Effect of monensin on myoblast fusion.
Monensin, at a concentration of 0.5-10 microM, completely (100%) and reversibly inhibits fusion of embryonic chick myoblasts in vitro. At the same time, monensin administration leads to a marked accumulation of glycopeptides inside the cells and a decrease of those secreted into the medium. Chromatography of the intracellularly retained glycopeptides on Con A-Sepharose shows that the increase is most pronounced in the high-mannose fraction. Mild proteolysis of cells labeled with [2-3H]mannose releases less radioactivity from the surface of monensin-treated than from control cells, although the amount of total radioactivity is almost four times higher than in the control cells. Since it has now been established that monensin interferes with the intracellular transport of newly synthesized glycoproteins it is assumed that its inhibitory effect is the result of the inability of glycoprotein(s) essential for myoblast fusion to reach the cell surface.
D000643:Ammonium Chloride / Q000494:pharmacology; D000818:Animals; D002459:Cell Fusion; D002642:Chick Embryo; D002738:Chloroquine / Q000494:pharmacology; D005663:Furans / Q000494:pharmacology*; D008358:Mannose / Q000378:metabolism; D008985:Monensin / Q000494:pharmacology*; D009132:Muscles / Q000166:cytology* / Q000187:drug effects; D011402:Pronase / Q000378:metabolism
D005663:Furans; D000643:Ammonium Chloride; D002738:Chloroquine; D008985:Monensin; D011402:Pronase; D008358:Mannose