4 aminobutyric acid 4 Aminolevulinic Acid 4 GABA Plasma Membrane Transport Proteins 4 Organic Anion Transporters 4 Saccharomyces cerevisiae 4 Saccharomyces cerevisiae Proteins 4 UGA4 gene 4 aminolevulinic acid 4 article 4 gene expression 4 nonhuman 4 Ambient pH 2 Amino Acid Transport Systems 2 Binding Sites 2 Carrier Proteins 2 Gene Expression Regulation, Fungal 2 Gene expression 2 Hydrogen-Ion Concentration 2 Lac Operon 2 Membrane Proteins 2 Promoter Regions (Genetics) 2 Sensor systems 2 Transcriptional regulation 2 acid 2 acidity 2 amino acid 2 bacterial enzyme 2 beta galactosidase 2 beta-Galactosidase 2 binding site 2