Single-Channel Kinetic Analysis for Activation and Desensitization of Homomeric 5-HT3A Receptors

Autores
Corradi, Jeremias; Gumilar, Fernanda Andrea; Bouzat, Cecilia Beatriz
Año de publicación
2009
Idioma
inglés
Tipo de recurso
documento de conferencia
Estado
versión publicada
Descripción
The 5-HT3A receptor is a member of the Cys-loop family of ligand-gated ion channels. Due to its low conductance, kinetic analysis of this receptor has been restricted to the macroscopic level. We introduced mutations in the 5- HT3A subunit to obtain a high-conductance form so that single-channel currents can be detected. At all 5-HT concentrations (>0.1 mM) channel activity appears as opening events in quick succession forming bursts, which, in turn, coalesce into clusters. By combining single-channel and macroscopic data we generated a detailed kinetic model that perfectly describes activation, deactivation and de- sensitization. The model shows that full activation arises from receptors with three molecules of agonist bound. It also reveals an earlier conformational change of the fully-liganded receptor (flipping) that occurs while the channel is still closed. From this pre-open state the receptor enters into an open-closed cycle involving three open states, which conforms the cluster whose duration parallels the time constant of desensitization. This suggests that at a synapse the lifetime of the elementary response of 5-HT3A receptors is determined mainly by desensitization. Since the desensitized state is a stable state, the in- ter-response latency is expected to be prolonged. The present kinetic model provides a foundation for studying molecular mechanisms of drug action. We show that mutations at valine 100 of M4 affect opening and closing rates within the open-closed cycle. This reveals that the outermost transmembrane domain is important for appropriate gating and shows a high conservation of M4 function among members of this superfamily.
Fil: Corradi, Jeremias. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina
Fil: Gumilar, Fernanda Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina
Fil: Bouzat, Cecilia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina
53th Annual Meeting Biophysical Society
Boston
Estados Unidos
Biophysical Society
Materia
ION CHANNEL
NICOTINIC ACETYLCHOLINE RECEPTOR
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/252950
Acceder
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oai_identifier_str oai:ri.conicet.gov.ar:11336/252950
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Single-Channel Kinetic Analysis for Activation and Desensitization of Homomeric 5-HT3A ReceptorsCorradi, JeremiasGumilar, Fernanda AndreaBouzat, Cecilia BeatrizION CHANNELNICOTINIC ACETYLCHOLINE RECEPTORhttps://purl.org/becyt/ford/1.6https://purl.org/becyt/ford/1The 5-HT3A receptor is a member of the Cys-loop family of ligand-gated ion channels. Due to its low conductance, kinetic analysis of this receptor has been restricted to the macroscopic level. We introduced mutations in the 5- HT3A subunit to obtain a high-conductance form so that single-channel currents can be detected. At all 5-HT concentrations (>0.1 mM) channel activity appears as opening events in quick succession forming bursts, which, in turn, coalesce into clusters. By combining single-channel and macroscopic data we generated a detailed kinetic model that perfectly describes activation, deactivation and de- sensitization. The model shows that full activation arises from receptors with three molecules of agonist bound. It also reveals an earlier conformational change of the fully-liganded receptor (flipping) that occurs while the channel is still closed. From this pre-open state the receptor enters into an open-closed cycle involving three open states, which conforms the cluster whose duration parallels the time constant of desensitization. This suggests that at a synapse the lifetime of the elementary response of 5-HT3A receptors is determined mainly by desensitization. Since the desensitized state is a stable state, the in- ter-response latency is expected to be prolonged. The present kinetic model provides a foundation for studying molecular mechanisms of drug action. We show that mutations at valine 100 of M4 affect opening and closing rates within the open-closed cycle. This reveals that the outermost transmembrane domain is important for appropriate gating and shows a high conservation of M4 function among members of this superfamily.Fil: Corradi, Jeremias. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; ArgentinaFil: Gumilar, Fernanda Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; ArgentinaFil: Bouzat, Cecilia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina53th Annual Meeting Biophysical SocietyBostonEstados UnidosBiophysical SocietyCell Press2009info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/conferenceObjectReuniónJournalhttp://purl.org/coar/resource_type/c_5794info:ar-repo/semantics/documentoDeConferenciaapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/252950Single-Channel Kinetic Analysis for Activation and Desensitization of Homomeric 5-HT3A Receptors; 53th Annual Meeting Biophysical Society; Boston; Estados Unidos; 2009; 486a-487a0006-34951542-0086CONICET DigitalCONICETenghttps://ri.conicet.gov.ar/handle/11336/66139info:eu-repo/semantics/altIdentifier/url/https://www.cell.com/biophysj/issue?pii=S0006-3495(09)X0003-2#closeFullCoverInternacionalinfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-29T09:39:30Zoai:ri.conicet.gov.ar:11336/252950instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-09-29 09:39:31.042CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Single-Channel Kinetic Analysis for Activation and Desensitization of Homomeric 5-HT3A Receptors
title Single-Channel Kinetic Analysis for Activation and Desensitization of Homomeric 5-HT3A Receptors
spellingShingle Single-Channel Kinetic Analysis for Activation and Desensitization of Homomeric 5-HT3A Receptors
Corradi, Jeremias
ION CHANNEL
NICOTINIC ACETYLCHOLINE RECEPTOR
