Methylation: 1. In chemistry, the addition of a methyl group to a molecule. 2. On a protein level, the addition of a methyl group or groups to the amino acid arginine or lysine in a protein. 3. On a DNA level, the addition of a methyl group to a cytosine residue to convert it to 5-methylcytosine. Methylation of DNA occurs at CpG sites, where cytosine (C) lies next to guanine (G). The CpG sites are in regions near the promoters of a genes. These regions are known as CpG islands. The state of methylation of CpG islands is critical to both gene activity and gene expression.
CONTINUE SCROLLING OR CLICK HERE FOR RELATED ARTICLE
Reviewed on 12/21/2018