| http://purl.uniprot.org/citations/23132865 | http://www.w3.org/1999/02/22-rdf-syntax-ns#type | http://purl.uniprot.org/core/Journal_Citation |
| http://purl.uniprot.org/citations/23132865 | http://www.w3.org/1999/02/22-rdf-syntax-ns#type | http://purl.uniprot.org/core/Journal_Citation |
| http://purl.uniprot.org/citations/23132865 | http://www.w3.org/2000/01/rdf-schema#comment | "The high-affinity choline transporter CHT1 mediates choline uptake essential for acetylcholine synthesis in cholinergic nerve terminals. CHT1 belongs to the Na(+)/glucose cotransporter family (SLC5), which is postulated to have a common 13-transmembrane domain core; however, no direct experimental evidence for CHT1 transmembrane topology has yet been reported. We examined the transmembrane topology of human CHT1 using cysteine-scanning analysis. Single cysteine residues were introduced into the putative extra- and intracellular loops and probed for external accessibility for labeling with a membrane-impermeable, sulfhydryl-specific biotinylating reagent in intact cells expressing these mutants. The results provide experimental evidence for a topological model of a 13-transmembrane domain protein with an extracellular amino terminus and an intracellular carboxyl terminus. We also constructed a three-dimensional homology model of CHT1 based on the crystal structure of the bacterial Na(+)/galactose cotransporter, which supports our conclusion of CHT1 transmembrane topology. Furthermore, we examined whether CHT1 exists as a monomer or oligomer. Chemical cross-linking induces the formation of a higher molecular weight form of CHT1 on the cell surface in HEK293 cells. Two different epitope-tagged CHT1 proteins expressed in the same cells can be co-immunoprecipitated. Moreover, co-expression of an inactive mutant I89A with the wild type induces a dominant-negative effect on the overall choline uptake activity. These results indicate that CHT1 forms a homo-oligomer on the cell surface in cultured cells."xsd:string |
| http://purl.uniprot.org/citations/23132865 | http://purl.org/dc/terms/identifier | "doi:10.1074/jbc.m112.405027"xsd:string |
| http://purl.uniprot.org/citations/23132865 | http://purl.org/dc/terms/identifier | "doi:10.1074/jbc.m112.405027"xsd:string |
| http://purl.uniprot.org/citations/23132865 | http://purl.uniprot.org/core/author | "Hayashi K."xsd:string |
| http://purl.uniprot.org/citations/23132865 | http://purl.uniprot.org/core/author | "Hayashi K."xsd:string |
| http://purl.uniprot.org/citations/23132865 | http://purl.uniprot.org/core/author | "Ogawa H."xsd:string |
| http://purl.uniprot.org/citations/23132865 | http://purl.uniprot.org/core/author | "Ogawa H."xsd:string |
| http://purl.uniprot.org/citations/23132865 | http://purl.uniprot.org/core/author | "Nishikawa S."xsd:string |
| http://purl.uniprot.org/citations/23132865 | http://purl.uniprot.org/core/author | "Nishikawa S."xsd:string |
| http://purl.uniprot.org/citations/23132865 | http://purl.uniprot.org/core/author | "Satou M."xsd:string |
| http://purl.uniprot.org/citations/23132865 | http://purl.uniprot.org/core/author | "Satou M."xsd:string |
| http://purl.uniprot.org/citations/23132865 | http://purl.uniprot.org/core/author | "Yamada H."xsd:string |
| http://purl.uniprot.org/citations/23132865 | http://purl.uniprot.org/core/author | "Yamada H."xsd:string |
| http://purl.uniprot.org/citations/23132865 | http://purl.uniprot.org/core/author | "Kubo Y."xsd:string |
| http://purl.uniprot.org/citations/23132865 | http://purl.uniprot.org/core/author | "Kubo Y."xsd:string |
| http://purl.uniprot.org/citations/23132865 | http://purl.uniprot.org/core/author | "Haga T."xsd:string |
| http://purl.uniprot.org/citations/23132865 | http://purl.uniprot.org/core/author | "Haga T."xsd:string |
| http://purl.uniprot.org/citations/23132865 | http://purl.uniprot.org/core/author | "Okuda T."xsd:string |
| http://purl.uniprot.org/citations/23132865 | http://purl.uniprot.org/core/author | "Okuda T."xsd:string |
| http://purl.uniprot.org/citations/23132865 | http://purl.uniprot.org/core/author | "Osawa C."xsd:string |
| http://purl.uniprot.org/citations/23132865 | http://purl.uniprot.org/core/author | "Osawa C."xsd:string |
| http://purl.uniprot.org/citations/23132865 | http://purl.uniprot.org/core/author | "Ushio T."xsd:string |
| http://purl.uniprot.org/citations/23132865 | http://purl.uniprot.org/core/author | "Ushio T."xsd:string |