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La estructura cristalina del canal iónico P2X(4) de entrada ATP en el estado cerrado
Toshimitsu Kawate1, Jennifer Carlisle Michel, William T Birdsong
1Vollum Institute, Oregon Health and Science University, 3181 Southwest Sam Jackson Park Road, Oregon 97239, USA.
Nature
|July 31, 2009
Resumen
Los conocimientos estructurales sobre los receptores P2X revelan su forma trímera en forma de cáliz y nuevos sitios de unión al ATP. Esta investigación proporciona una base molecular para comprender cómo la unión de ATP abre estos canales iónicos cruciales.
Área de la Ciencia:
- La biofísica es la biofísica.
- Biología Estructural Biología estructural.
- La neurociencia es la neurociencia.
Sus antecedentes:
- Los receptores P2X son canales catiónicos cerrados por ATP extracelular, involucrados en procesos fisiológicos vitales.
- Su estructura única carece de la homología conocida de la proteína del canal iónico, lo que dificulta la comprensión de sus mecanismos de entrada.
Objetivo del estudio:
- Para dilucidar la estructura molecular del receptor P2X(4) del pez cebra en su estado de reposo.
- Proporcionar una base estructural para la comprensión de la función del receptor P2X, incluida la unión de ligandos y la permeación iónica.
Principales métodos:
- Se utilizó cristalografía de rayos X para determinar la estructura del receptor P2X(4) del pez cebra.
- Análisis de la estructura trímera, las interfaces de las subunidades y la región de los poros.
Principales resultados:
- El receptor P2X(4) del pez cebra adopta una conformación trímera en forma de cáliz.
- Se identificaron tres sitios no canónicos de unión de ATP intersubunitaria.
- Caracterizó la puerta del canal iónico dentro del dominio transmembrana.
Conclusiones:
- Las estructuras determinadas ofrecen una base molecular para el encierro y el ensamblaje del receptor P2X.
- La unión de ATP probablemente induce cambios conformacionales, lo que lleva a la apertura del canal iónico.
- Estos hallazgos son cruciales para comprender las diversas funciones fisiológicas de los receptores P2X.
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