Mono-ADP-ribosylation of Gs by an eukaryotic arginine-specific ADP-ribosyltransferase stimulates the adenylate cyclase system |
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| Authors: | K Inageda H Nishina S Tanuma |
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| Institution: | Department of Life Science, Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, Japan. |
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| Abstract: | An arginine-specific ADP-ribosyltransferase, named ADP-ribosyltransferase A, was partially purified from human platelets using polyarginine as an ADP-ribose acceptor. When human platelet membranes were incubated with the transferase A in the presence of NAD+, Gs, a stimulatory guanine nucleotide-binding protein of the adenylate cyclase was specifically mono-ADP-ribosylated. ADP-ribose transfer to Gs by this enzyme was suppressed when membranes were pre-ADP-ribosylated by cholera toxin. Incubation of membranes with the transferase A resulted in activation of the adenylate cyclase system. This stimulatory effect of the transferase A on the adenylate cyclase system was inhibited by the presence of polyarginine. These results indicate a role of ADP-ribosyltransferase A in regulation of the adenylate cyclase system via endogenous mono-ADP-ribosylation of Gs. |
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