Effects of Ala Substitution for Conserved Cys Residues in Mouse Ileal and Hepatic Na+-Dependent Bile Acid Transporters
| Autor: | Kimikazu Iwami, Kazumitsu Ueda, Yuki Munetaka, Tohru Saeki, Ryuhei Kanamoto |
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| Rok vydání: | 2007 |
| Předmět: |
Taurocholic Acid
inorganic chemicals endocrine system medicine.drug_class Mutant Mutation Missense Organic Anion Transporters Sodium-Dependent Biology Applied Microbiology and Biotechnology Biochemistry Analytical Chemistry Bile Acids and Salts Mice chemistry.chemical_compound Ileum medicine Animals Cysteine Site-directed mutagenesis Molecular Biology Conserved Sequence chemistry.chemical_classification SLC10A2 SLC10A1 Alanine Symporters Bile acid digestive oral and skin physiology Organic Chemistry General Medicine Taurocholic acid Amino acid Kinetics Amino Acid Substitution Liver chemistry biology.protein Biotechnology |
| Zdroj: | Bioscience, Biotechnology, and Biochemistry. 71:1865-1872 |
| ISSN: | 1347-6947 0916-8451 |
| Popis: | Although ileal and hepatic Na(+)-dependent bile acid transporters (SLC10A2 and SLC10A1 respectively) share structural similarities, the mutation of conserved amino acids often has distinct effects on them. We have identified two Cys residues in mouse Slc10a2 (Cys(51) and Cys(106)) the replacement of which by Ala remarkably reduces taurocholic acid (TCA) transport. Although Cys(51) is conserved in Slc10a1 as Cys(44), Ala substitution gave no apparent difference in TCA uptake. Here, we further analyzed the kinetics of TCA uptake and cell surface localization of these mutants. The C51A and C106A mutants of Slc10a2 showed significantly reduced TCA uptake, while no apparent difference in TCA uptake was observed for the Slc10a1-C44A mutant. The K(m) values for TCA uptake by these mutants were comparable, suggesting that these residues are not involved in the interaction with TCA. |
| Databáze: | OpenAIRE |
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