HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Supplementary table All Versions of this Article: mic.0.028399-0v1 155/11/3710    most recent Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Google Scholar Articles by Uchida, I. Articles by Kubota, T. PubMed PubMed Citation Articles by Uchida, I. Articles by Kubota, T. Agricola Articles by Uchida, I. Articles by Kubota, T.

Salmonella enterica serotype Typhimurium DT104 ArtA-dependent modification of pertussis toxin-sensitive G proteins in the presence of [³²P]NAD

¹ Hokkaido Research Station, National Institute of Animal Health, Hitsujigaoka-4, Toyohira, Sapporo 062-0045, Japan
² United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu-shi 501-1193, Japan
³ Obihiro University of Agriculture and Veterinary Medicine, Inada, Obihiro 080-8555, Japan
⁴ National Institute of Animal Health, Tsukuba, Ibaraki 305-0856, Japan

Salmonella enterica serotype Typhimurium (S. Typhimurium) definitive phage type (DT) 104 has become a widespread cause of human and other animal infections worldwide. The severity of clinical illness in S. Typhimurium DT104 outbreaks suggests that this strain possesses enhanced virulence. ArtA and ArtB – encoded by a prophage in S. Typhimurium DT104 – are homologues of components of pertussis toxin (PTX), including its ADP-ribosyltransferase subunit. Here, we show that exposing DT104 to mitomycin C, a DNA-damaging agent, induced production of prophage-encoded ArtA/ArtB. Pertussis-sensitive G proteins were labelled in the presence of [³²P]NAD and ArtA, and the label was released by HgCl₂, which is known to cleave cysteine-ADP-ribose bonds. ADP-dependent modification of G proteins was markedly reduced in in vitro-synthesized ArtA^6Arg-Ala and ArtA^115Glu-Ala, in which alanine was substituted for the conserved arginine at position 6 (necessary for NAD binding) and the predicted catalytic glutamate at position 115, respectively. A cellular ADP-ribosylation assay and two-dimensional electrophoresis showed that ArtA- and PTX-induced ADP-ribosylation in Chinese hamster ovary (CHO) cells occur with the same type of G proteins. Furthermore, exposing CHO cells to the ArtA/ArtB-containing culture supernatant of DT104 resulted in a clustered growth pattern, as is observed in PTX-exposed CHO cells. Hydrogen peroxide, an oxidative stressor, also induced ArtA/ArtB production, suggesting that these agents induce in vivo synthesis of ArtA/ArtB. These results, taken together, suggest that ArtA/ArtB is an active toxin similar to PTX.

Correspondence
Ikuo Uchida
ikuouchi{at}affrc.go.jp

A supplementary table of primers is available with the online version of this paper.