|
|
|
|
|
||
|
|||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | |||||
Journal of Cell Science, Vol 105, Issue 4 1131-1135, Copyright © 1993 by Company of Biologists
JOURNAL ARTICLES |
H Flaadt, E Jaworski and D Malchow
Fakultat faur Biologie, Universitat Konstanz, FRG.
Signal transduction in Dictyostelium for oriented movement and differentiation involves a fine tuning of the cytosolic Ca2+ concentration. We have previously shown that cAMP binding to the cell surface receptor elicits two cellular events: (i) to enhance Ca2+ entry across the plasma membrane; (ii) to increase Ca2+ uptake into Ca(2+)-sequestering organelles. Here we used permeabilised cells to show that cAMP-induced Ca2+ uptake in these cells was sensitive to the Ca2+ transport ATPase blocker 2,5-di-(tert-butyl)-1,4-hydroquinone (BHQ) and the vacuolar H(+)-ATPase inhibitor NBD-Cl. By contrast, bafilomycin A1 and vanadate, inhibitors of Ca2+ uptake into acidosomes in Dictyostelium, did not reduce the cAMP-induced Ca2+ uptake of permeabilised cells. GTP gamma S served as a tool to measure Ins(1,4,5)P3- (InsP3)-sensitive Ca2+ release. Following NBD-Cl or BHQ treatment Ca2+ release was reversibly inhibited. We conclude that the cAMP-controlled Ca2+ influx is directed into a NBD-Cl and BHQ-sensitive compartment, which comprises the InsP3-releasable pool. The acidosomal Ca2+ store seems to provide for additional Ca2+ if required.
This article has been cited by other articles:
|
|
 |
|
  C. Schlatterer, K. Happle, D. F. Lusche, and J. Sonnemann Cytosolic [Ca2+] Transients in Dictyostelium discoideum Depend on the Filling State of Internal Stores and on an Active Sarco/Endoplasmic Reticulum Calcium ATPase (SERCA) Ca2+ Pump J. Biol. Chem., April 30, 2004; 279(18): 18407 - 18414. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Marchesini, F. A. Ruiz, M. Vieira, and R. Docampo Acidocalcisomes Are Functionally Linked to the Contractile Vacuole of Dictyostelium discoideum J. Biol. Chem., March 1, 2002; 277(10): 8146 - 8153. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Schaloske, C. Schlatterer, and D. Malchow A Xestospongin C-sensitive Ca2+ Store Is Required for cAMP-induced Ca2+ Influx and cAMP Oscillations in Dictyostelium J. Biol. Chem., March 17, 2000; 275(12): 8404 - 8408. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J Moniakis, M. Coukell, and A Janiec Involvement of the Ca2+-ATPase PAT1 and the contractile vacuole in calcium regulation in Dictyostelium discoideum J. Cell Sci., January 2, 1999; 112(3): 405 - 414. [Abstract] [PDF]
|
|
|
|
|
|
J. Moniakis, M. B. Coukell, and A. Forer Molecular Cloning of an Intracellular P-type ATPase from Dictyostelium That Is Up-regulated in Calcium-adapted Cells J. Biol. Chem., November 24, 1995; 270(47): 28276 - 28281. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Lydan and D. Cotter The role of Ca2+ during spore germination in Dictyostelium: autoactivation is mediated by the mobilization of Ca2+ while amoebal emergence requires entry of external Ca2+ J. Cell Sci., January 5, 1995; 108(5): 1921 - 1930. [Abstract] [PDF]
|
|
|
|
|
|
R Schaloske, C Sordano, S Bozzaro, and D Malchow Stimulation of calcium influx by platelet activating factor in Dictyostelium J. Cell Sci., January 4, 1995; 108(4): 1597 - 1603. [Abstract] [PDF]
|
|
