(420g) Effects of DNA Methylation On the Self-Assembly of a Chromatin Fiber

DNA in eukaryotic cells is folded into an organized structure facilitated by a protein complex, i.e., a histone octamer. This protein-DNA complex, known as a chromatin, regulates gene expression in eukaryotic cells by limiting the accessibility of genomic DNA sequences. DNA methylation, i.e., the addition of a methyl group to a nucleotide, is known as an epigenetic mark for regulating gene expression in eukaryotic cells. Besides being a targeted site for many chromatin-binding proteins, DNA methylation has been recently postulated to directly mediate gene expression by affecting the structure of a chromatin. To verify this hypothesis and to reveal the detailed roles of DNA methylation in chromatin structure, this study examines the effects of DNA methylation on the assembling and stability of a nucleosome, i.e., the structural repeating unit of a chromatin, using various biophysical approaches. This knowledge will shed light on the mechanism of DNA packaging in eukaryotic cells.