Cloning and expression of the UGA4 gene coding for the inducible GABA-specific transport protein of Saccharomyces cerevisiae.
Transport of 4-aminobutyric acid (GABA) in Saccharomyces cerevisiae is mediated by three transport systems: the general amino acid permease (GAP1 gene), the proline permease (PUT4 gene), and a specific GABA permease (UGA4 gene) which is induced in the presence of GABA. The UGA4 gene encoding the inducible GABA-specific transporter was cloned and sequenced and its expression analyzed. The predicted amino acid sequence shows that UGA4 encodes a 62 kDa protein having 9-12 putative membrane-spanning regions. The predicted UGA4 protein shares significant sequence similarity with the yeast choline transporter (CTR gene), exhibiting but limited similarity to the previously reported GABA transporters, i.e. the yeast GAP1 and PUT4 permeases and the rat brain GAT-1 transporter. Induction of UGA4 in the presence of GABA is exerted at the level of UGA4 mRNA accumulation, most probably at the level of transcription itself. This induction is conferred by the 5' flanking region and requires the integrity of two positive regulatory proteins, the inducer-specific factor UGA3 and the pleiotropic factor UGA35/DURL/DAL81. In the absence of the pleiotropic UGA43/DAL80 repressor, UGA4 is constitutively expressed at high level.
André
B
B
Laboratoire de Physiologie Cellulaire et de Génétique des Levures, Université Libre de Bruxelles, Belgium.
Hein
C
C
Grenson
M
M
Jauniaux
J C
JC
D000595:Amino Acid Sequence; D001483:Base Sequence; D002352:Carrier Proteins / Q000096:biosynthesis / Q000235:genetics*; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D029968:Escherichia coli Proteins; D050485:GABA Plasma Membrane Transport Proteins; D005816:Genetic Complementation Test; D007763:Lac Operon / Q000235:genetics; D008565:Membrane Proteins / Q000096:biosynthesis / Q000235:genetics*; D026901:Membrane Transport Proteins; D008969:Molecular Sequence Data; D027361:Organic Anion Transporters; D011487:Protein Conformation; D012333:RNA, Messenger / Q000032:analysis; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D002352:Carrier Proteins; D029968:Escherichia coli Proteins; D050485:GABA Plasma Membrane Transport Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D027361:Organic Anion Transporters; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; C493415:Slc6a1 protein, rat; C513599:UGA4 protein, S cerevisiae; C065637:choline transporter; C513601:gabP protein, E coli; D005680:gamma-Aminobutyric Acid