Fig. 1.

Schematic overview of peptide effects on different epigenetic mechanisms. (a) Short peptides inhibit DNA methylation by blocking DNA methyltransferase binding or initiation of strand separation. (b) BCM7, GM7, and Aβ suppress DNA methylation by inhibiting cysteine uptake and lowering the SAM/SAH ratio in the cell. (c) HIP inhibits histone methylation indirectly by suppressing the FOXO1 transcription factor and subsequent menin binding and histone methyltransferase recruitment. (d) Lunasin blocks H3 and H4 histone acetylations by preventing HAT interaction. (e) Cyclic depsi- and tetrapeptides inhibit histone deacetylases by interaction with zinc atoms in the binding pocket of the enzyme. (f, g) Synthetic peptide antagonists block the interaction sites of the HDM and HMT enzymes. (h) Synthetic peptides either promote or suppress Dicer-mediated maturation of miRNA