Role of the actin cytoskeleton in store-mediated calcium entry in glioma C6 cells.
The effects of actin cytoskeleton disruption by cytochalasin D and latrunculin A on Ca2+ signals evoked by ADP, UTP or thapsigargin were investigated in glioma C6 cells. Despite the profound alterations of the actin cytoskeleton architecture and cell morphology, ADP and UTP still produced cytosolic calcium elevation in this cell line. However, calcium mobilization from internal stores and Ca2+ influx through store-operated Ca2+ channels induced by ADP and UTP were strongly reduced. Cytochalasin D and latrunculin A also diminished extracellular Ca2+ influx in unstimulated glioma C6 cells previously incubated in Ca2+ free buffer. In contrast, the disruption of the actin cytoskeleton had no effect on thapsigargin-induced Ca2+ influx in this cell line. Both agonist- and thapsigargin-generated Ca2+ entry was significantly decreased by the blocker of store-operated Ca2+ channels, 2-aminoethoxydiphenylborate. The data reveal that two agonists and thapsigargin activate store-operated Ca2+ channels but the mechanism of activation seems to be different. While the agonists evoke a store-mediated Ca2+ entry that is dependent on the actin cytoskeleton, thapsigargin apparently activates an additional mechanism, which is independent of the disruption of the cytoskeleton.
Sabała
Pawelz
P
Laboratory of Signal Transduction, Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Str., Warsaw, Poland. sabala@nencki.gov.pl
Targos
Berenika
B
Caravelli
Antonella
A
Czajkowski
Rafał
R
Lim
Dmitri
D
Gragnaniello
Gianni
G
Santella
Luigia
L
Barańska
Jolanta
J
D000199:Actins / Q000378:metabolism*; D000244:Adenosine Diphosphate / Q000378:metabolism; D000818:Animals; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000502:physiology*; D002614:Chelating Agents / Q000378:metabolism; D015638:Cytochalasin D / Q000494:pharmacology; D003599:Cytoskeleton / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005456:Fluorescent Dyes / Q000378:metabolism; D016257:Fura-2 / Q000378:metabolism; D005910:Glioma; D018613:Microscopy, Confocal; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D051381:Rats; D019284:Thapsigargin / Q000494:pharmacology; D013844:Thiazoles / Q000494:pharmacology; D053778:Thiazolidines; D014407:Tumor Cells, Cultured; D014544:Uridine Triphosphate / Q000378:metabolism
D000199:Actins; D019086:Bridged Bicyclo Compounds, Heterocyclic; D002614:Chelating Agents; D004791:Enzyme Inhibitors; D005456:Fluorescent Dyes; D019384:Nucleic Acid Synthesis Inhibitors; D013844:Thiazoles; D053778:Thiazolidines; D015638:Cytochalasin D; D000244:Adenosine Diphosphate; D019284:Thapsigargin; C037067:latrunculin A; D002118:Calcium; D016257:Fura-2; D014544:Uridine Triphosphate