Mechanism of enhanced fusion capacity of mouse red cells infected with Plasmodium berghei.
Plasmodium berghei-infected mouse red cells have enhanced fusion capacity as triggered by addition of poly(ethylene glycol) in the presence of Ca2+. The uptake of Ca2+ in P. berghei-infected cells is greater than in normal cells, and the difference in Ca2+ uptake was found to be enhanced in the presence of poly(ethylene glycol). Fusion of normal and P. berghei-infected red cells by poly(ethylene glycol) was significantly inhibited by N-tosyl-L-lysylchloromethyl ketone and phenylmethylsulphonyl fluoride. In addition, ethyleneglycolbis(aminoethylether)tetra-acetate, N-ethylmaleimide, iodoacetamide, cystamine and tetrathionate also prevented fusion in both systems. In contrast, N-tosyl-L-phenylalanylchloromethyl ketone and N-tosyl-L-arginine methyl ester did not inhibit cell fusion. The latter enhanced fusion of infected cells but was without effect on normal cells. These results indicate that a Ca2+-activated thiol proteinase may be involved in membrane fusion in malaria-infected as well as in normal red cells. However, differences in the effect of proteinase inhibitors and substrate on fusion and Ca2+ entry show that the processes leading to fusion may not be identical.
D000818:Animals; D002118:Calcium / Q000097:blood; D002459:Cell Fusion / Q000187:drug effects; D002478:Cells, Cultured; D004533:Egtazic Acid / Q000494:pharmacology; D004912:Erythrocytes / Q000378:metabolism / Q000502:physiology*; D008288:Malaria / Q000097:blood*; D051379:Mice; D010664:Phenylmethylsulfonyl Fluoride / Q000494:pharmacology; D010962:Plasmodium berghei; D011092:Polyethylene Glycols / Q000494:pharmacology; D013438:Sulfhydryl Compounds / Q000494:pharmacology; D014107:Tosyllysine Chloromethyl Ketone / Q000494:pharmacology
D013438:Sulfhydryl Compounds; D014107:Tosyllysine Chloromethyl Ketone; D011092:Polyethylene Glycols; D004533:Egtazic Acid; D010664:Phenylmethylsulfonyl Fluoride; D002118:Calcium