Bacterial toxins and the role of ADP-ribosylation.

Studies on the pathogenesis of "Whooping Cough" and cholera have resulted in the discovery of important pathways in the regulation of cellular metabolism leading to the realization of a complex family of proteins that appear to play central roles in the regulation of hormonal responses and which utilize guanine nucleotides in their mechanism of action. The fact that these bacterial toxins interfere so precisely with the complex regulation of eukaryotic cellular metabolism and the discovery of analogous enzymes within the cytosol of eukaryotic cells suggests that ADP-ribosylation may be an important pathway through which the cell can establish its responsiveness to its environment. Clearly, future work directed towards the role of ADP-ribosylation and towards the mechanisms of the regulation of these endogenous ADP-ribosyltransferases and lyases may provide great insights into the mechanisms of hormone action.