[Epigenetic aspects of peptide regulation of aging]

Endogenous short peptides presented in the cyto- and nucleoplasm, are products of specific proteolysis of nuclear proteins in the proteasome. They are short blocks in sequence of amino acid residues with charged side groups and are characterized by a high local concentration of electrostatic charges of opposite signs. The peptides are capable of complementarily binding to specific short sequences of nucleotides in DNA strands. This binding can significantly reduce the strength of proton bonds in DNA double helix structure and thus stimulate the process of chain separation required for genes transcription and replication. The aging of organisms is always followed by the decrease in methylation of the genome. Age-related decrease in methylation of repeated nucleotide sequences in the genome leads to an increase in site-specific binding of short peptides to DNA. In turn, the binding of peptide inhibits the hydrolysis of demethylated DNA regions by endonucleases. The experimental data on the peptide interaction with methylated DNA point to the participation of oligopeptides in the epigenetic regulation of the ageing.