Linked Life Data

19760661

Source:http://linkedlifedata.com/resource/pubmed/id/19760661

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2009-11-2
pubmed:abstractText
The liver-specific organic anion transporting polypeptides OATP1B1 and OATP1B3 are highly homologous and share numerous substrates. However, at low concentrations OATP1B1 shows substrate selectivity for estrone-3-sulfate. In this study, we investigated the molecular mechanism for this substrate selectivity of OATP1B1 by constructing OATP1B1/1B3 chimeric transporters and by site-directed mutagenesis. Functional studies of chimeras showed that transmembrane domain 10 is critical for the function of OATP1B1. We further identified four amino acid residues, namely L545, F546, L550, and S554 in TM10, whose simultaneous mutation caused almost complete loss of OATP1B1-mediated estrone-3-sulfate transport. Comparison of the kinetics of estrone-3-sulfate transport confirmed a biphasic pattern for OATP1B1, but showed a monophasic pattern for the quadruple mutant L545S/F546L/L550T/S554T. This mutant also showed reduced transport for other OATP1B1 substrates such as bromosulfophthalein and [D-penicillamine(2,5)]enkephalin. Helical wheel analysis and molecular modeling suggest that L545 is facing the substrate translocation pathway, whereas F546, L550, and S554 are located inside the protein. These results indicate that L545 might contribute to OATP1B1 function by interacting with substrates, whereas F546, L550, and S554 seem important for protein structure. In conclusion, our results show that TM10 is critical for the function of OATP1B1.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
1469-896X
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
18
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2298-306
pubmed:dateRevised
2010-11-2
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Role of transmembrane domain 10 for the function of organic anion transporting polypeptide 1B1.
pubmed:affiliation
Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural