Alternative titles; symbols
HGNC Approved Gene Symbol: NT5C
Cytogenetic location: 17q25.1 Genomic coordinates (GRCh38): 17:75,130,228-75,131,742 (from NCBI)
Pyrimidine 5-prime nucleotidase (P5N; EC 3.1.3.5), also called uridine 5-prime monophosphate hydrolase (UMPH), catalyzes the dephosphorylation of the pyrimidine 5-prime monophosphates UMP and CMP to the corresponding nucleosides. There are 2 isozymes of pyrimidine 5-prime nucleotidase in red blood cells, referred to as type I (UMPH1; 606224) and type II (UMPH2).
Electrophoretic analysis shows a single band of UMPH enzyme activity in human cells but 2 distinct UMPH activities in rodent cells. Swallow et al. (1983) and Paglia et al. (1984) showed that in fact humans also possess 2 distinct UMPH isozymes that are not electrophoretically separable. This result was based on observations in persons who lacked UMPH1 but retained normal UMPH2 activity. Differences in substrate specificity distinguish the 2 isozymes. Deficiency of UMPH1 causes hemolytic anemia; see 266120.
5-prime(3-prime)-Deoxyribonucleotidase (DNT1) is a ubiquitous enzyme in mammalian cells with particularly high activity in lymphoid cells. Biochemically purified DNT1 has an apparent molecular mass of 45 kD and hydrolyzes 5-prime deoxyribonucleotides (dNTP) and 2-prime(3-prime)-dNTP and ribonucleotides but not 5-prime ribonucleotides (Hoglund and Reichard, 1990; Tjernshaugen and Fritzson, 1976). By micropeptide sequencing and database searching, Rampazzo et al. (2000) identified a full-length cDNA encoding mouse Dnt1. They also cloned a partial human DNT1 cDNA that lacked the 5-prime 181 bp present in the mouse sequence. The amino acid sequence predicted from the partial human cDNA is 83% identical to that of the mouse protein. Northern blot analysis revealed ubiquitous expression of 1.5- and 1.0-kb DNT1 transcripts, with highest expression in skeletal muscle, heart, and pancreas. SDS-PAGE and enzyme analysis showed that recombinant murine Dnt1 is expressed as a 25-kD enzyme that is active only when expressed from the first ATG and catalyzes nucleotide dephosphorylation, but lacks phosphotransferase activity. Recombinant human DNT1 was active only when fused with the 5-prime end of the mouse cDNA. Fluorescence microscopy indicated that DNT is expressed in the cytoplasm and nucleus and is not targeted to any specific organelle.
Wilson et al. (1986) demonstrated in somatic cell hybrids that UMPH2 cosegregated with 17q. Using mouse-Syrian hamster hybrids, Wilson et al. (1987) demonstrated synteny of Umph2 and Glk in the mouse, indicating that the Umph2 gene is on mouse chromosome 11. By means of chromosome-mediated gene transfer, Xu et al. (1988) demonstrated that UMPH2 is in a group of genes that are cotransfected along with the selectable marker TK1 (188300), which lies in the region 17q23.2-q25.3. UMPH2 cotransfected with the GHC genes (see 139250) with a high frequency. The order was thought to be: cen--GAA--UMPH2--GHC--TK1--GALK--qter.
By sequence analysis, Rampazzo et al. (2000) identified the DNT1 and DNT2 (605292) genes within genomic clones located on chromosome 17. They also found that the 2 genes have a similar genomic structure.
Anderson, J. A., Teng, Y.-S., Giblett, E. R. Stains for six enzymes potentially applicable to chromosomal assignment by cell hybridization. Cytogenet. Cell Genet. 14: 295-299, 1975.
Hoglund, L., Reichard, P. Cytoplasmic 5-prime(3-prime)-nucleotidase from human placenta. J. Biol. Chem. 265: 6589-6595, 1990. [PubMed: 2157703]
Paglia, D. E., Valentine, W. N., Brockway, R. A. Identification of thymidine nucleotidase and deoxyribonucleotidase activities among normal isozymes of 5-prime-nucleotidase in human erythrocytes. Proc. Nat. Acad. Sci. 81: 588-592, 1984. [PubMed: 6320196] [Full Text: https://doi.org/10.1073/pnas.81.2.588]
Rampazzo, C., Gallinaro, L., Milanesi, E., Frigimelica, E., Reichard, P., Bianchi, V. A deoxyribonucleotidase in mitochondria: involvement in regulation of dNTP pools and possible link to genetic disease. Proc. Nat. Acad. Sci. 97: 8239-8244, 2000. [PubMed: 10899995] [Full Text: https://doi.org/10.1073/pnas.97.15.8239]
Rampazzo, C., Johansson, M., Gallinaro, L., Ferraro, P., Hellman, U., Karlsson, A., Reichard, P., Bianchi, V. Mammalian 5-prime(3-prime)-deoxyribonucleotidase, cDNA cloning, and overexpression of the enzyme in Escherichia coli and mammalian cells. J. Biol. Chem. 275: 5409-5415, 2000. [PubMed: 10681516] [Full Text: https://doi.org/10.1074/jbc.275.8.5409]
Swallow, D. M., Turner, V. S., Hopkinson, D. A. Isozymes of rodent 5-prime-nucleotidase: evidence for two independent structural loci UMPH-1 and UMPH-2. Ann. Hum. Genet. 47: 9-17, 1983. [PubMed: 6301357] [Full Text: https://doi.org/10.1111/j.1469-1809.1983.tb00965.x]
Tjernshaugen, H., Fritzson, P. Subcellular distribution and activity in different rat tissues of a deoxyinosine-activated nucleotidase. Biochem. J. 154: 77-80, 1976. [PubMed: 1275914] [Full Text: https://doi.org/10.1042/bj1540077]
Wilson, D. E., Swallow, D. M., Povey, S. Assignment of the human gene for uridine 5-prime-monophosphate phosphohydrolase (UMPH2) to the long arm of chromosome 17. Ann. Hum. Genet. 50: 223-227, 1986. [PubMed: 2833155] [Full Text: https://doi.org/10.1111/j.1469-1809.1986.tb01042.x]
Wilson, D. E., Woodard, D., Sandler, A., Erickson, J., Gurney, A. Provisional assignment of the gene for uridine monophosphatase-2 (Umph-2) to mouse chromosome 11. Biochem. Genet. 25: 1-6, 1987. [PubMed: 3034234] [Full Text: https://doi.org/10.1007/BF00498947]
Xu, W., Gorman, P. A., Rider, S. H., Hedge, P. J., Moore, G., Prichard, C., Sheer, D., Solomon, E. Construction of a genetic map of human chromosome 17 by use of chromosome-mediated gene transfer. Proc. Nat. Acad. Sci. 85: 8563-8567, 1988. [PubMed: 3186746] [Full Text: https://doi.org/10.1073/pnas.85.22.8563]