Picchianti M, Del Vecchio M, Di Marcello F, Biagini M, Veggi D, Norais N, Rappuoli R, Pizza M, Balducci E. Auto ADP-ribosylation of NarE, a Neisseria meningitidis ADP-ribosyltransferase, regulates its catalytic activities.
FASEB J 2013;
27:4723-30. [PMID:
23964075 DOI:
10.1096/fj.13-229955]
[Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
NarE is an arginine-specific mono-ADP-ribosyltransferase identified in Neisseria meningitidis that requires the presence of iron in a structured cluster for its enzymatic activities. In this study, we show that NarE can perform auto-ADP-ribosylation. This automodification occurred in a time- and NAD-concentration-dependent manner; was inhibited by novobiocin, an ADP-ribosyltransferase inhibitor; and did not occur when NarE was heat inactivated. No reduction in incorporation was evidenced in the presence of high concentrations of ATP, GTP, ADP-ribose, or nicotinamide, which inhibits NAD-glycohydrolase, impeding the formation of free ADP-ribose. Based on the electrophoretic profile of NarE on auto-ADP-ribosylation and on the results of mutagenesis and mass spectrometry analysis, the auto-ADP-ribosylation appeared to be restricted to the addition of a single ADP-ribose. Chemical stability experiments showed that the ADP-ribosyl linkage was sensitive to hydroxylamine, which breaks ADP-ribose-arginine bonds. Site-directed mutagenesis suggested that the auto-ADP-ribosylation site occurred preferentially on the R(7) residue, which is located in the region I of the ADP-ribosyltransferase family. After auto-ADP-ribosylation, NarE showed a reduction in ADP-ribosyltransferase activity, while NAD-glycohydrolase activity was increased. Overall, our findings provide evidence for a novel intramolecular mechanism used by NarE to regulate its enzymatic activities.
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