title: Evidence for rat organic anion transporter 3 association with caveolin-1 in rat kidney.
abstract: The rat organic anion transporter 3 (rOAT3) has recently been identified as the third isoform of the OAT family. The mechanisms that regulate rOAT3's functions remain to be elucidated. rOAT3 contributes for moving a number of negatively charged organic compounds between cells and their extracellular milieu. Caveolin (Cav) also plays a role as a membrane transporter. To address the relationship of these two proteins, we investigated the protein-protein interaction between rOAT3 and Cav-1. The rOAT3 mRNA and protein expression were observed in the rat kidney, and the expressions of Cav-1 mRNA and protein were also detected in the kidney. Confocal microscopy of the immuno-cytochemistry experiments using primary cultured renal proximal tubular cells showed that rOAT3 and Cav-1 were co-localized at the plasma membrane. This finding was confirmed by Western blot analysis using isolated caveolae-enriched membrane fractions from the rat kidney and immuno-precipitation experimentation. When rOAT3's synthesized cRNA of rOAT3 along with the antisense oligo deoxynucleotide ofXenopusCav-1 were co-injected intoXenopusoocytes, the [(3)H] estrone sulfate uptake was significantly decreased. These findings suggest that rOAT3 and caveolin-1 share a cellular expression in the plasma membrane and Cav-1 up-regulates the organic anionic compound uptake via rOAT3 under normal physiological conditions.
authors.affiliation: Department of Pharmacology and Toxicology, Inha Research Institute for Medical Sciences, Incheon, Korea.
authors.forename: Jin-Oh
authors.initials: JO
authors.lastname: Kwak
authors.forename: Hyun-Woo
authors.initials: HW
authors.lastname: Kim
authors.forename: Joon Ho
authors.initials: JH
authors.lastname: Song
authors.forename: Moon-Jae
authors.initials: MJ
authors.lastname: Kim
authors.forename: Hyeon-Seon
authors.initials: HS
authors.lastname: Park
authors.forename: Dong-Keun
authors.initials: DK
authors.lastname: Hyun
authors.forename: Dong Soo
authors.initials: DS
authors.lastname: Kim
authors.forename: Seok Ho
authors.initials: SH
authors.lastname: Cha
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001693:Biological Transport, Active / Q000502:physiology; D015153:Blotting, Western; D051242:Caveolin 1; D022461:Caveolins / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D017931:DNA Primers; D004970:Estrone / Q000031:analogs & derivatives / Q000378:metabolism; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D017136:Ion Transport / Q000502:physiology; D007668:Kidney / Q000378:metabolism*; D018613:Microscopy, Confocal; D016376:Oligonucleotides, Antisense; D009865:Oocytes / Q000378:metabolism; D029362:Organic Anion Transporters, Sodium-Independent / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014316:Tritium; D014981:Xenopus; D029867:Xenopus Proteins
chemical_list: C495539:CAV1 protein, Xenopus; C495537:Cav1 protein, rat; D051242:Caveolin 1; D022461:Caveolins; D017931:DNA Primers; D016376:Oligonucleotides, Antisense; D029362:Organic Anion Transporters, Sodium-Independent; D012333:RNA, Messenger; D029867:Xenopus Proteins; C114338:organic anion transport protein 3; D014316:Tritium; D004970:Estrone; C017296:estrone sulfate