Physiological relevance of the endogenous mono(ADP-ribosyl)ation of cellular proteins


D. Corda or M. Di Girolamo, Consorzio Mario Negri Sud, Department of Cell Biology and Oncology, 66030 Santa Maria Imbaro (Chieti), Italy
Fax: +39 0872 570 412
Tel: +39 0872 570 338


The mono(ADP-ribosyl)ation reaction is a post-translational modification that is catalysed by both bacterial toxins and eukaryotic enzymes, and that results in the transfer of ADP-ribose from βNAD+ to various acceptor proteins. In mammals, both intracellular and extracellular reactions have been described; the latter are due to glycosylphosphatidylinositol-anchored or secreted enzymes that are able to modify their targets, which include the purinergic receptor P2X7, the defensins and the integrins. Intracellular mono(ADP-ribosyl)ation modifies proteins that have roles in cell signalling and metabolism, such as the chaperone GRP78/BiP, the β-subunit of heterotrimeric G-proteins and glutamate dehydrogenase. The molecular identification of the intracellular enzymes, however, is still missing. A better molecular understanding of this reaction will help in the full definition of its role in cell physiology and pathology.