A rapid calcium influx during exocytosis in Paramecium cells is followed by a rise in cyclic GMP within 1 s

FEBS Letters

Knoll, Gerd¹  Plattner, Helmut¹  Kerboeuf, Daniel² 

[1] University of Konstanz, Faculty of Biology, POB 5560, D-7750 Konstanz, Germany;CNRS, Centre de Génétique Moléculaire, F-91198 Gif-sur-Yvette, France

关键词: Calcium;    Exocytosis;    Cyclic AMP;    Cyclic GMP;    Paramecium;    Veratridine;   

DOI  :  10.1016/0014-5793(92)80634-S

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The synchrony of trichocyst exocytosis in Paramecium allows temporal correlation of associated events. Using quenched flow we observed a Ca²⁺ influx concurrent with exocytosis within 80 ms after stimulation with the secretagogue aminoethyldextran. Cyclic AMP did not change in depency of stimulation. Cyclic GMP transiently increased after 500 ms, culminating at 2 s, and thus considerably lags behind exocytosis induction and influx of Ca²⁺. Both Ca²⁺ influx and rise in cGMP are known to be induceable also by Ba²⁺ or veratridine, allegedly via the opening of ciliary Ca²⁺ channels. However, only veratridine stimulated exocytosis. We conclude that both aminoethyldextran and veratridine induce an exocytosis-associated Ca²⁺ influx, which is responsible for the rise in cGMP, through an as yet unknown pathway.

【 授权许可】

Unknown