Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
16
pubmed:dateCreated
1998-5-21
pubmed:databankReference
pubmed:abstractText
Canalicular secretion of bile salts is a vital function of the vertebrate liver, yet the molecular identity of the involved ATP-dependent carrier protein has not been elucidated. We cloned the full-length cDNA of the sister of P-glycoprotein (spgp; Mr approximately 160,000) of rat liver and demonstrated that it functions as an ATP-dependent bile salt transporter in cRNA injected Xenopus laevis oocytes and in vesicles isolated from transfected Sf9 cells. The latter demonstrated a 5-fold stimulation of ATP-dependent taurocholate transport as compared with controls. This spgp-mediated taurocholate transport was stimulated solely by ATP, was inhibited by vanadate, and exhibited saturability with increasing concentrations of taurocholate (Km approximately 5 microM). Furthermore, spgp-mediated transport rates of various bile salts followed the same order of magnitude as ATP-dependent transport in canalicular rat liver plasma membrane vesicles, i.e. taurochenodeoxycholate > tauroursodeoxycholate = taurocholate > glycocholate = cholate. Tissue distribution assessed by Northern blotting revealed predominant, if not exclusive, expression of spgp in the liver, where it was further localized to the canalicular microvilli and to subcanalicular vesicles of the hepatocytes by in situ immunofluorescence and immunogold labeling studies. These results indicate that the sister of P-glycoprotein is the major canalicular bile salt export pump of mammalian liver.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
17
pubmed:volume
273
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
10046-50
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:9545351-ATP-Binding Cassette Transporters, pubmed-meshheading:9545351-Adenosine Triphosphate, pubmed-meshheading:9545351-Amino Acid Sequence, pubmed-meshheading:9545351-Animals, pubmed-meshheading:9545351-Bile Acids and Salts, pubmed-meshheading:9545351-Bile Canaliculi, pubmed-meshheading:9545351-Cell Line, pubmed-meshheading:9545351-Cloning, Molecular, pubmed-meshheading:9545351-DNA Primers, pubmed-meshheading:9545351-Female, pubmed-meshheading:9545351-Kinetics, pubmed-meshheading:9545351-Liver, pubmed-meshheading:9545351-Molecular Sequence Data, pubmed-meshheading:9545351-Oocytes, pubmed-meshheading:9545351-Polymerase Chain Reaction, pubmed-meshheading:9545351-Rats, pubmed-meshheading:9545351-Recombinant Proteins, pubmed-meshheading:9545351-Spodoptera, pubmed-meshheading:9545351-Taurocholic Acid, pubmed-meshheading:9545351-Transfection, pubmed-meshheading:9545351-Xenopus laevis
pubmed:year
1998
pubmed:articleTitle
The sister of P-glycoprotein represents the canalicular bile salt export pump of mammalian liver.
pubmed:affiliation
Division of Clinical Pharmacology and Toxicology, Department of Medicine, University Hospital, CH-8091 Zurich, Switzerland.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't