Expression of the choroid plexus sodium-nucleoside cotransporter (N3) in Xenopus laevis oocytes.
In this study, we determined the expression of the Na(+)-nucleoside cotransporter (N3) in Xenopus laevis oocytes injected with poly(A)+ RNA isolated from rabbit choroid plexus. The Na(+)-dependent thymidine uptake in poly(A)+ RNA-injected oocytes (maximum 4-5 days after injection) increased proportionally with the injected dose of poly(A)+ RNA. Uptake was enhanced 4- to 5-fold in oocytes injected with 40 ng poly (A)+ RNA in comparison to water-injected oocytes. Consistent with the N3 Na(+)-nucleoside cotransporter, Na(+)-dependent thymidine uptake in poly(A)+ RNA-injected oocytes was inhibited significantly by both purine and pyrimidine nucleosides, but not by dideoxycytidine, a nucleoside analog modified on the ribose ring. These data suggest for the first time that the N3 Na(+)-nucleoside cotransporter in rabbit choroid plexus can be expressed in X. laevis oocytes.
Wu
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School of Pharmacy, University of California, San Francisco 94143.
Giacomini
K M
KM
D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D002831:Choroid Plexus / Q000378:metabolism*; D015870:Gene Expression; D009705:Nucleosides / Q000378:metabolism; D009865:Oocytes / Q000378:metabolism*; D011061:Poly A / Q000008:administration & dosage / Q000494:pharmacology*; D012313:RNA / Q000008:administration & dosage / Q000494:pharmacology*; D012333:RNA, Messenger; D011817:Rabbits; D012964:Sodium / Q000378:metabolism; D027981:Symporters; D013936:Thymidine / Q000378:metabolism; D014982:Xenopus laevis
D002352:Carrier Proteins; D009705:Nucleosides; D012333:RNA, Messenger; D027981:Symporters; C073034:sodium-nucleoside cotransporter; D011061:Poly A; D012313:RNA; D012964:Sodium; D013936:Thymidine