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Monitoring ER/SR Calcium Release with the Targeted Ca2+ Sensor CatchER+
Published on: May 19, 2017
La repetición I del receptor de dihidropiridina es crítica para determinar la cinética de activación del canal de
1Department of Medical Chemistry, Kyoto University Faculty of Medicine, Japan.
Nature
|August 29, 1991
Resumen
La repetición I de los canales de calcio controla su velocidad de activación. Este hallazgo revela cómo los cambios estructurales en los canales de calcio controlados por voltaje influyen en su función, diferenciando entre los tipos de músculo esquelético y cardíaco.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- La biofísica es la biofísica.
- Fisiología cardiovascular fisiología cardiovascular.
Sus antecedentes:
- La activación del canal iónico implica cambios conformacionales.
- Los canales de calcio regulados por voltaje (VGCC) comparten un motivo estructural común con cuatro repeticiones homólogas (I-IV).
- Cada repetición contiene un segmento S4 de detección de voltaje, lo que sugiere funciones específicas de repetición en la activación.
Objetivo del estudio:
- Para investigar la base molecular de la activación del VGCC.
- Determinar qué repetición estructural dicta la distinta cinética de activación de los canales de calcio esquelético y cardíaco.
Principales métodos:
- Construcción de ADNs complementarios que codifican los canales Ca2+ quiméricos.
- Intercambio de repeticiones homólogas (I-IV) entre los receptores esqueléticos y cardíacos de dihidropiridina.
- Análisis de la cinética de activación en los canales quiméricos expresados.
Principales resultados:
- Se construyeron con éxito canales de Ca2+ quiméricos.
- Repito I fue identificado como el determinante de la velocidad de activación.
- La sustitución de la repetición I del receptor del músculo esquelético por la contraparte cardíaca dio lugar a una activación rápida, similar a la cardíaca.
Conclusiones:
- La primera repetición (Repetición I) del receptor de dihidropiridina es crítica para determinar la tasa de activación del canal Ca2+.
- Este hallazgo aclara la base estructural para la cinética de activación diferencial entre los canales de calcio del músculo esquelético y cardíaco.
- Repito que I juega un papel clave en las transiciones conformacionales subyacentes al canal de entrada.
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