Fig. 1.

Epigenetic regulation. Schematic diagram of DNA and associated epigenetic modifications: extensive crosstalk between DNA methyltransferases, histone modification enzymes and chromatin remodeling proteins has been documented. For example, methyl-binding proteins, such as MBD2, can directly or indirectly recruit both histone deacetylases and histone methyltransferases to nucleosomes in methylated loci. Methylation of histone H3 lysine 9 can be bound by HP1, which in turn can recruit histone and DNA methyltransferases reinforcing chromatin compaction and silencing. HDAC, histone deacetylase; DNMT1, DNA methyltransferase 1; HP1, heterochromatin protein 1; HMT, histone methyltransferase; MBD, methyl binding domain protein; HAT, histone acetyltransferase; Ac, acetyl; Me, methyl; Pol II, RNA polymerase II.