chimeric alpha7-5HT3A receptor.
We have studied the role of the highly conserved residue alphaLysine145 in the early steps of activation by acetylcholine of the nicotinic acetylcholine receptor (nAChR). Both macroscopic and single-channel currents were recorded in the slowly desensitizing chimeric mutant receptor alpha7V201-5HT3A/R432Q/R436D/R440A, made of alpha7 nAChRs and serotonin receptors of subtype 3A (ch1), and its corresponding mutant K145A (ch1/K145A) expressed in Xenopus oocytes. Mutant ch1/K145A receptors had a reduced gating function similar to that produced by the same mutation in the wild type receptor alpha7. The mutated receptor has reduced opening rate constants, beta, and increased closing rate constants, alpha.
Bernal
José Antonio
JA
Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d'Alacant, 03550 Alicante, Spain.
Mulet
José
J
Castillo
Mar
M
Criado
Manuel
M
Sala
Francisco
F
Sala
Salvador
S
D000470:Alkaloids / Q000494:pharmacology; D000818:Animals; D001392:Azocines / Q000494:pharmacology; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology; D002217:Carbachol / Q000494:pharmacology; D002417:Cattle; D018679:Cholinergic Agonists / Q000494:pharmacology; D015640:Ion Channel Gating / Q000187:drug effects / Q000502:physiology*; D008954:Models, Biological; D009538:Nicotine / Q000494:pharmacology; D018408:Patch-Clamp Techniques; D011485:Protein Binding; D011725:Pyridines / Q000494:pharmacology; D011807:Quinolizines / Q000494:pharmacology; D011978:Receptors, Nicotinic / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D044406:Receptors, Serotonin, 5-HT3 / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000819:agonists / Q000378:metabolism* / Q000502:physiology; D058827:Serotonin 5-HT3 Receptor Agonists; D014981:Xenopus; D064569:alpha7 Nicotinic Acetylcholine Receptor; D000093843:Quinolizidine Alkaloids
D000470:Alkaloids; D001392:Azocines; D019086:Bridged Bicyclo Compounds, Heterocyclic; D002217:Carbachol; D018679:Cholinergic Agonists; D009538:Nicotine; D011725:Pyridines; D011807:Quinolizines; D011978:Receptors, Nicotinic; D044406:Receptors, Serotonin, 5-HT3; D011993:Recombinant Fusion Proteins; D058827:Serotonin 5-HT3 Receptor Agonists; D064569:alpha7 Nicotinic Acetylcholine Receptor; C004712:cytisine; D000093843:Quinolizidine Alkaloids; C082748:epibatidine