Peptide KE in Human Proteome

Peptide KE exhibits immunoprotective, geroprotective, and oncostatic activities and stimulates functional activity of fibroblasts. The KE motif is present in amino acid sequences of some cytokines and peptide hormones functionally similar to KE peptide. However, the relationship between the presence of KE motif and protein functions on the scale of known human proteome has not yet received sufficient attention. The incidence of bioregulatory peptide KE in proteins of various functional groups constituting human proteome is studied. The study is carried out with the use of the available data on the human proteome (UniProt portal) comprising 20,417 proteins. The levels of KE motifs were maximum in cytoplasmic and nuclear proteins, while the presence of KE in the membrane and all other proteins was the minimum. KE peptide molecules released from nuclear proteins during limited proteolysis can bind to DNA and regulate gene expression.