Contribution of intracellular calcium stores to an increase in cytosolic calcium concentration induced by Mannheimia haemolytica leukotoxin.

TitleContribution of intracellular calcium stores to an increase in cytosolic calcium concentration induced by Mannheimia haemolytica leukotoxin.
Publication TypeJournal Article
Year of Publication2003
AuthorsCudd L, Clarke CR, Clinkenbeard K
JournalFEMS microbiology letters
Volume225
Issue1
Pagination23-7
Date Published2003 Aug 8
ISSN0378-1097
KeywordsAnimals, Calcium Signaling, Cattle, Cytosol, Exotoxins, Inositol 1,4,5-Trisphosphate, Intracellular Fluid, Lanthanum, Macrocyclic Compounds, Magnesium Chloride, Mannheimia haemolytica, Neutrophils, Oxazoles, Ryanodine Receptor Calcium Release Channel, Thapsigargin
Abstract

The contribution of intracellular calcium stores to Mannheimia haemolytica leukotoxin (LKT)-induced increase in cytosolic calcium concentration was studied by pharmacologically inhibiting transport of calcium across the plasma and endoplasmic reticulum membranes of bovine neutrophils exposed to LKT. Active intracellular storage of calcium by sarcoplasmic/endoplasmic reticulum calcium ATPase, influx of extracellular calcium across the plasma membrane, and release of stored calcium via inositol triphosphate receptors and ryanodine-sensitive calcium channels were inhibited using thapsigargin, lanthanum chloride, xestospongin C, and magnesium chloride, respectively. Pre-incubation with thapsigargin attenuated the increase in cytosolic calcium concentration produced by LKT, thus confirming the involvement of intracellular calcium stores. Inhibitory effects of lanthanum chloride, xestospongin C, and magnesium chloride indicated that the increase in cytosolic calcium concentration induced by LKT resulted from both influx of calcium across the plasma membrane and release of calcium from intracellular stores.

Alternate JournalFEMS Microbiol. Lett.