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La corriente de calcio operada por el almacén I(CRAC): activación no lineal por InsP3 y disociación de la liberación
A B Parekh1, A Fleig, R Penner
1Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany.
Cell
|June 13, 1997
Resumen
La activación de la corriente de calcio operada por almacenamiento (CRAC) por la liberación de calcio es altamente no lineal. Las células pueden disociar la liberación de calcio de la afluencia, utilizando almacenes intracelulares distintos para una señalización precisa de calcio.
Área de la Ciencia:
- Fisiología celular La fisiología celular.
- La señalización del calcio.
Sus antecedentes:
- La entrada de calcio operada por almacenamiento (SOCE) es crucial para la homeostasis del calcio celular.
- Los mecanismos precisos que vinculan la liberación de calcio intracelular con la activación de SOCE aún no se comprenden por completo.
Objetivo del estudio:
- Investigar la relación entre la liberación de calcio intracelular y la activación de la corriente de calcio operada en el almacén (CRAC)).
- Determinar las sensibilidades diferenciales de la liberación y afluencia de calcio al inositol trisfosfato (InsP3).
Principales métodos:
- La electrofisiología de la pinza de parche se empleó para medir I ((CRAC).).
- Los experimentos involucraron diferentes concentraciones de agonistas e InsP3 para estimular la liberación y la afluencia de calcio.
Principales resultados:
- Tanto la activación agonista como la activación mediada por InsP3 de I ((CRAC) exhibieron una alta no linealidad, ocurriendo dentro de un rango de concentración estrecho.
- La liberación y la afluencia de calcio mostraron sensibilidad diferencial a InsP3, con bajas concentraciones que favorecen la liberación y las concentraciones micromolares requeridas para la afluencia.
- Estos hallazgos sugieren que almacenes de calcio intracelulares funcionalmente distintos regulan la liberación y la afluencia.
Conclusiones:
- Las células pueden disociar la liberación de calcio de la afluencia de calcio.
- La existencia de almacenes funcionalmente distintos permite un control celular preciso sobre las vías de señalización del calcio.
- Este mecanismo permite a las células adaptar la señalización del calcio para satisfacer demandas fisiológicas específicas.
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