This book provides an update on recent advances in the field of ADP ribosylation reactions. The individual chapters represent the synopses of contributions which were presented at the Seventh International Symposium on ADP-Ribosylation Reactions, held in Vitznau, Switzer land, from September 23 to 27, 1984. This volume covers new devel opments in the field since the last meeting was held on this topic in 1982, in Tokyo. Therefore, the present text is not meant to form a comprehensive account of a specialized research area, but encompasses a collection of state-of-the-art reports from the vast majority of laboratories currently involved in ADP-ribosylation work. For the sake of rapid publication, the editorial policy was to ensure easy accessibility of information contained in individual articles rather than to provide elaborate cross references or reference to work published prior to 1982. However, a detailed subject index will help the reader find complementary information. The enzymes of ADP-ribose metabolism have not yet acquired universally acceptable trivial names and the Enzyme Commission has not yet defmitely decided on formal appellations. Consequently, a variety of names for the nuclear enzyme appear in this book, including nuc1ear(ADP-ribosyl)transferase, poly(ADP-ribose) polymerase, or synthetase or synthase. Hopefully, a common convention will soon be established. The Seventh International Symposium on ADP-Ribosylation Reac tions was only possible because of the generous support which we have been given by our sponsors, listed below."

In 1966, a paper entitled "On the formation of a novel adenylylic compound by enzymatic extracts of liver nuclei" from Paul Mandel's laboratory in Strasbourg, France, planted the seed for a rapidly growing new field of biological research focusing on ADP-ribosylation reactions. The development of this field over the past 2 decades reflects very much a modern trend of biological research. As more detailed knowledge accumulates, enigmatic phenomena turn into concepts which create their own enigmata. This process tends to favor the development of multiple, seemingly disconnected, research lines until simplicity emerges from chaos and unifying concepts substitute for controversy. It appears that the field of ADP-ribosylation reactions has not yet attained this latter stage. For example, with the identification of two different classes of ADP-ribosylation reactions, i.e., mono-ADP-ribosyla tion and poly-ADP-ribosylation reactions, the field split very early into two separate branches of research. With the present volume, we have divided the task of reviewing these two classes of ADP ribosylation accordingly, although their coexistence in eukaryotes may involve a closer functional linkage than hitherto recognized."