The relative relevance of phosphorylation of the Thr¹⁷ residue of phospholamban is different at different levels of β-adrenergic stimulation

Autores
Said, María Matilde; Mundiña-Weilenmann, Cecilia; Vittone, Leticia Beatriz; Mattiazzi, Alicia Ramona
Año de publicación
2002
Idioma
español castellano
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Contractility and relaxation measurements were combined with the determination of total phospholamban (PLB) phosphorylation and the immunodetection of PLB-phosphorylation sites in the intact, beating rat heart to identify the contributions of PLB phosphorylation at the Thr¹⁷ and Ser¹⁶ residues at different levels of β-adrenoceptor stimulation. Whereas with 30-300 nM isoproterenol, phosphorylation of Thr¹⁷, the Ca²⁺-calmodulin-dependent protein kinase-II (CaMKII) site and Ser¹⁶, the protein kinase A (PKA) site, contributed approximately 50% each to PLB phosphorylation, and both participated in the relaxant action of isoproterenol, at lower a level of β-adrenoceptor stimulation (isoproterenol 0.3-3 nM), both effects were exclusively due to Ser¹⁶ phosphorylation. Increasing [Ca]o at 3 nM isoproterenol, to obtain an increase in contractility comparable to that produced by 30 nM isoproterenol, significantly increased Thr¹⁷ phosphorylation and the relaxant effect produced by 3 nM isoproterenol. An increase in Thr¹⁷ phosphorylation and in the relaxant effect of 3 nM isoproterenol was also obtained by phosphatase inhibition (okadaic acid). In this case, Ser¹⁶ phosphorylation was also increased. Moreover, perfusion with 30 nM isoproterenol in the presence of the PKA inhibitor H-89 decreased phosphorylation at both PLB residues and diminished the inotropic and relaxant responses to the β-agonist. The relative contribution of Thr¹⁷ phosphorylation to the isoproterenol-induced phosphorylation of PLB and relaxation thus increased with the level of β-adrenoceptor stimulation and the consequent increase in PKA activity. The lack of Thr¹⁷ phosphorylation at low isoproterenol concentrations might therefore be attributed to a level of PKA activity insufficient to increase [Ca]i to activate the CaMKII system and/or to inhibit the phosphatase that dephosphorylates PLB.
Centro de Investigaciones Cardiovasculares
Materia
Medicina
Phospholamban phosphorylation sites
β-Adrenoceptor stimulation
Myocardial relaxation
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by/4.0/
Repositorio
SEDICI (UNLP)
Institución
Universidad Nacional de La Plata
OAI Identificador
oai:sedici.unlp.edu.ar:10915/144219

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spelling The relative relevance of phosphorylation of the Thr¹⁷ residue of phospholamban is different at different levels of β-adrenergic stimulationSaid, María MatildeMundiña-Weilenmann, CeciliaVittone, Leticia BeatrizMattiazzi, Alicia RamonaMedicinaPhospholamban phosphorylation sitesβ-Adrenoceptor stimulationMyocardial relaxationContractility and relaxation measurements were combined with the determination of total phospholamban (PLB) phosphorylation and the immunodetection of PLB-phosphorylation sites in the intact, beating rat heart to identify the contributions of PLB phosphorylation at the Thr¹⁷ and Ser¹⁶ residues at different levels of β-adrenoceptor stimulation. Whereas with 30-300 nM isoproterenol, phosphorylation of Thr¹⁷, the Ca²⁺-calmodulin-dependent protein kinase-II (CaMKII) site and Ser¹⁶, the protein kinase A (PKA) site, contributed approximately 50% each to PLB phosphorylation, and both participated in the relaxant action of isoproterenol, at lower a level of β-adrenoceptor stimulation (isoproterenol 0.3-3 nM), both effects were exclusively due to Ser¹⁶ phosphorylation. Increasing [Ca]<sub>o</sub> at 3 nM isoproterenol, to obtain an increase in contractility comparable to that produced by 30 nM isoproterenol, significantly increased Thr¹⁷ phosphorylation and the relaxant effect produced by 3 nM isoproterenol. An increase in Thr¹⁷ phosphorylation and in the relaxant effect of 3 nM