Intracellular water volume and internal pH of Streptomyces antibioticus spores |
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Authors: | Luis M. Quiró s,José A. Salas |
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Affiliation: | National Institute of Cholera and Enteric Diseases, P-33 C.I.T. Road, Scheme XM, Beliaghata P.O. Box 177, Calcutta 700010, India |
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Abstract: | Abstract 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 Ca2+-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. |
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Keywords: | Escherichia coli Intracellular calcium ion concentration Actin HeLa cell |
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