DMCA
Facilitation of membrane fusion during exocytosis and exocytosis-coupled endocytosis and acceleration of “ghost” detachment in Paramecium by extracellular calcium. A quenched-flow/freeze-fracture analysis (1997)
| Venue: | J. Membrane Biol |
| Citations: | 13 - 8 self |
BibTeX
@ARTICLE{Plattner97facilitationof,
author = {H. Plattner and C. Braun and J. Hentschel},
title = {Facilitation of membrane fusion during exocytosis and exocytosis-coupled endocytosis and acceleration of “ghost” detachment in Paramecium by extracellular calcium. A quenched-flow/freeze-fracture analysis},
journal = {J. Membrane Biol},
year = {1997}
}
Share
 |
 |
 |
 |
||
OpenURL
Abstract
Abstract. We had previously shown that an influx of extracellular Ca2+ (Ca2+e), though it occurs, is not strictly required for aminoethyldextran (AED)-triggered exocy-totic membrane fusion in Paramecium. We now ana-lyze, by quenched-flow/freeze-fracture, to what extent Ca2+e contributes to exocytotic and exocytosis-coupled endocytotic membrane fusion, as well as to detachment of ‘‘ghosts’ ’ — a process difficult to analyze by any other method or in any other system. Maximal exocy-totic membrane fusion (analyzed within 80 msec) occurs readily in the presence of [Ca2+]e ù 5 × 10−6 M, while normally a [Ca2+]e 4 0.5 mM is in the medium. A new finding is that exocytosis and endocytosis is significantly stimulated by increasing [Ca2+]e even beyond levels usu-ally available to cells. Quenching of [Ca2+]e by EGTA
Keyphrases
quenched-flow freeze-fracture analysis exocytosis-coupled endocytosis membrane fusion ghost detachment extracellular calcium maximal exocy-totic membrane fusion extracellular ca2 exocytosis-coupled endocytotic membrane fusion quenched-flow freeze-fracture new finding extent ca2 contributes exocy-totic membrane fusion
