Internal calcium release and activation of sea urchin eggs by cGMP are independent of the phosphoinositide signaling pathway.
Mol Biol Cell
; 3(3): 373-83, 1992 Mar.
Article
en En
| MEDLINE
| ID: mdl-1320962
We show that microinjecting cyclic GMP (cGMP) into unfertilized sea urchin eggs activates them by stimulating a rise in the intracellular free calcium ion concentration ([Ca2+]i). The increase in [Ca2+]i is similar in both magnitude and duration to the transient that activates the egg at fertilization. It is due to mobilization of calcium from intracellular stores but is not prevented by the inositol trisphosphate (InsP3) antagonist heparin. Furthermore, cGMP does not stimulate the eggs Na+/H+ antiport when the [Ca2+]i transient is blocked by the calcium chelator bis-(O-aminophenoxy)-N,N,N',N'-tetraacetic acid (BAPTA), suggesting that cGMP does not activate eggs by interacting with the their phosphoinositide signaling pathway. However, the [Ca2+]i increase and activation are prevented in eggs in which the InsP3-sensitive calcium stores have been emptied by the prior microinjection of the InsP3 analogue inositol 1,4,5-trisphosphorothioate. These data indicate that cGMP activates eggs by stimulating the release of calcium from an InsP3-sensitive calcium store via a novel, though unidentified, route independent of the InsP3 receptor.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Óvulo
/
Transducción de Señal
/
Calcio
/
GMP Cíclico
Límite:
Animals
Idioma:
En
Revista:
Mol Biol Cell
Asunto de la revista:
BIOLOGIA MOLECULAR
Año:
1992
Tipo del documento:
Article
País de afiliación:
Reino Unido
Pais de publicación:
Estados Unidos