Equilibrative nucleoside transporter 1
Equilibrative nucleoside transporter 1 (ENT1) is a protein that in humans is encoded by the SLC29A1 gene.[5][6] Multiple alternatively spliced variants, encoding the same protein, have been found for this gene.[7]
Function
This gene is a member of the equilibrative nucleoside transporter family. The gene encodes a transmembrane glycoprotein that localizes to the plasma and mitochondrial membranes and mediates the cellular uptake of nucleosides from the surrounding medium. The protein is categorized as an equilibrative (as opposed to concentrative) transporter that is sensitive to inhibition by nitrobenzylmercaptopurine ribonucleoside (NBMPR). Nucleoside transporters are required for nucleotide synthesis in cells that lack de novo nucleoside synthesis pathways, and are also necessary for the uptake of cytotoxic nucleosides used for cancer and viral chemotherapies.[7]
Genomics
The gene encoding this protein is located on the short arm of chromosome 6 at 6p21.2-p21.1 on the Watson (plus) strand. It is 14,647 bases in length. The encoded protein has 456 amino acid residues with 11 predicted transmembrane domains. The predicted molecular weight is 50.219 kiloDaltons. The protein is post translationally glycosylated and expressed in all tissue with the apparent exception of skeletal muscle. The highest levels are found in the liver, heart, testis, spleen, lung, kidney and brain.
Interactive pathway map
Click on genes, proteins and metabolites below to link to respective articles.[§ 1]
- The interactive pathway map can be edited at WikiPathways: "FluoropyrimidineActivity_WP1601".
Clinical
Mutations in this gene have been associated with H syndrome, pigmented hypertrichosis with insulin dependent diabetes and Faisalabad histiocytosis.[8]
References
- GRCh38: Ensembl release 89: ENSG00000112759 - Ensembl, May 2017
- GRCm38: Ensembl release 89: ENSMUSG00000023942 - Ensembl, May 2017
- "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
- "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
- Griffiths M, Beaumont N, Yao SY, Sundaram M, Boumah CE, Davies A, Kwong FY, Coe I, Cass CE, Young JD, Baldwin SA (Jan 1997). "Cloning of a human nucleoside transporter implicated in the cellular uptake of adenosine and chemotherapeutic drugs". Nat Med. 3 (1): 89–93. doi:10.1038/nm0197-89. PMID 8986748.
- Coe IR, Griffiths M, Young JD, Baldwin SA, Cass CE (Feb 1998). "Assignment of the human equilibrative nucleoside transporter (hENT1) to 6p21.1-p21.2". Genomics. 45 (2): 459–60. doi:10.1006/geno.1997.4928. PMID 9344680.
- "Entrez Gene: SLC29A1 solute carrier family 29 (nucleoside transporters), member 1".
- Bolze A, Abhyankar A, Grant AV, Patel B, Yadav R, Byun M, Caillez D, Emile JF, Pastor-Anglada M, Abel L, Puel A, Govindarajan R, de Pontual L, Casanova JL (2012). "A Mild Form of SLC29A3 Disorder: A Frameshift Deletion Leads to the Paradoxical Translation of an Otherwise Noncoding mRNA Splice Variant". PLoS ONE. 7 (1): e29708. doi:10.1371/journal.pone.0029708. PMC 3251605. PMID 22238637.
Further reading
- Bonaldo MF, Lennon G, Soares MB (1997). "Normalization and subtraction: two approaches to facilitate gene discovery". Genome Res. 6 (9): 791–806. doi:10.1101/gr.6.9.791. PMID 8889548.
- Griffiths M, Yao SY, Abidi F, et al. (1998). "Molecular cloning and characterization of a nitrobenzylthioinosine-insensitive (ei) equilibrative nucleoside transporter from human placenta". Biochem. J. 328 (3): 739–43. doi:10.1042/bj3280739. PMC 1218980. PMID 9396714.
- Lum PY, Ngo LY, Bakken AH, Unadkat JD (2000). "Human intestinal es nucleoside transporter: molecular characterization and nucleoside inhibitory profiles". Cancer Chemother. Pharmacol. 45 (4): 273–8. doi:10.1007/s002800050040. PMID 10755314.
- Sundaram M, Yao SY, Ingram JC, et al. (2002). "Topology of a human equilibrative, nitrobenzylthioinosine (NBMPR)-sensitive nucleoside transporter (hENT1) implicated in the cellular uptake of adenosine and anti-cancer drugs". J. Biol. Chem. 276 (48): 45270–5. doi:10.1074/jbc.M107169200. PMID 11584005.
