Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.1.21 (thymidine kinase)
 7,561 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The macrophage colony-stimulating factor (M-CSF) is required for the growth and differentiation of mononuclear phagocytes. Previous studies have demonstrated that tumor necrosis factor (TNF) induces transcription of the M-CSF gene in human myeloid cells. The present work examined the effects of TNF on cis-acting elements in the M-CSF promoter. Deleted forms of the M-CSF promoter were linked to the chloramphenicol acetyltransferase (CAT) gene and transfected by electroporation into HL-60 promyelocytic leukemia cells. The results demonstrate that an enhancer responsive to TNF stimulation is located between positions -406 and -344 upstream to the transcription start site. The fragment from positions -419 to -304 was cloned 5' to the heterologous thymidine kinase (TK) promoter and linked to the CAT gene. Both orientations of this fragment enhanced TK-promoter activity in TNF-treated HL-60 cells. The results of gel mobility shift assays with the -419 to -304 fragment demonstrate binding of a constitutive nuclear protein. A TNF-inducible protein also bound to this fragment and resulted in a different mobility pattern. Binding of the TNF-induced nuclear protein to the -419 to -304 fragment was inhibited by an oligonucleotide containing the nuclear factor-kappa B (NF-kappa B) consensus sequence. DNA footprinting demonstrated protection of an NF-kappa B binding site at positions -377 to -368. Methylation interference assays showed that the TNF-induced protein made contact points with guanine residues in the same NF-kappa B sequence. Taken together, the findings provide evidence for involvement of an NF-kappa B-like factor in transcriptional regulation of the M-CSF gene.
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PMID:Involvement of a nuclear factor-kappa B-like protein in induction of the macrophage colony-stimulating factor gene by tumor necrosis factor. 191 81

The expression of seven enzymes involved in the biosynthesis of DNA was measured in HL-60 promyelocytic leukemia cells treated with dimethylsulfoxide (DMSO) or all-trans retinoic acid (RA) to gain information on their role in the termination of proliferation in cells undergoing granulocytic differentiation. The steady-state levels of the mRNAs for topoisomerase I, topoisomerase II. DNA polymerase-alpha, thymidylate synthase, thymidine kinase and hypoxanthine-guanine phosphoribosyltransferase progressively declined from day 3 to day 7 of exposure to the polar solvent or the retinoid suggesting that the expression of these enzymes is coordinately regulated. In contrast, a pronounced difference between the two inducers of differentiation occurred in the expression of the mRNA of the M2 subunit of ribonucleotide reductase, with DMSO causing virtually complete inhibition of the expression of the M2 subunit of the enzyme from day 5 through day 7, with no change in the steady-state levels of the mRNA being produced by retinoic acid. Measurement of the enzymatic activities of two of these catalysts, thymidylate synthase and thymidine kinase, in cells exposed to the two inducers of maturation corroborated the findings at the level of the mRNAs, with corresponding decreases in the activity of these enzymes. The findings collectively demonstrate that the down-regulation of the expression of a relatively wide variety of enzymes involved in DNA replication occurs as late events in the granulocytic differentiation of HL-60 cells, ensuring that cellular replication cannot occur in terminally differentiated cells.
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PMID:Regulation of the expression of enzymes involved in the replication of DNA in chemically-induced granulocytic differentiation of HL-60 leukemia cells. 968 95

