DNA methylation

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DNA methylation can occur in either the [[Cytosine|cytosine]] or [[Adenine|adenine]] bases, cytosine methylation is generally found in [[Eukaryotic|eukaryotic]] cells whilst both but mainly [[Adenine methylation|adenine methylation]] can be found in [[Bacteria|bacteria]]<ref>D. T. Meštrović, "DNA Methylation in Bacteria," News Medical Life Sciences and Medicine, 10 09 2014. [Online]. Available: http://www.news-medical.net/health/DNA-Methylation-in-Bacteria.aspx. [Accessed 23 11 2015].</ref>. Methylation is the addition of a methyl group to another chemical substance. DNA methylation results in the addition of a [[Methyl group|methyl group]] to carbon number five in the respective base by one of three enzymes called DNMT1, DNMT3A or DNMT3B. DNMT refers to an [[Enzyme|enzyme]] [[DNA methylase|DNA methyltransferase]]. These enzymes usually add a methyl group to CpG (i.e a C that is followed by a G) which are abundantly found in the promoter region of a DNA, called [[CpG islands|CpG islands]], as stated by Professor [[Adrian Bird|Adrian Bird]] in one of his published papers<ref>Nessa Carey, The Epigenetics Revolution.</ref>. As an example, when cytosine is methylated it becomes [[5-methylcystosine|5-methylcystosine]]<ref>D. L. a. E. W. Jones, "Genetics Analysis of Genes and Genomes 7th Edition," in Epigenetic Mechanisms of Transcriptional Regulation, London, Jones and Bartlett Publishers, 20009, p. 411.</ref>. This change often occurs in the major grooves of the DNA strand, resulting in transcription factors being unable to bind to the area<ref>Klug WS, Cummings MR, Spencer CA, Palladino MA. Concepts of genetics. 11th ed. Harlow (England): Pearson; 2016. p. 708-17</ref>.  
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[[DNA|DNA]] methylation can occur in either the [[Cytosine|cytosine]] or [[Adenine|adenine]] bases, cytosine methylation is generally found in [[Eukaryotic|eukaryotic]] cells whilst both but mainly [[Adenine methylation|adenine methylation]] can be found in [[Bacteria|bacteria]]<ref>D. T. Meštrović, "DNA Methylation in Bacteria," News Medical Life Sciences and Medicine, 10 09 2014. [Online]. Available: http://www.news-medical.net/health/DNA-Methylation-in-Bacteria.aspx. [Accessed 23 11 2015].</ref>. Methylation is the addition of a methyl group to another chemical substance. DNA methylation results in the addition of a [[Methyl group|methyl group]] to carbon number five in the respective base by one of three enzymes called DNMT1, DNMT3A or DNMT3B. DNMT refers to an [[Enzyme|enzyme]] [[DNA methylase|DNA methyltransferase]]. These enzymes usually add a methyl group to CpG (i.e a C that is followed by a G) which are abundantly found in the promoter region of a DNA, called [[CpG islands|CpG islands]], as stated by Professor [[Adrian Bird|Adrian Bird]] in one of his published papers<ref>Nessa Carey, The Epigenetics Revolution.</ref>. As an example, when cytosine is methylated it becomes [[5-methylcystosine|5-methylcystosine]]<ref>D. L. a. E. W. Jones, "Genetics Analysis of Genes and Genomes 7th Edition," in Epigenetic Mechanisms of Transcriptional Regulation, London, Jones and Bartlett Publishers, 20009, p. 411.</ref>. This change often occurs in the major grooves of the DNA strand, resulting in transcription factors being unable to bind to the area<ref>Klug WS, Cummings MR, Spencer CA, Palladino MA. Concepts of genetics. 11th ed. Harlow (England): Pearson; 2016. p. 708-17</ref>.  
  
 
Methylation of DNA greatly affects gene expression. The effect of DNA methylation is that those methylated areas of the DNA are not sequenced during [[DNA Transcription|DNA Transcription]] and therefore the affected [[Genes|genes]] are silenced, proceeding to show [[Phenotypes|phenotypic]] change. In this way, DNA methylation plays a main role in epigenetics.  
 
Methylation of DNA greatly affects gene expression. The effect of DNA methylation is that those methylated areas of the DNA are not sequenced during [[DNA Transcription|DNA Transcription]] and therefore the affected [[Genes|genes]] are silenced, proceeding to show [[Phenotypes|phenotypic]] change. In this way, DNA methylation plays a main role in epigenetics.  
  
=== Methylation of a gene, addition of a methyl group (-CH3)[1], is catalyzed by the family of enzymes DNA-methyltransferases (DNMTs) and occurs at the 5-carbon on a cytosine ring; the methyl group projects into the major groove of the DNA double helix, causing the DNA-histone complex to become more tightly condensed, which prevents/negatively affects the binding of transcriptional factors to promoter regions or induces deacetylation of the histone proteins which inhibits transcription of the DNA sequence to mRNA.<br> ===
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Methylation of a [[gene|gene]], addition of a methyl group (-CH<sub>3</sub>), is catalyzed by the family of enzymes [[DNA-methyltransferases|DNA-methyltransferases]] (DNMTs) and occurs at the 5-carbon on a cytosine ring; the [[methyl group|methyl group]] projects into the major groove of the DNA double helix, causing the DNA-histone complex to become more tightly condensed, which prevents/negatively affects the binding of transcriptional factors to promoter regions or induces deacetylation of the [[histone|histone]] proteins which inhibits transcription of the DNA sequence to [[mRNA|mRNA]].

Revision as of 19:35, 10 December 2018

DNA methylation can occur in either the cytosine or adenine bases, cytosine methylation is generally found in eukaryotic cells whilst both but mainly adenine methylation can be found in bacteria[1]. Methylation is the addition of a methyl group to another chemical substance. DNA methylation results in the addition of a methyl group to carbon number five in the respective base by one of three enzymes called DNMT1, DNMT3A or DNMT3B. DNMT refers to an enzyme DNA methyltransferase. These enzymes usually add a methyl group to CpG (i.e a C that is followed by a G) which are abundantly found in the promoter region of a DNA, called CpG islands, as stated by Professor Adrian Bird in one of his published papers[2]. As an example, when cytosine is methylated it becomes 5-methylcystosine[3]. This change often occurs in the major grooves of the DNA strand, resulting in transcription factors being unable to bind to the area[4].

Methylation of DNA greatly affects gene expression. The effect of DNA methylation is that those methylated areas of the DNA are not sequenced during DNA Transcription and therefore the affected genes are silenced, proceeding to show phenotypic change. In this way, DNA methylation plays a main role in epigenetics.

Methylation of a gene, addition of a methyl group (-CH3), is catalyzed by the family of enzymes DNA-methyltransferases (DNMTs) and occurs at the 5-carbon on a cytosine ring; the methyl group projects into the major groove of the DNA double helix, causing the DNA-histone complex to become more tightly condensed, which prevents/negatively affects the binding of transcriptional factors to promoter regions or induces deacetylation of the histone proteins which inhibits transcription of the DNA sequence to mRNA.


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