Transglutaminases and Their Regulation: Implications for Polyamine Metabolism

Transglutaminases are a group of enzymes that catalyze the posttranslational modification of protein-bound glutamine residues. It appears that the major physiological role of these enzymes is to crosslink proteins by promoting the formation of isopeptide bonds between protein-bound glutamine and lysine residues. These enzymes also catalyze the covalent conjugation of polyamines to proteins and this latter activity has led to speculation about their involvement in the biology of polyamine action. In this report we would like to present a brief review of the theoretical and experimental evidence for considering transglutaminases as components in polyamine metabolism.