Substrate specificities of active transport systems for amino acids in vacuolar-membrane vesicles of Saccharomyces cerevisiae. Evidence of seven independent proton/amino acid antiport systems.
The substrate specificities of the amino acid transport systems of vacuoles of the yeast, Saccharomyces cerevisiae, were investigated using purified vacuolar-membrane vesicles (Ohsumi, Y., and Anraku, Y. (1981) J. Biol. Chem. 256, 2079-2082). Ten amino acids: arginine, lysine, histidine, phenylalanine, tryptophan, tyrosine, glutamine, asparagine, isoleucine, and leucine, were taken up actively into the vesicles. Kinetic studies indicated the presence of seven independent H+/amino acid antiport systems with narrow substrate specificity, which were all driven by a proton motive force established by ATP hydrolysis. The Kt and Vmax values, and the specific inhibitors for the arginine, arginine-lysine, histidine, phenylalanine-tryptophan, tyrosine, glutamine-asparagine, and isoleucine-leucine transport systems were determined.
D000596:Amino Acids / Q000378:metabolism*; D001693:Biological Transport, Active; D006639:Histidine / Q000494:pharmacology; D008433:Mathematics; D006180:Proton-Translocating ATPases / Q000378:metabolism; D011522:Protons; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D013379:Substrate Specificity
D000596:Amino Acids; D011522:Protons; D006639:Histidine; D006180:Proton-Translocating ATPases