Novel genetic and epigenetic alterations in ... - Ous-research.no

IntroductionFigure 3. Methylation effect on chromatin. In an expressed state, the chromatin structure in proximity tothe gene is loosely packed, a state recognized by acetylation of the histone tails (i). The adding of methyl groupsto the CpG sites (ii) is associated with a more densely packed chromatin and can be obtained in several ways. Afamily of proteins with a methyl-binding domain (MBD) binds to the DNA-bound methyl groups. Dependingon which protein that binds, the binding partners and the effects vary slightly (iii – v). The net effect is thatRNA transcription is impaired due to blocking of transcription factors, either by inhibiting the direct binding(vi) or by condensation of the chromatin structure (vii).17