Enzymatic actions of Pasteurella multocida toxin detected by monoclonal antibodies recognizing the deamidated subunit of the heterotrimeric GTPase Gq

来自 Wiley

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作者：

S Kamitani，S Ao，H Toshima，T Tachibana，M Hashimoto，K Kitadokoro，A Fukui-Miyazaki，HA And，Y Horiguchi

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摘要：

Pasteurella multocida toxin (PMT) is a virulence factor responsible for the pathogenesis of some Pasteurellosis. PMT exerts its toxic effects through the activation of heterotrimeric GTPase (Gq, G12/13 and Gi)-dependent pathways, by deamidating a glutamine residue in the subunit of these GTPases. However, the enzymatic characteristics of PMT are yet to be analyzed in detail because the deamidation has only been observed in cell-based assays. In the present study, we developed rat monoclonal antibodies, specifically recognizing the deamidated Gq, to detect the actions of PMT by immunological techniques such as western blotting. Using the monoclonal antibodies, we found that the toxin deamidated Gq only under reducing conditions. The C-terminal region of PMT, C-PMT, was more active than the full-length PMT. The C3 domain possessing the enzyme core catalyzed the deamidation in vitro without any other domains. These results not only support previous observations on toxicity, but also provide insights into the enzymatic nature of PMT. In addition, we present several lines of evidence that G11, as well as Gq, could be a substrate for PMT.

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关键词：

bacterial toxin deamidation GTPase heterotrimeric in vitro assay monoclonal antibody Pasteurella multocida toxin

DOI：

10.1111/j.1742-4658.2011.08197.x

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年份：

2011