post-translational protein modification protein poly-ADP-ribosylation protein poly(ADP-ribose) synthesis biological_process GO:0070212 The transfer of multiple ADP-ribose residues from NAD to a protein amino acid, forming a poly(ADP-ribose) chain. poly(ADP-ribose) addition to protein protein poly(ADP-ribose) metabolism addition of poly-ADP-ribose to protein protein amino acid poly-ADP-ribosylation