Definition
A very short peptide, often 2–4 residues, proposed to regulate gene expression; mostly studied by Russian groups.
Bioregulator peptides are very short synthetic peptides, often two to four amino acids, developed largely by Vladimir Khavinson and colleagues in St Petersburg from the 1980s onward. They were originally derived from tissue extracts, and the hypothesis is that they interact with DNA or chromatin to regulate gene expression in a tissue-specific way. The best-known example is epitalon (Ala-Glu-Asp-Gly), associated with the pineal gland and studied for telomerase activity in cell culture and lifespan in rodents. Most published work comes from a small number of related groups, independent replication is limited, and the evidence level is low.