The products of YCF1 and YLL015w (BPT1) cooperate for the ATP-dependent vacuolar transport of unconjugated bilirubin in Saccharomyces cerevisiae.
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.
Petrovic
S
S
Centro Studi Fegato (CSF), Department of BBCM, University of Trieste, Trieste, Italy.
Pascolo
L
L
Gallo
R
R
Cupelli
F
F
Ostrow
J D
JD
Goffeau
A
A
Tiribelli
C
C
Bruschi
C V
CV
D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology*; D000595:Amino Acid Sequence; D001663:Bilirubin / Q000378:metabolism*; D001692:Biological Transport / Q000187:drug effects; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D007700:Kinetics; D008969:Molecular Sequence Data; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors; D013997:Time Factors; D014617:Vacuoles / Q000378:metabolism*; D014638:Vanadates / Q000494:pharmacology
D018528:ATP-Binding Cassette Transporters; D005656:Fungal Proteins; D029701:Saccharomyces cerevisiae Proteins; C089179:YCF1 protein, S cerevisiae; C005147:5'-adenylyl (beta,gamma-methylene)diphosphonate; D014638:Vanadates; D000255:Adenosine Triphosphate; D000252:Calcium-Transporting ATPases; D000254:Sodium-Potassium-Exchanging ATPase; C002630:alpha,beta-methyleneadenosine 5'-triphosphate; D001663:Bilirubin