Transport of Glutamate and Glutamine in the Light Leaf Spot Pathogen Pyrenopeziza brassicae

The kinetics of giutamic acid and glutamine uptake in the light leaf spot fungus, Pyrenopeziza brassicae, are biphasic. At low and high concentrations, giutamic acid and glutamine share a high-aiBnity and a low-affinity carrier, respectively, with K,nS of 4.0 and 4.4 ;IM for uptake of glutatnic acid and glutamine, respectively, by the high-affinity system, and K^s of 580 and 560 ^M for uptake of giutamic acid and glutamitie by the low-affinity system. The data suggest that giutamic acid and glutamine are taken up by a different system to that responsible for the uptake of omithine, arginine, lysine and asparagine, and may represent system IV described in Neurospora crassa for the uptake of acidic amino acids