title: Retinal-specific ATP-binding cassette transporter (ABCR/ABCA4) is expressed at the choroid plexus in rat brain.
abstract: ATP-binding cassette (ABC) transporter A4 is a member of the ABC transporter subfamily A which has been reported to be exclusively expressed in the retina. In contrast, a previous report has suggested a possible relationship between ABCA4 and CNS function. The purpose of the present study was to investigate the localization of ABCA4 mRNA and protein in rat brain. In situ hybridization analysis revealed that ABCA4 mRNA was localized in the lateral ventricles. RT-PCR analysis detected ABCA4 mRNA in isolated rat choroid plexus and conditionally immortalized rat choroid plexus epithelial cells (TR-CSFB). Furthermore, ABCA4 protein was also detected in the isolated rat choroid plexus at about 250 kDa by western blot analysis, and its apparent molecular size was reduced by N-glycosidase F treatment. These results suggest that glycosylated ABCA4 protein is expressed in rat choroid plexus epithelial cells. ABCA4 may play a role in the function of the blood-cerebrospinal fluid barrier and affect CSF conditions.
authors.affiliation: Department of Molecular Biopharmacy and Genetics, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan.
authors.forename: Jiraganya
authors.initials: J
authors.lastname: Bhongsatiern
authors.forename: Sumio
authors.initials: S
authors.lastname: Ohtsuki
authors.forename: Masanori
authors.initials: M
authors.lastname: Tachikawa
authors.forename: Satoko
authors.initials: S
authors.lastname: Hori
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Terasaki
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D015153:Blotting, Western / Q000379:methods; D001921:Brain / Q000033:anatomy & histology / Q000187:drug effects / Q000378:metabolism*; D002460:Cell Line; D002831:Choroid Plexus / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism; D015870:Gene Expression / Q000502:physiology*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D006026:Glycoside Hydrolases / Q000494:pharmacology; D006801:Humans; D017403:In Situ Hybridization / Q000379:methods; D008297:Male; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012160:Retina / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods
chemical_list: C056475:ABCA4 protein, human; D018528:ATP-Binding Cassette Transporters; C512840:Abca4 protein, rat; D012333:RNA, Messenger; D006026:Glycoside Hydrolases