Disease relevance of NT5C3

• Functional analysis of pyrimidine 5'-nucleotidase mutants causing nonspherocytic hemolytic anemia [1].
• Inherited pyrimidine 5'-nucleotidase type I (P5'N-1) deficiency is the third most common erythrocyte enzymopathy that causes hemolysis [1].
• Human erythrocyte pyrimidine 5-nucleotidase, PN-I, is identical to p36, a protein associated to lupus inclusion formation in response to alpha-interferon [2].
• PN-I cDNA, coding for a 286-residue protein, was expressed in Escherichia coli, yielding a fully active recombinant enzyme [2].
• The prognostic value of cN-II and cN-III enzymes in adult acute myeloid leukemia [3].

High impact information on NT5C3

• 8). Three of these proteins (p70, p36 and p32.5) cross-react with antiserum to calelectrin, a Ca2+-binding protein (relative molecular mass 34,000 (34K] from the ray Torpedo marmorata, giving rise to their designation as calelectrin-related proteins [4].
• We now report that calelectrin, p36 and p32.5 contain a 17-amino-acid consensus sequence which is conserved and present in multiple copies [4].
• Gamma-IFN did not induce p36 or LI in any of these seven cell lines [5].
• These results along with previous results on the de novo synthesis of LI in the endoplasmic reticulum (which is involved in the processing and secretion of proteins) suggest a role for LI in the synthesis and secretion of p36 [5].
• The de novo synthesis of p36 with alpha-IFN treatment was shown by labeling the cell proteins with [35S] methionine before and after the addition of alpha-IFN [5].

Chemical compound and disease context of NT5C3

• We have previously purified PN-I, a pyrimidine nucleotidase whose deficiency is associated with hemolytic anemia [2].
• Biochemical and immunofluorescence studies have demonstrated that p36, a major substrate for the tyrosine-specific protein kinases induced by several sarcoma viruses and epidermal growth factor, is associated with plasma membranes and detergent-resistant cytoskeletal structures of cultured cells [6].
• Thus, this impairment of the pentose phosphate pathway appears to contribute to the pathogenesis of hemolysis in pyrimidine 5'-nucleotidase deficiency hemolytic anemia [7].
• To clarify the effect of antisense Ki-ras RNA on various pancreatic cancer cell lines, a plasmid expressing an antisense Ki-ras gene fragment (AS-K-ras-LNSX) was transduced into seven human pancreatic cancer cell lines (AsPC-1, MIA PaCa-2, PANC-1, PSN-1, BxPC-3, Hs 700T, and Hs 766T) by liposome-mediated transfection [8].
• Red cell pyrimidine 5'-nucleotidase and glutathione in myeloproliferative and lymphoproliferative disorders [9].

Biological context of NT5C3

• The DNA analysis was complicated by P5'N-1 pseudogenes found on chromosomes 4 and 7 [10].
• PN-I partial sequences were matched through the expressed sequence tag database with different human complementary DNA (cDNA) clones, whose sequences were exploited to screen a human placenta cDNA library [2].
• This approach generated a genomic DNA sequence that was used to search GenBank and identify the gene for P5'N-1 [10].
• We identified five novel mutations in nine families with P5N-I deficiency: two missense mutations (425C, 721C), one splice mutation (339C), one 1-bp insertion (251-insA-252) and one 9-bp deletion (del 192-200) [11].
• The sequence is located 6.2-kb downstream of the exon 2 and 2.7-kb upstream of the exon 3 sequence; consequently, the P5N-I gene encodes 11 exons, which span approximately 48 kb [11].

Anatomical context of NT5C3

• Human erythrocyte pyrimidine 5'-nucleotidase, PN-I [12].
• Raji-cell p36 was shown in Western blots with antipeptide antibodies to be induced at least 400-fold and by immunofluorescence microscopy to co-localize with the endoplasmic reticulum resident protein, protein disulfide isomerase [13].
• Two alternatively spliced forms of P5N-I mRNA have been identified, and we found another alternatively spliced form in reticulocytes, which included an additional 87-bp sequence [11].
• Here we have studied lymphoblastoid cell lines from control and UMPH-1 deficient patients to determine whether UMPH-1 can be detected in lymphoblastoid cells and whether the deficiency of UMPH-1 results in any measurable metabolic effects [14].
• These results, together with our previous work, suggest that the p36 protein is an integral part of the detergent-resistant proteinaceous network at the cytoplasmic face of the plasma membrane [6].

Associations of NT5C3 with chemical compounds

• Human erythrocyte pyrimidine 5'-nucleotidase, PN-I, catalyzes the dephosphorylation of pyrimidine nucleoside monophosphates [15].
• The mutant P5N-I with 721C (G241R) had lower affinity for cytidine monophosphate, suggesting that Gly241 is important for substrate binding [11].
• Two distinct isozymes of uridine 5'-monophosphate phosphohydrolase (UMPH) have been identified in mammalian cells [16].
• The p36 substrate of tyrosine-specific protein kinases co-localizes with non-erythrocyte alpha-spectrin antigen, p230, in surface lamina of cultured fibroblasts [6].
• Anti-p36 IgGs are able to immunoprecipitate a Triton X-100 soluble p36-pS complex, suggesting a direct interaction between p36 and pS [17].

Other interactions of NT5C3

• It was found that at least one reactive sulfhydryl group occurs in the UMPH1 isozyme but not in the UMPH2 isozyme [18].
• Our results show that high mRNA levels of cN-II and low mRNA levels of cN-III are correlated with a worse clinical outcome and suggest that these enzymes may have a role in sensitivity to ara-C in AML patients [3].
• Hemolytic anemia in hereditary pyrimidine 5'-nucleotidase deficiency: nucleotide inhibition of G6PD and the pentose phosphate shunt [7].
• SOX7 mRNA was significantly up-regulated in pancreatic cancer cell lines BxPC-3, PSN-1, Hs766T, and in 4 cases out of 8 cases of primary gastric cancer [19].
• OSR1 mRNA was significantly up-regulated in a pancreatic cancer cell line MIA PaCa-2, and was weakly expressed in gastric cancer cell lines OKAJIMA, MKN45, pancreatic cancer cell lines PANC-1, BxPC-3, AsPC-1, PSN-1, Hs766T, and esophageal cancer cell line TE10 [20].

Analytical, diagnostic and therapeutic context of NT5C3

• This immunoprecipitation was specific as it was abolished by a pS synthetic transit peptide, consistent with the transit sequence receptor function of p36 [17].
• Immunoelectron microscopy localized p36 to regions of the outer chloroplast membrane that are in close contact with the inner chloroplast membrane [17].
• We have used here polyclonal antisera and monoclonal antibodies in indirect immunofluorescence microscopy to study the subcellular location of p36 and the p230, which is a subplasmalemmal polypeptide showing immunologic cross-reactivity with erythrocyte alpha-spectrin [6].
• A 250,000-fold purification of pyrimidine 5'-nucleotidase from human erythrocytes has been achieved using a combination of DEAE-cellulose chromatography, ammonium sulfate fractionation, gel filtration, and isoelectric focusing [21].
• Thus, the p36 MBP kinase might be a common component of the diverse signaling pathways leading to apoptosis, and controlling this p36 MBP kinase pathway might be a novel strategy for cancer chemotherapy [22].

References