Deamidation of Cdc42 and Rac by Escherichia coli cytotoxic necrotizing factor 1: activation of c-Jun N-terminal kinase in HeLa cells
1999 (English)In: Infection and Immunity, ISSN 0019-9567, E-ISSN 1098-5522, Vol. 67, no 2, 496-503 p.Article in journal (Refereed) Published
Recently, Escherichia coli cytotoxic necrotizing factor 1 (CNF1) was shown to activate the low-molecular-mass GTPase RhoA by deamidation of Gln63, thereby inhibiting intrinsic and GTPase-activating protein (GAP)-stimulated GTPase activities (G. Schmidt, P. Sehr, M. Wilm, J. Selzer, M. Mann, and K. Aktories, Nature 387:725-729, 1997; G. Flatau, E. Lemichez, M. Gauthier, P. Chardin, S. Paris, C. Fiorentini, and P. Boquet, Nature 387:729-733, 1997). Here we report that in addition to RhoA, Cdc42 and Rac also are targets for CNF1 in vitro and in intact cells. Treatment of HeLa cells with CNF1 induced a transient formation of microspikes and formation of membrane ruffles. CNF1 caused a transient 10- to 50-fold increase in the activity of the c-Jun N-terminal kinase. Tryptic peptides of Cdc42 obtained from CNF1-treated cells by immunoprecipitation exhibited an increase in mass of 1 Da compared to control peptides, indicating the deamidation of glutamine 61 by the toxin. The same increase in mass was observed with the respective peptides obtained from CNF1-modified recombinant Cdc42 and Rac1. Modification of recombinant Cdc42 and Rac1 by CNF1 inhibited intrinsic and GAP-stimulated GTPase activities and retarded binding of 2'(3')-O-(N-methylanthraniloyl)GDP. The data suggest that recombinant as well as cellular Cdc42 and Rac are substrates for CNF1.
Place, publisher, year, edition, pages
American Society for Microbiology , 1999. Vol. 67, no 2, 496-503 p.
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-99622PubMedID: 9916051OAI: oai:DiVA.org:liu-99622DiVA: diva2:657395