isoproterenol was also obtained by phosphatase inhibition (okadaic acid). In this case, Ser¹⁶ phosphorylation was also increased. Moreover, perfusion with 30 nM isoproterenol in the presence of the PKA inhibitor H-89 decreased phosphorylation at both PLB residues and diminished the inotropic and relaxant responses to the β-agonist. The relative contribution of Thr¹⁷ phosphorylation to the isoproterenol-induced phosphorylation of PLB and relaxation thus increased with the level of β-adrenoceptor stimulation and the consequent increase in PKA activity. The lack of Thr¹⁷ phosphorylation at low isoproterenol concentrations might therefore be attributed to a level of PKA activity insufficient to increase [Ca]<sub>i</sub> to activate the CaMKII system and/or to inhibit the phosphatase that dephosphorylates PLB.Centro de Investigaciones Cardiovasculares2002-08info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf801-809http://sedici.unlp.edu.ar/handle/10915/144219spainfo:eu-repo/semantics/altIdentifier/issn/0031-6768info:eu-repo/semantics/altIdentifier/issn/1432-2013info:eu-repo/semantics/altIdentifier/doi/10.1007/s00424-002-0885-yinfo:eu-repo/semantics/altIdentifier/pmid/12355181info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by/4.0/Creative Commons Attribution 4.0 International (CC BY 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-09-29T11:32:26Zoai:sedici.unlp.edu.ar:10915/144219Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:32:27.101SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv The relative relevance of phosphorylation of the Thr¹⁷ residue of phospholamban is different at different levels of β-adrenergic stimulation
title The relative relevance of phosphorylation of the Thr¹⁷ residue of phospholamban is different at different levels of β-adrenergic stimulation
spellingShingle The relative relevance of phosphorylation of the Thr¹⁷ residue of phospholamban is different at different levels of β-adrenergic stimulation
Said, María Matilde
Medicina
Phospholamban phosphorylation sites
β-Adrenoceptor stimulation
Myocardial relaxation
title_short The relative relevance of phosphorylation of the Thr¹⁷ residue of phospholamban is different at different levels of β-adrenergic stimulation
title_full The relative relevance of phosphorylation of the Thr¹⁷ residue of phospholamban is different at different levels of β-adrenergic stimulation
title_fullStr The relative relevance of phosphorylation of the Thr¹⁷ residue of phospholamban is different at different levels of β-adrenergic stimulation
title_full_unstemmed The relative relevance of phosphorylation of the Thr¹⁷ residue of phospholamban is different at different levels of β-adrenergic stimulation
title_sort The relative relevance of phosphorylation of the Thr¹⁷ residue of phospholamban is different at different levels of β-adrenergic stimulation
dc.creator.none.fl_str_mv Said, María Matilde
Mundiña-Weilenmann, Cecilia
Vittone, Leticia Beatriz
Mattiazzi, Alicia Ramona
author Said, María Matilde
author_facet Said, María Matilde
Mundiña-Weilenmann, Cecilia
Vittone, Leticia Beatriz
Mattiazzi, Alicia Ramona
author_role author
author2 Mundiña-Weilenmann, Cecilia
Vittone, Leticia Beatriz
Mattiazzi, Alicia Ramona
author2_role author
author
author
dc.subject.none.fl_str_mv Medicina
Phospholamban phosphorylation sites
β-Adrenoceptor stimulation
Myocardial relaxation
topic Medicina
Phospholamban phosphorylation sites
β-Adrenoceptor stimulation
Myocardial relaxation
