Chemotaxis in Dictyostelium discoideum: effect of concanavalin A on chemoattractant mediated cyclic gmp accumulation anlight scattering decrease.
In cells of the cellular slime mold Dictyostelium discoideum concanavalin A (Con A), at a concentration of 100 microgram per ml, inhibits folic acid and cyclic AMP induced decrease in light scattering. Con A has no effect on folic acid mediated cyclic GMP accumulation and increases cyclic AMP mediated cyclic GMP accumulation two-fold. At a lower Con A concentration, 10 microgram per ml, changes in light scattering induced by folic acid are normal and cyclic AMP induces a monophasic instead of a biphasic response. The stimulatory effect of Con A on cyclic AMP mediated cyclic GMP accumulation is still observable at 10 microgram Con A per ml. When cells are repeatedly stimulated with cyclic AMP, a decrease in light scattering without being accompanied by changes in cyclic GMP concentration is observed. Based on these results a model for chemotaxis is proposed.
D002633:Chemotaxis / Q000187:drug effects*; D003208:Concanavalin A / Q000494:pharmacology*; D000242:Cyclic AMP / Q000494:pharmacology; D006152:Cyclic GMP / Q000378:metabolism*; D004023:Dictyostelium / Q000187:drug effects* / Q000502:physiology; D005492:Folic Acid / Q000494:pharmacology; D008027:Light; D009235:Myxomycetes / Q000187:drug effects*; D012542:Scattering, Radiation
D003208:Concanavalin A; D005492:Folic Acid; D000242:Cyclic AMP; D006152:Cyclic GMP