Regulation of BK channel by tungstate and its relevance for the control of vascular tone and intracellular signalling

The large-conductance Ca2+- and voltage-gated K+ (BK) channel containing the pore-forming and the regulatory B1 subunits play a pivotal role in the control of arterial tone and modification of channel function is associated to changes in blood pressure in both animal models and humans. Tungstate, a...

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Detalles Bibliográficos
Autor: Fernández Mariño, Ana Isabel
Tipo de recurso: tesis doctoral
Estado:Versión publicada
Fecha de publicación:2013
País:España
Institución:CBUC, CESCA
Repositorio:TDR. Tesis Doctorales en Red
OAI Identifier:oai:www.tdx.cat:10803/283477
Acceso en línea:http://hdl.handle.net/10803/283477
Access Level:acceso abierto
Palabra clave:BK channels
Tungstate
BK B1 subunit
Artery
Vasodilation
Hypertension
G proteins
ERK1/2
577
Descripción
Sumario:The large-conductance Ca2+- and voltage-gated K+ (BK) channel containing the pore-forming and the regulatory B1 subunits play a pivotal role in the control of arterial tone and modification of channel function is associated to changes in blood pressure in both animal models and humans. Tungstate, a compound with antidiabetic and antiobesity properties, also reduces blood pressure in experimental animal models of both hypertension and metabolic syndrome, although the underlying mechanisms are not completely understood. This Thesis evaluates the effect of tungstate on BK channel function and its relevance for both the regulation of vascular resistance and intracellular signaling. Our results show that tungstate activates BK channels in a - and Mg2+-dependent manner and induces vasodilatation only in mouse arteries that express the BK B1 subunit. Our functional and comparative structural analysis suggest that, although the tungstate interaction site is located in the BK subunit, its positive effect on the channel requires residues of the B1 subunit extracellular loop that stabilize the active configuration of the voltage sensor. In addition, we have found that tungstate-induced, Gi/o protein-mediated ERK phosphorylation is enhanced by BK B1 channels.