Cloning and expression of SLC1OA4,a putative organic anion transport protein |
| |
Authors: | Patrick L Splinter Konstantinos N Lazaridis Paul A Dawson Nicholas F LaRusso |
| |
Affiliation: | 1. The Center for Basic Research in Digestive Disease,Division of Gastroenterology and Hepatology, Mayo Medical School, Clinic and Foundation, Rochester, Minnesota 55905,United States 2. Department of Internal Medicine-Gastroenterology, Wake Forest University School of Medicine, WinstonSalem, North Carolina 27157, United States |
| |
Abstract: | AIM:To determine if novel bile acid transporters may be expressed in human tissues.METHODS:SLC10A1 (NTCP) was used as a probe to search the NCBI database for homology to previously uncharacterized ESTs. The homology search identified an EST (termed SLC10A4) that shares sequence identity with SLC10A1 and SLC10A2 (ASBT). We performed Northern blot analysis and RT-PCR to determine the tissue distribution of SLC10A4. SLC10A4 was cloned in frame with an epitope tag and overexpressed in CHO cells to determine cellular localization and functional analysis of bile acid uptake.RESULTS:Northern analysis revealed that SLC 10A4 mRNA is ubiquitously expressed fn human tissues with the highest levels of mRNA expression in brain,placenta, and liver. In SLC10A4-transfected CHO cells,immunoblotting analysis and immunofluorescence staining demonstrated a 49-kDa protein that is expressed at the plasma membrane and intracellular compartments.Functional analysis of SLC10A4 showed no significant taurocholate uptake in the presence of sodium when compared to untransfected CHO cells.CONCLUSION:To date, we have shown that this protein has no capacity to transport taurocholate relative to SLC1041; however, given its ubiquitous tissue distribution, it may play a more active role in transporting other endogenous organic anions. |
| |
Keywords: | SLC10A4 Bile acid transport Biliary epithelium Taurocholate Plasma membrane |
本文献已被 万方数据 等数据库收录! |
|