Characterization of the endogenous ADP-ribosylation of the G protein beta subunit

摘要

Mono-ADP-ribosylation is a post-translational modification of cellular proteins that has been implicated in the regulation of signal transduction, muscle cell differentiation and protein trafficking and secretion, although the substrates of this reaction have been poorly characterized and its functional significance is even less understood [1]. A fundamental step in understanding the role of endogenous ADP-ribosylation under physiological conditions is the characterization of the enzymes and substrates specific for this reaction. We have recently characterized the endogenous ADP-ribosylation of the heterotrimeric G protein beta subunit [2,3]. The alpha subunits of G proteins have been previously described as being substrates of endogenous ADP-ribosyltransferases, whereas no evidence had so far been reported on the ADP-ribosylation of betagamma subunits. In the following, we will also summarize evidence that this modification can modulate betagamma activity [2,3].