Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.1.1.37 (DNA methyltransferase)
 4,983 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Actinomycin D caused the production of hypomethylated DNA in cultured Friend erythroleukemia cells at cell culture concentrations of 1-4 ng per ml. Inhibition of DNA methyltransferase in cell-free assays was kinetically complex, with mixed-type inhibition. Cornish-Bowden graphical analysis was used to derive a Ki of about 35 nmol Act D per mg DNA. Although nuclei from drug-treated cells were found to contain hypomethylated DNA and DNA methyltransferase could be extracted from the nuclei, the methyl-accepting ability of DNA in whole nuclei themselves was not elevated. We conclude that the low level of Act D bound to DNA in the nuclei is sufficient to prevent the remethylation of hypomethylated sites.
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PMID:Inhibition of DNA methylation in Friend erythroleukemia cells by actinomycin D. 261 50

DNA methylase from Ehrlich's ascites tumour cells preferentially methylates DNA with high GC content. The methylase activity was not affected by the presence of the oligonucleotides, dCdG or dCdCdGdG, which are known to be part of the methyl-acceptor sequence for mammalian DNA methylase. DNA from 5-azacytidine-treated ascites cells was a good methyl acceptor. Actinomycin D, ethydium bromide and quinacrine inhibited the methylase activity. Distamycin A also inhibited the methylation of DNA from 5-azacytidine-treated ascites cells, but did not inhibit the methylation of (dG,dC)n. The inhibitory effect of all these drugs was overcome by increasing the DNA concentration. Non-competitive type inhibition in regard to S-adenosylmethionine was observed with all the DNA-binding drugs.
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PMID:Effect of DNA-binding drugs on the activity of DNA methylase from Ehrlich's ascites tumour cells. 713 12

Upon the onset of mouse myoblast differentiation there is a rapid drop in DNA methyltransferase activity followed by a genome wide demethylation [Jost and Jost (1994) J. Biol. Chem. 269, 10040-10043]. Here we show by using specific antibodies directed against DNA methyltransferase that upon differentiation there was a rapid drop in nuclear DNA methyltransferase whilst the internal control histone H1 remained constant. The loss of nuclear methyltransferase was not due to a translocation of the enzyme from the nucleus to the cytoplasm where there was an increase in creatine phosphokinase protein. In vitro run on experiments carried out with growing and differentiating myoblast nuclei showed no difference in the rate of DNA methyltransferase mRNA synthesis. As measured by Northern blot hybridization the relative half life of DNA methyltransferase mRNA in growing and differentiating cells in the presence of Actinomycin D was 5 h and 1 h 30 min respectively, whereas in the same cells the half life of histone H4 mRNA was in both cases 80 min. As measured by a combination of pulse chase experiments with labeled leucine and immunoprecipitation, the relative half-life of DNA methyltransferase in growing and differentiating cells was approximately 18 h and 4 h 30 min respectively.
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PMID:In differentiating mouse myoblasts DNA methyltransferase is posttranscriptionally and posttranslationally regulated. 875 2