dc.description.none.fl_txt_mv Contractility and relaxation measurements were combined with the determination of total phospholamban (PLB) phosphorylation and the immunodetection of PLB-phosphorylation sites in the intact, beating rat heart to identify the contributions of PLB phosphorylation at the Thr¹⁷ and Ser¹⁶ residues at different levels of β-adrenoceptor stimulation. Whereas with 30-300 nM isoproterenol, phosphorylation of Thr¹⁷, the Ca²⁺-calmodulin-dependent protein kinase-II (CaMKII) site and Ser¹⁶, the protein kinase A (PKA) site, contributed approximately 50% each to PLB phosphorylation, and both participated in the relaxant action of isoproterenol, at lower a level of β-adrenoceptor stimulation (isoproterenol 0.3-3 nM), both effects were exclusively due to Ser¹⁶ phosphorylation. Increasing [Ca]<sub>o</sub> at 3 nM isoproterenol, to obtain an increase in contractility comparable to that produced by 30 nM isoproterenol, significantly increased Thr¹⁷ phosphorylation and the relaxant effect produced by 3 nM isoproterenol. An increase in Thr¹⁷ phosphorylation and in the relaxant effect of 3 nM isoproterenol was also obtained by phosphatase inhibition (okadaic acid). In this case, Ser¹⁶ phosphorylation was also increased. Moreover, perfusion with 30 nM isoproterenol in the presence of the PKA inhibitor H-89 decreased phosphorylation at both PLB residues and diminished the inotropic and relaxant responses to the β-agonist. The relative contribution of Thr¹⁷ phosphorylation to the isoproterenol-induced phosphorylation of PLB and relaxation thus increased with the level of β-adrenoceptor stimulation and the consequent increase in PKA activity. The lack of Thr¹⁷ phosphorylation at low isoproterenol concentrations might therefore be attributed to a level of PKA activity insufficient to increase [Ca]<sub>i</sub> to activate the CaMKII system and/or to inhibit the phosphatase that dephosphorylates PLB.
Centro de Investigaciones Cardiovasculares
description Contractility and relaxation measurements were combined with the determination of total phospholamban (PLB) phosphorylation and the immunodetection of PLB-phosphorylation sites in the intact, beating rat heart to identify the contributions of PLB phosphorylation at the Thr¹⁷ and Ser¹⁶ residues at different levels of β-adrenoceptor stimulation. Whereas with 30-300 nM isoproterenol, phosphorylation of Thr¹⁷, the Ca²⁺-calmodulin-dependent protein kinase-II (CaMKII) site and Ser¹⁶, the protein kinase A (PKA) site, contributed approximately 50% each to PLB phosphorylation, and both participated in the relaxant action of isoproterenol, at lower a level of β-adrenoceptor stimulation (isoproterenol 0.3-3 nM), both effects were exclusively due to Ser¹⁶ phosphorylation. Increasing [Ca]<sub>o</sub> at 3 nM isoproterenol, to obtain an increase in contractility comparable to that produced by 30 nM isoproterenol, significantly increased Thr¹⁷ phosphorylation and the relaxant effect produced by 3 nM isoproterenol. An increase in Thr¹⁷ phosphorylation and in the relaxant effect of 3 nM isoproterenol was also obtained by phosphatase inhibition (okadaic acid). In this case, Ser¹⁶ phosphorylation was also increased. Moreover, perfusion with 30 nM isoproterenol in the presence of the PKA inhibitor H-89 decreased phosphorylation at both PLB residues and diminished the inotropic and relaxant responses to the β-agonist. The relative contribution of Thr¹⁷ phosphorylation to the isoproterenol-induced phosphorylation of PLB and relaxation thus increased with the level of β-adrenoceptor stimulation and the consequent increase in PKA activity. The lack of Thr¹⁷ phosphorylation at low isoproterenol concentrations might therefore be attributed to a level of PKA activity insufficient to increase [Ca]<sub>i</sub> to activate the CaMKII system and/or to inhibit the phosphatase that dephosphorylates PLB.
publishDate 2002
dc.date.none.fl_str_mv 2002-08
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
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info:eu-repo/semantics/altIdentifier/issn/1432-2013
info:eu-repo/semantics/altIdentifier/doi/10.1007/s00424-002-0885-y
info:eu-repo/semantics/altIdentifier/pmid/12355181
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International (CC BY 4.0)
eu_rights_str_mv openAccess
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Creative Commons Attribution 4.0 International (CC BY 4.0)
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instname_str Universidad Nacional de La Plata
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