The role of extracellular calcium ions in HVJ (Sendai virus)-induced cell fusion.
The biochemical and biophysical roles of extracellular calcium ions in HVJ (Sendai virus)-induced cell fusion were studied. (1) Various kinds of cell, such as Ehrlich ascites tumor cells, mouse melanoma cells (B16-CW1 cells) and human epidermoid carcinoma cells (KB cells), could fuse in Ca2+-free medium containing a cheletor, glycoletherdiaminetetraacetic acid, in the same way as in Ca2+-containing medium. (2) The ATP content in Ehrlich ascites tumor cells decreased rapidly when the cells were treated with the virus in Ca2+-free medium but not in Ca2+-containing medium. (3) Intracellular adenine nucleotides leaked out into the reaction medium when the cells were treated with the virus in Ca2+-free medium but not in Ca2+-containing medium. (4) On addition of the virus, O2 consumption of Ehrlich ascites tumor cells decreased in Ca2+-free medium, but not in Ca2+-containing medium. (5) HVJ (Sendai virus) did not affect production of lactate by Ehrlich ascites tumor cells in both Ca2+-free medium and Ca2+-containing medium. These observations suggest that the role of extracellular Ca2+ in virus-induced cell fusion is to maintain the ATP and other intracellular metabolite contents at normal levels instead of triggering the fusion reaction itself.
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002286:Carcinoma, Ehrlich Tumor / Q000378:metabolism; D002294:Carcinoma, Squamous Cell; D002459:Cell Fusion / Q000187:drug effects*; D002460:Cell Line; D002472:Cell Transformation, Viral / Q000187:drug effects*; D006801:Humans; D007700:Kinetics; D008545:Melanoma; D051379:Mice; D010222:Parainfluenza Virus 1, Human / Q000378:metabolism*
D000255:Adenosine Triphosphate; D002118:Calcium