|Name:||solute carrier family 28 (sodium-coupled nucleoside transporter), member 3|
|PubMed (11032837):|| Ritzel MW, Ng AM, Yao SY, Graham K, Loewen SK, Smith KM, Ritzel RG, MowlesDA, Carpenter P, Chen XZ, Karpinski E, Hyde RJ, Baldwin SA, Cass CE, Young JD. Molecular identification and characterization of novel human and mouseconcentrative Na+-nucleoside cotransporter proteins (hCNT3 and mCNT3) broadlyselective for purine and pyrimidine nucleosides (system cib).J Biol Chem. 2001 Jan 26;276(4):2914-27. Epub 2000 Oct 13. PMID: 11032837 [PubMed - indexed for MEDLINE]|
The human concentrative (Na(+)-linked) plasma membrane transport proteins hCNT1 and hCNT2 are selective for pyrimidine nucleosides (system cit) and purine nucleosides (system cif), respectively. Both have homologs in other mammalian species and belong to a gene family (CNT) that also includes hfCNT, a newly identified broad specificity pyrimidine and purine Na(+)-nucleoside symporter (system cib) from the ancient marine vertebrate, the Pacific hagfish (Eptatretus stouti). We now report the cDNA cloning and characterization of cib homologs of hfCNT from human mammary gland, differentiated human myeloid HL-60 cells, and mouse liver. The 691- and 703-residue human and mouse proteins, designated hCNT3 and mCNT3, respectively, were 79% identical in amino acid sequence and contained 13 putative transmembrane helices. hCNT3 was 48, 47, and 57% identical to hCNT1, hCNT2, and hfCNT, respectively. When produced in Xenopus oocytes, both proteins exhibited Na(+)-dependent cib-type functional activities. hCNT3 was electrogenic, and a sigmoidal dependence of uridine influx on Na(+) concentration indicated a Na(+):uridine coupling ratio of at least 2:1 for both hCNT3 and mCNT3 (cf 1:1 for hCNT1/2). Phorbol myristate acetate-induced differentiation of HL-60 cells led to the parallel appearance of cib-type activity and hCNT3 mRNA. Tissues containing hCNT3 transcripts included pancreas, bone marrow, trachea, mammary gland, liver, prostate, and regions of intestine, brain, and heart. The hCNT3 gene mapped to chromosome 9q22.2 and included an upstream phorbol myristate acetate response element.
>sp|Q9HAS3|S28A3_HUMAN Solute carrier family 28 member 3 OS=Homo sapiens GN=SLC28A3 PE=1 SV=1 MELRSTAAPRAEGYSNVGFQNEENFLENENTSGNNSIRSRAVQSREHTNTKQDEEQVTVEQDSPRNREHMEDDDEEMQQK GCLERRYDTVCGFCRKHKTTLRHIIWGILLAGYLVMVISACVLNFHRALPLFVITVAAIFFVVWDHLMAKYEHRIDEMLS PGRRLLNSHWFWLKWVIWSSLVLAVIFWLAFDTAKLGQQQLVSFGGLIMYIVLLFLFSKYPTRVYWRPVLWGIGLQFLLG LLILRTDPGFIAFDWLGRQVQTFLEYTDAGASFVFGEKYKDHFFAFKVLPIVVFFSTVMSMLYYLGLMQWIIRKVGWIML VTTGSSPIESVVASGNIFVGQTESPLLVRPYLPYITKSELHAIMTAGFSTIAGSVLGAYISFGVPSSHLLTASVMSAPAS LAAAKLFWPETEKPKITLKNAMKMESGDSGNLLEAATQGASSSISLVANIAVNLIAFLALLSFMNSALSWFGNMFDYPQL SFELICSYIFMPFSFMMGVEWQDSFMVARLIGYKTFFNEFVAYEHLSKWIHLRKEGGPKFVNGVQQYISIRSEIIATYAL CGFANIGSLGIVIGGLTSMAPSRKRDIASGAVRALIAGTVACFMTACIAGILSSTPVDINCHHVLENAFNSTFPGNTTKV IACCQSLLSSTVAKGPGEVIPGGNHSLYSLKGCCTLLNPSTFNCNGISNTF