GABA uptake in a Saccharomyces cerevisiae strain.

The aim of this work was to characterize the 4-aminobutyric acid (GABA) transport in the Saccharomyces cerevisiae D27 strain, followed by the study of the relationship between 5-aminolevulinic acid (ALA) and GABA transport systems. It was found that the general amino acid permease (GAP) is not active in D27 strain, suggesting that GABA incorporation should be mediated by PUT4 and UGA4 permeases. However, after kinetic studies only one system was detected. It was also shown that GABA uptake is competitively inhibited by ALA. GABA incorporation is regulated by the carbon source but not by the nitrogen source. When cells were grown in the presence of GABA, its entrance was very low.