Comparison of cytosolic levels of calcium and G actin in diffuse and localised adherent Escherichia coli-infected HeLa cells.
In the present study we compared the intracellular level of free calcium ([Ca2+]i) and monomeric (G)/total (G+F) actin ratio in HeLa cells infected with diffuse (DAEC) and localised adherent Escherichia coli (LAEC). The level of [Ca2+]i was increased in both DAEC- and LAEC-infected HeLa cells. However, studies with EGTA- and dantrolene-treated cells and also suspension of cells in Ca(2+)-free buffer suggested that the rise of [Ca2+]i in DAEC-infected cells was due to the influx of Ca2+ from extracellular medium, whereas Ca2+ mobilisation from the intracellular stores was responsible for the enhancement of [Ca2+]i in LAEC-infected cells. It was also evident that the infection of HeLa cells with DAEC and LAEC caused alteration of G/G+F actin ratio as compared to that of control cells. The ratio was much lower in LAEC-infected cells than that of DAEC-infected ones. Moreover, cytochalasin B inhibited both DAEC and LAEC invasion to HeLa cells, suggesting further the role of microfilaments in the invasion process.
Karmaker
S
S
National Institute of Cholera and Enteric Diseases, Calcutta, India.
Chaudhuri
A G
AG
Ganguly
U
U
D000199:Actins / Q000378:metabolism*; D001422:Bacterial Adhesion; D002118:Calcium / Q000378:metabolism*; D003571:Cytochalasin B / Q000494:pharmacology; D003600:Cytosol / Q000378:metabolism; D004926:Escherichia coli / Q000166:cytology / Q000472:pathogenicity*; D006367:HeLa Cells; D006801:Humans; D017136:Ion Transport
D000199:Actins; D003571:Cytochalasin B; D002118:Calcium