The majority of methylated deoxycytidines in human DNA are not in the CpG dinucleotide
| Autor: | W.P. Diver, P.J. Crowther, D.M. Woodcock |
|---|---|
| Rok vydání: | 1987 |
| Předmět: |
Cytidine monophosphate
Guanosine Biophysics Cell Biology Methylation DNA Biology Cytosine Nucleotides Biochemistry Molecular biology Deoxycytidine chemistry.chemical_compound Cytosine nucleotide Differentially methylated regions CpG site chemistry DNA methylation Cytidine Monophosphate Humans Human genome Molecular Biology Dinucleoside Phosphates |
| Zdroj: | Biochemical and biophysical research communications. 145(2) |
| ISSN: | 0006-291X |
| Popis: | The only natural postsynthetic modification known to occur in mammalian DNA is the methylation in the 5 position of deoxycytidines. Of the four 5'-CpN-3' dinucleotides (ie. CpG, CpC, CpA, and CpT), the dinucleotide which contains the highest proportion of deoxycytidines methylated is CpG, with 40 to 80% methylation in different mammalian genomes. It has also been shown that CpA, CpT, and CpC are methylated as well but to a much lower extent. Here we report the result of a full nearest neighbour analysis (together with quantitation of methylation levels in the 4 CpN dinucleotides) for DNA from human spleen. Using the values we have calculated the overall frequencies for all the methylated dinucleotides in the human genome. Because of the relative underrepresentation (by 7 to 10 fold) of the CpG dinucleotide, only 45.5% of total mC was present in mCpG, with 54.5% in mCpA, mCpT plus mCpC. These calculations have implications for studies into the function and significance of DNA methylation in mammalian cells. |
| Databáze: | OpenAIRE |
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