The expression of a number of housekeeping enzymes of DNA biosynthesis was measured in HL-60 promyelocytic leukemia cells undergoing monocytic/macrophagic differentiation following treatment with 12-O-tetradecanoylphorbol 13-acetate (TPA) or 1alpha,25-dihydroxyvitamin D3 (vitamin D3). Progressive decreases in the steady-state levels of the mRNAs for thymidylate synthase, topoisomerase II, and hypoxanthine guanine phosphoribosyltransferase occurred following exposure to TPA or vitamin D3. In contrast, the steady-state levels of the mRNAs for thymidine kinase, topoisomerase I, and DNA polymerase-alpha did not decrease until days 3-5 of treatment with vitamin D3 and then progressively declined thereafter. The mRNAs for thymidine kinase and topoisomerase I decreased slightly and the mRNA for DNA polymerase-alpha by 30-40%, and then remained constant between days 1 to 3 of treatment with the phorbol ester. The M2 subunit of ribonucleotide reductase exhibited an even greater difference, with no change in the steady-state concentration of mRNA over 3 days of exposure to TPA or vitamin D3. On days 5-7 of treatment with vitamin D3, essentially complete loss of the expression of the mRNA for the M2 subunit of ribonucleotide reductase occurred. Measurement of the enzymatic activities of thymidylate synthase and thymidine kinase in cells exposed to either of the inducers of maturation corroborated the findings at the level of the mRNAs, with corresponding decreases in the activity of these enzymes. The results indicate that the down-regulation of the expression of housekeeping enzymes of DNA replication occurs as late events in HL-60 cells undergoing monocytic/macrophagic differentiation, implying that the decreases in their gene expression are the result of the termination of proliferation rather than an initiating event in the cessation of DNA biosynthesis.
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PMID:Regulation of the expression of enzymes involved in the replication of DNA in chemically induced monocytic/macrophagic differentiation of HL-60 leukemia cells. 968 96

A monkey kidney cDNA that encodes a nuclear regulatory factor was identified by expression and affinity binding to a synthetic retinoic acid response element (RARE) and was used to isolate human placental and rat germ cell cDNAs by hybridization. The cDNAs encode a 59-kDa protein [nuclear DEAF-1-related (NUDR)] which shows sequence similarity to the Drosophila Deformed epidermal autoregulatory factor-1 (DEAF-1), a nonhomeodomain cofactor of embryonic Deformed gene expression. Similarities to other proteins indicate five functional domains in NUDR including an alanine-rich region prevalent in developmental transcription factors, a domain found in the promyelocytic leukemia-associated SP100 proteins, and a zinc finger homology domain associated with the AML1/MTG8 oncoprotein. Although NUDR mRNA displayed a wide tissue distribution in rats, elevated levels of protein were only observed in testicular germ cells, developing fetus, and transformed cell lines. Nuclear localization of NUDR was demonstrated by immunocytochemistry and by a green fluorescent protein-NUDR fusion protein. Site-directed mutagenesis of a nuclear localization signal resulted in cytoplasmic localization of the protein and eliminated NUDR-dependent transcriptional activation. Recombinant NUDR protein showed affinity for the RARE in mobility shifts; however it was efficiently displaced by retinoic acid receptor (RAR)/retinoid X receptor (RXR) complexes. In transient transfections, NUDR produced up to 26-fold inductions of a human proenkephalin promoter-reporter plasmid, with minimal effects on the promoters for prodynorphin or thymidine kinase. Placement of a RARE on the proenkephalin promoter increased NUDR-dependent activation to 41-fold, but this RARE-dependent increase was not transferable to a thymidine kinase promoter. Recombinant NUDR protein showed minimal binding affinity for proenkephalin promoter sequences, but was able to select DNA sequences from a random oligonucleotide library that had similar core-binding motifs (TTCG) as those recognized by DEAF-1. This motif is also present between the half-sites of several endogenous RAREs. The derived consensus- binding motif recognized by NUDR (TTCGGGNNTTTCCGG) was confirmed by mobility shift and deoxyribonuclease I (DNase I) protection assays; however, the consensus sequence was also unable to confer NUDR-dependent transcriptional activation to the thymidine kinase promoter. Our data suggests that NUDR may activate transcription independently of promoter binding, perhaps through protein-protein interaction with basal transcription factors, or by activation of secondary factors. The sequence and functional similarities between NUDR and DEAF-1 suggest that NUDR may also act as a cofactor to regulate the transcription of genes during fetal development or differentiation of testicular cells.
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PMID:Characterization of a nuclear deformed epidermal autoregulatory factor-1 (DEAF-1)-related (NUDR) transcriptional regulator protein. 977 84