title_short Single-Channel Kinetic Analysis for Activation and Desensitization of Homomeric 5-HT3A Receptors
title_full Single-Channel Kinetic Analysis for Activation and Desensitization of Homomeric 5-HT3A Receptors
title_fullStr Single-Channel Kinetic Analysis for Activation and Desensitization of Homomeric 5-HT3A Receptors
title_full_unstemmed Single-Channel Kinetic Analysis for Activation and Desensitization of Homomeric 5-HT3A Receptors
title_sort Single-Channel Kinetic Analysis for Activation and Desensitization of Homomeric 5-HT3A Receptors
dc.creator.none.fl_str_mv Corradi, Jeremias
Gumilar, Fernanda Andrea
Bouzat, Cecilia Beatriz
author Corradi, Jeremias
author_facet Corradi, Jeremias
Gumilar, Fernanda Andrea
Bouzat, Cecilia Beatriz
author_role author
author2 Gumilar, Fernanda Andrea
Bouzat, Cecilia Beatriz
author2_role author
author
dc.subject.none.fl_str_mv ION CHANNEL
NICOTINIC ACETYLCHOLINE RECEPTOR
topic ION CHANNEL
NICOTINIC ACETYLCHOLINE RECEPTOR
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.6
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv The 5-HT3A receptor is a member of the Cys-loop family of ligand-gated ion channels. Due to its low conductance, kinetic analysis of this receptor has been restricted to the macroscopic level. We introduced mutations in the 5- HT3A subunit to obtain a high-conductance form so that single-channel currents can be detected. At all 5-HT concentrations (>0.1 mM) channel activity appears as opening events in quick succession forming bursts, which, in turn, coalesce into clusters. By combining single-channel and macroscopic data we generated a detailed kinetic model that perfectly describes activation, deactivation and de- sensitization. The model shows that full activation arises from receptors with three molecules of agonist bound. It also reveals an earlier conformational change of the fully-liganded receptor (flipping) that occurs while the channel is still closed. From this pre-open state the receptor enters into an open-closed cycle involving three open states, which conforms the cluster whose duration parallels the time constant of desensitization. This suggests that at a synapse the lifetime of the elementary response of 5-HT3A receptors is determined mainly by desensitization. Since the desensitized state is a stable state, the in- ter-response latency is expected to be prolonged. The present kinetic model provides a foundation for studying molecular mechanisms of drug action. We show that mutations at valine 100 of M4 affect opening and closing rates within the open-closed cycle. This reveals that the outermost transmembrane domain is important for appropriate gating and shows a high conservation of M4 function among members of this superfamily.
Fil: Corradi, Jeremias. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina
Fil: Gumilar, Fernanda Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina
Fil: Bouzat, Cecilia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina
53th Annual Meeting Biophysical Society
Boston
Estados Unidos
Biophysical Society
description The 5-HT3A receptor is a member of the Cys-loop family of ligand-gated ion channels. Due to its low conductance, kinetic analysis of this receptor has been restricted to the macroscopic level. We introduced mutations in the 5- HT3A subunit to obtain a high-conductance form so that single-channel currents can be detected. At all 5-HT concentrations (>0.1 mM) channel activity appears as opening events in quick succession forming bursts, which, in turn, coalesce into clusters. By combining single-channel and macroscopic data we generated a detailed kinetic model that perfectly describes activation, deactivation and de- sensitization. The model shows that full activation arises from receptors with three molecules of agonist bound. It also reveals an earlier conformational change of the fully-liganded receptor (flipping) that occurs while the channel is still closed. From this pre-open state the receptor enters into an open-closed cycle involving three open states, which conforms the cluster whose duration parallels the time constant of desensitization. This suggests that at a synapse the lifetime of the elementary response of 5-HT3A receptors is determined mainly by desensitization. Since the desensitized state is a stable state, the in- ter-response latency is expected to be prolonged. The present kinetic model provides a foundation for studying molecular mechanisms of drug action. We show that mutations at valine 100 of M4 affect opening and closing rates within the open-closed cycle. This reveals that the outermost transmembrane domain is important for appropriate gating and shows a high conservation of M4 function among members of this superfamily.
publishDate 2009
dc.date.none.fl_str_mv 2009
dc.type.none.fl_str_mv info:eu-repo/semantics/publishedVersion
info:eu-repo/semantics/conferenceObject
Reunión
Journal
http://purl.org/coar/resource_type/c_5794
info:ar-repo/semantics/documentoDeConferencia
status_str publishedVersion
format conferenceObject
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/252950
Single-Channel Kinetic Analysis for Activation and Desensitization of Homomeric 5-HT3A Receptors; 53th Annual Meeting Biophysical Society; Boston; Estados Unidos; 2009; 486a-487a
0006-3495
1542-0086
CONICET Digital
CONICET
url http://hdl.handle.net/11336/252950
identifier_str_mv Single-Channel Kinetic Analysis for Activation and Desensitization of Homomeric 5-HT3A Receptors; 53th Annual Meeting Biophysical Society; Boston; Estados Unidos; 2009; 486a-487a
0006-3495
1542-0086
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv https://ri.conicet.gov.ar/handle/11336/66139
info:eu-repo/semantics/altIdentifier/url/https://www.cell.com/biophysj/issue?pii=S0006-3495(09)X0003-2#closeFullCover
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
application/pdf
dc.coverage.none.fl_str_mv Internacional
dc.publisher.none.fl_str_mv Cell Press
publisher.none.fl_str_mv Cell Press
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
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score 13.069144

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