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Characterization of G Protein-coupled Receptors by a Fluorescence-based Calcium Mobilization Assay
Published on: July 28, 2014
La activación de una proteína G promueve respuestas agonistas a los ligandos de los canales de calcio
1Department of Pharmacology, St George's Hospital Medical School, London, UK.
Nature
|December 24, 1987
Resumen
Las proteínas de unión al nucleótido de guanina (G) modulan la actividad del canal de calcio. Las proteínas G activadas mejoran las corrientes de los canales de calcio, potenciando las interacciones de ligandos e influyendo en las respuestas celulares.
Área de la Ciencia:
- La neurociencia es la neurociencia.
- Biología Molecular Biología Molecular
- Farmacología Farmacología.
Sus antecedentes:
- La activación de la proteína de unión al nucleótido de guanina (G) es crucial para la inhibición mediada por el receptor de los canales de calcio activados por voltaje.
- Los análogos de GTP potencian los agonistas de los receptores e inhiben las corrientes de calcio en las neuronas del ganglio de la raíz dorsal (DRG).
- Un componente de corriente de canal de calcio de tipo L sostenido es resistente a la inhibición por guanosina 5'-O-3-tiotrifosfato (GTP-gamma-S).
Objetivo del estudio:
- Para investigar la interacción entre los antagonistas de los canales de calcio y las corrientes modificadas por GTP-gamma-S.
- Para explorar la influencia de las proteínas G activadas en las interacciones de los ligandos de los canales de calcio.
- Proporcionar evidencia electrofisiológica de los efectos del nucleótido de guanina en las respuestas celulares a los ligandos de los canales de calcio.
Principales métodos:
- Registros electrofisiológicos de las corrientes del canal de calcio en neuronas DRG cultivadas.
- Aplicación de análogos de GTP y antagonistas de los canales de calcio (D600, nifedipina, diltiazem).
- Evaluación del efecto de la toxina de la tos ferina en las corrientes modificadas por GTP-gamma-S.
Principales resultados:
- Los antagonistas de los canales de calcio potenciaron marcadamente las corrientes de los canales de calcio en presencia de GTP-gamma-S. interno.
- Esta potenciación fue abolida por la toxina de la tos ferina, lo que indica la participación de la proteína G (Gi / Go).
- Las proteínas G activadas interactúan con los canales de calcio, mejorando la acción del ligando.
Conclusiones:
- Las proteínas G activadas pueden interactuar con los canales de calcio, potenciando los efectos de los ligandos de los canales.
- Esta interacción mejora la unión de ligandos en los sitios agonistas en los canales de estado de reposo.
- Demuestra la primera evidencia electrofisiológica de nucleótidos de guanina que influyen en las respuestas celulares a los ligandos de los canales de calcio.
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