Salmonella enterica serotype Typhimurium DT104 ArtA-dependent modification of pertussis toxin-sensitive G proteins in the presence of [32P]NAD
| Autor: | Shinichi Hatama, Toru Kanno, Takayuki Kubota, Kiyoshi Tanaka, Ikuo Uchida, Atsushi Watanabe, Masato Akiba, Sou-ichi Makino, Ryoko Ishihara, Masato Kishima, Eiji Hata |
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| Rok vydání: | 2009 |
| Předmět: |
Salmonella typhimurium
G protein Mitomycin Molecular Sequence Data CHO Cells Biology Pertussis toxin medicine.disease_cause Microbiology Cricetulus Bacterial Proteins GTP-Binding Proteins Cricetinae medicine Animals Amino Acid Sequence ADP Ribose Transferases Virulence Toxin Chinese hamster ovary cell Hydrogen Peroxide biology.organism_classification NAD Enterobacteriaceae NAD binding Pertussis Toxin Salmonella enterica NAD+ kinase Sequence Alignment |
| Zdroj: | Microbiology (Reading, England). 155(Pt 11) |
| ISSN: | 1465-2080 |
| Popis: | Salmonella entericaserotype 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 inS.Typhimurium DT104 outbreaks suggests that this strain possesses enhanced virulence. ArtA and ArtB – encoded by a prophage inS.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 inin vitro-synthesized ArtA6Arg-Alaand ArtA115Glu-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 inducein vivosynthesis of ArtA/ArtB. These results, taken together, suggest that ArtA/ArtB is an active toxin similar to PTX. |
| Databáze: | OpenAIRE |
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