Characterization of Avt1p as a vacuolar proton/amino acid antiporter in Saccharomyces cerevisiae.
Several genes for vacuolar amino acid transport were reported in Saccharomyces cerevisiae, but have not well been investigated. We characterized AVT1, a member of the AVT vacuolar transporter family, which is reported to be involved in lifespan of yeast. ATP-dependent uptake of isoleucine and histidine by the vacuolar vesicles of an AVT exporter mutant was lost by introducing avt1∆ mutation. Uptake activity was inhibited by the V-ATPase inhibitor: concanamycin A and a protonophore. Isoleucine uptake was inhibited by various neutral amino acids and histidine, but not by γ-aminobutyric acid, glutamate, and aspartate. V-ATPase-dependent acidification of the vesicles was declined by the addition of isoleucine or histidine, depending upon Avt1p. Taken together with the data of the amino acid contents of vacuolar fractions in cells, the results suggested that Avt1p is a proton/amino acid antiporter important for vacuolar compartmentalization of various amino acids.
a Laboratory of Molecular Physiology and Genetics, Faculty of Agriculture , Ehime University , Matsuyama , Japan.
Junichi
J
Tone
Ayumi
A
Yoshimura
Kunio
K
Manabe
Nami
N
Murao
Takayuki
T
Sekito
Miyuki
M
Kawano-Kawada
Yoshimi
Y
Kakinuma
D026905:Amino Acid Transport Systems / Q000235:genetics / Q000378:metabolism*; D021542:Amino Acids, Neutral / Q000378:metabolism*; D017920:Antiporters / Q000235:genetics / Q000378:metabolism*; D001224:Aspartic Acid / Q000378:metabolism; D001692:Biological Transport; D018698:Glutamic Acid / Q000378:metabolism; D006639:Histidine / Q000378:metabolism; D007425:Intracellular Membranes / Q000378:metabolism; D007532:Isoleucine / Q000378:metabolism; D011522:Protons; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D014617:Vacuoles / Q000378:metabolism*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D026905:Amino Acid Transport Systems; D021542:Amino Acids, Neutral; D017920:Antiporters; C000607320:Avt1 protein, S cerevisiae; D011522:Protons; D029701:Saccharomyces cerevisiae Proteins; D007532:Isoleucine; D001224:Aspartic Acid; D018698:Glutamic Acid; D006639:Histidine; D005680:gamma-Aminobutyric Acid
Saccharomyces cerevisiae; amino acid transporter; vacuole