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El hemo puede unirse e inhibir los canales Slo1 BK dependientes del calcio de los mamíferos
Xiang Dong Tang1, Rong Xu, Mark F Reynolds
1Department of Physiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
Nature
|October 3, 2003
Resumen
El hemo, esencial para las proteínas, regula directamente los canales Slo1 BK dependientes del calcio de gran conductividad. Esta unión inhibe las corrientes de potasio, revelando el nuevo papel del hemo como una molécula de señalización aguda.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- La neurociencia es la neurociencia.
- Biología Molecular Biología Molecular
Sus antecedentes:
- El hemo es un cofactor vital en las hemeproteínas, esencial para las reacciones redox.
- El hemo se incorpora enzimáticamente a las apo-hemoproteínas durante la biogénesis.
- Los canales Slo1 BK dependientes del calcio de gran conductividad presentan un motivo de unión al hemo conservado.
Objetivo del estudio:
- Investigar la interacción directa entre los canales BK hemo y Slo1.
- Para aclarar las consecuencias funcionales de la unión del hemo en la actividad del canal BK.
Principales métodos:
- Grabaciones electrofisiológicas de canales BK de tipo salvaje de Slo1 humano y cerebro de rata clonados.
- Análisis de evidencia estructural de la interacción entre el hemo-canal.
Principales resultados:
- El hemo se une directamente a la proteína del canal Slo1 (hSlo1) humano tanto en estados oxidados como reducidos.
- La unión del hemo inhibe profundamente las corrientes K+ transmembrana.
- La inhibición se produce mediante la disminución de la frecuencia de apertura del canal.
Conclusiones:
- El hemo regula directamente los canales Slo1 BK.
- Esta interacción revela una nueva función del hemo como una molécula de señalización aguda.
- Los canales BK son un objetivo directo para la regulación mediada por el hemo.
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