The products of YCF1 and YLL015w (BPT1) cooperate for the ATP‐dependent vacuolar transport of unconjugated bilirubin in Saccharomyces cerevisiae

• Published in: Yeast (Chichester, England) England), 2000-04, Vol.16 (6), p.561-571
• Main Authors: Petrovic, Sinisa, Pascolo, Lorella, Gallo, Romina, Cupelli, Felicia, Ostrow, J. Donald, Goffeau, André, Tiribelli, Claudio, Bruschi, Carlo V.
• Format: Article
• Language: English
• Subjects: ABC transporters; Adenosine Triphosphate - analogs & derivatives; Adenosine Triphosphate - pharmacology; Amino Acid Sequence; ATP-Binding Cassette Transporters - genetics; ATP-Binding Cassette Transporters - metabolism; bilirubin; Bilirubin - metabolism; Biological Transport - drug effects; Calcium-Transporting ATPases - antagonists & inhibitors; Fungal Proteins - genetics; Fungal Proteins - metabolism; Gene Deletion; Kinetics; Molecular Sequence Data; MRPs; Mutation; Saccharomyces cerevisiae; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae Proteins; Sequence Homology, Amino Acid; Sodium-Potassium-Exchanging ATPase - antagonists & inhibitors; Time Factors; Vacuoles - metabolism; Vanadates - pharmacology; YCF1; YCR1 gene; yeast; YLLO15w gene
• ISSN: 0749-503X; 1097-0061
• DOI: 10.1002/(SICI)1097-0061(200004)16:6<561::AID-YEA551>3.0.CO;2-L

Since bilirubin‐like pigments are present in the environment as degradation products of heme‐containing proteins, yeast could have developed a detoxifying system to transport these compounds into their vacuoles. Vacuoles from Saccharomyces cerevisiae showed an ATP‐dependent, saturative transport of unconjugated bilirubin (UCB) that was reduced by 60% and 40% in YCF1 and YLL015w‐deleted cells, respectively; the double deletant showed no UCB uptake. Conversely, the transport of bile acids (taurocholate) was comparable in wild and deleted stains. These data identify YCF1 and YLL015w, named BPT1 (Bile Pigment Transporter), as the genes responsible for ATP‐dependent UCB transport in yeast. Since YCF1 and YLL015w are rather homologous with multidrug resistant proteins (MRPs), they also suggest the involvement of this class of transporters in the ATP‐dependent transport of unconjugated bilirubin. Copyright © 2000 John Wiley & Sons, Ltd.