[Effect of latrunculin B, jasplakinolide and brefeldin A on the store-dependent Ca2+ entry in macrophages].
Using Fura-2AM microfluorimetry, effect of actin filament modifiers and vesicular trafficking inhibitor on the store-dependent Ca2+ entry induced by purinergic agonists (ATP, UTP) and endoplasmic Ca2+-ATPase inhibitors (thapsigargin, cyclopiazonic acid) in rat peritoneal macrophages was investigated. It was shown that inhibition of actin polymerization by latrunculin B had a biphasic time-dependent effect on Ca2+ entry, showing an initial potentiation followed by inhibition of Ca2+ entry. Moreover, addition of latrunculin B after induction of store-dependent Ca2+ entry inhibited the Ca2+ influx. Jasplakinolide, which reorganizes actin filaments into a tight cortical layer adjacent to the plasma membrane, prevented activation of store-dependent Ca2+ entry but did not modify this process after its activation. Vesicular transport inhibitor brefeldin A, which inactivates arfproteins, inhibited activation of store-dependent Ca2+ entry but did not alter this mechanism once being initiated. These data are compatible with the sectretion-like coupling model for store-dependent Ca2+ entry in macrophages based on a reversible trafficking and coupling of Ca2+ store with the plasma membrane.
Kurilova
L S
LS
Krutetskaia
Z I
ZI
Lebedev
O E
OE
D000818:Animals; D020126:Brefeldin A / Q000494:pharmacology*; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels; D047630:Depsipeptides / Q000494:pharmacology*; D017737:Macrophages, Peritoneal / Q000378:metabolism*; D051381:Rats; D053778:Thiazolidines / Q000494:pharmacology*
D019086:Bridged Bicyclo Compounds, Heterocyclic; D015220:Calcium Channels; D047630:Depsipeptides; D053778:Thiazolidines; C057531:jasplakinolide; D020126:Brefeldin A; C037068:latrunculin B; D002118:Calcium