- SenGupta DJ, Lum PY, Lai Y, et al. (2002). "A single glycine mutation in the equilibrative nucleoside transporter gene, hENT1, alters nucleoside transport activity and sensitivity to nitrobenzylthioinosine". Biochemistry. 41 (5): 1512–9. doi:10.1021/bi015833w. PMID 11814344.
- Yao SY, Ng AM, Vickers MF, et al. (2002). "Functional and molecular characterization of nucleobase transport by recombinant human and rat equilibrative nucleoside transporters 1 and 2. Chimeric constructs reveal a role for the ENT2 helix 5-6 region in nucleobase translocation". J. Biol. Chem. 277 (28): 24938–48. doi:10.1074/jbc.M200966200. PMID 12006583.
- Galmarini CM, Thomas X, Calvo F, et al. (2002). "Potential mechanisms of resistance to cytarabine in AML patients". Leuk. Res. 26 (7): 621–9. doi:10.1016/S0145-2126(01)00184-9. PMID 12008078.
- Lai Y, Bakken AH, Unadkat JD (2002). "Simultaneous expression of hCNT1-CFP and hENT1-YFP in Madin-Darby canine kidney cells. Localization and vectorial transport studies". J. Biol. Chem. 277 (40): 37711–7. doi:10.1074/jbc.M204986200. PMID 12097333.
- Sankar N, Machado J, Abdulla P, et al. (2002). "Comparative genomic analysis of equilibrative nucleoside transporters suggests conserved protein structure despite limited sequence identity". Nucleic Acids Res. 30 (20): 4339–50. doi:10.1093/nar/gkf564. PMC 137128. PMID 12384580.
- Reiman T, Clarke ML, Dabbagh L, et al. (2003). "Differential expression of human equilibrative nucleoside transporter 1 (hENT1) protein in the Reed-Sternberg cells of Hodgkin's disease". Leuk. Lymphoma. 43 (7): 1435–40. doi:10.1080/1042819022386725. PMID 12389626.
- Strausberg RL, Feingold EA, Grouse LH, et al. (2003). "Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences". Proc. Natl. Acad. Sci. U.S.A. 99 (26): 16899–903. doi:10.1073/pnas.242603899. PMC 139241. PMID 12477932.
- Mangravite LM, Xiao G, Giacomini KM (2003). "Localization of human equilibrative nucleoside transporters, hENT1 and hENT2, in renal epithelial cells". Am. J. Physiol. Renal Physiol. 284 (5): F902–10. doi:10.1152/ajprenal.00215.2002. PMID 12527552.
- Szkotak AJ, Ng AM, Man SF, et al. (2003). "Coupling of CFTR-mediated anion secretion to nucleoside transporters and adenosine homeostasis in Calu-3 cells". J. Membr. Biol. 192 (3): 169–79. doi:10.1007/s00232-002-1073-x. PMID 12820662.
- Lai Y, Tse CM, Unadkat JD (2004). "Mitochondrial expression of the human equilibrative nucleoside transporter 1 (hENT1) results in enhanced mitochondrial toxicity of antiviral drugs". J. Biol. Chem. 279 (6): 4490–7. doi:10.1074/jbc.M307938200. PMID 14607828.
- Lehner B, Semple JI, Brown SE, et al. (2004). "Analysis of a high-throughput yeast two-hybrid system and its use to predict the function of intracellular proteins encoded within the human MHC class III region". Genomics. 83 (1): 153–67. doi:10.1016/S0888-7543(03)00235-0. PMID 14667819.
- Ota T, Suzuki Y, Nishikawa T, et al. (2004). "Complete sequencing and characterization of 21,243 full-length human cDNAs". Nat. Genet. 36 (1): 40–5. doi:10.1038/ng1285. PMID 14702039.
- Endres CJ, Sengupta DJ, Unadkat JD (2004). "Mutation of leucine-92 selectively reduces the apparent affinity of inosine, guanosine, NBMPR [S6-(4-nitrobenzyl)-mercaptopurine riboside] and dilazep for the human equilibrative nucleoside transporter, hENT1". Biochem. J. 380 (Pt 1): 131–7. doi:10.1042/BJ20031880. PMC 1224139. PMID 14759222.
- Gerhard DS, Wagner L, Feingold EA, et al. (2004). "The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC)". Genome Res. 14 (10B): 2121–7. doi:10.1101/gr.2596504. PMC 528928. PMID 15489334.
This article incorporates text from the United States National Library of Medicine, which is in the public domain.