title: Cytotoxic necrotizing factor 1 from Escherichia coli and dermonecrotic toxin from Bordetella bronchiseptica induce p21(rho)-dependent tyrosine phosphorylation of focal adhesion kinase and paxillin in Swiss 3T3 cells.
abstract: Treatment of Swiss 3T3 cells with cytotoxic necrotizing factor 1 (CNF1) from Escherichia coli and dermonecrotic toxin (DNT) from Bordetella bronchiseptica, which directly target and activate p21(rho), stimulated tyrosine phosphorylation of focal adhesion kinase (p125(fak)) and paxillin. Tyrosine phosphorylation induced by CNF1 and DNT occurred after a pronounced lag period (2 h), and was blocked by either lysosomotrophic agents or incubation at 22 degrees C. CNF1 and DNT stimulated tyrosine phosphorylation of p125(fak) and paxillin, actin stress fiber formation, and focal adhesion assembly with similar kinetics. Cytochalasin D and high concentrations of platelet-derived growth factor disrupted the actin cytoskeleton and completely inhibited CNF1 and DNT induced tyrosine phosphorylation. Microinjection of Clostridium botulinum C3 exoenzyme which ADP-ribosylates and inactivates p21(rho) function, prevented tyrosine phosphorylation of focal adhesion proteins in response to either CNF1 or DNT. In addition, our results demonstrated that CNF1 and DNT do not induce protein kinase C activation, inositol phosphate formation, and Ca2+ mobilization. Moreover, CNF1 and DNT stimulated DNA synthesis without activation of p42(mapk) and p44(mapk) providing additional evidence for a novel p21(rho)-dependent signaling pathway that leads to entry into the S phase of the cell cycle in Swiss 3T3.
authors.affiliation: Imperial Cancer Research Fund, P. O. Box 123, 44 Lincoln's Inn Fields, London WC2A 3PX, United Kingdom.
authors.forename: H M
authors.initials: HM
authors.lastname: Lacerda
authors.forename: G D
authors.initials: GD
authors.lastname: Pullinger
authors.forename: A J
authors.initials: AJ
authors.lastname: Lax
authors.forename: E
authors.initials: E
authors.lastname: Rozengurt
mesh_terms: D016475:3T3 Cells; D000199:Actins / Q000378:metabolism; D000818:Animals; D001427:Bacterial Toxins / Q000378:metabolism*; D001884:Bordetella; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D003603:Cytotoxins / Q000378:metabolism*; D004789:Enzyme Activation; D004926:Escherichia coli; D029968:Escherichia coli Proteins; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D019204:GTP-Binding Proteins / Q000378:metabolism*; D007295:Inositol Phosphates / Q000378:metabolism; D051379:Mice; D019950:Mitogen-Activated Protein Kinase 1; D051419:Paxillin; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011972:Receptor, Insulin / Q000378:metabolism*; D011503:Transglutaminases; D014443:Tyrosine / Q000378:metabolism; D010566:Virulence Factors, Bordetella; D020741:rho GTP-Binding Proteins
chemical_list: D000199:Actins; D001427:Bacterial Toxins; D015815:Cell Adhesion Molecules; D003598:Cytoskeletal Proteins; D003603:Cytotoxins; D029968:Escherichia coli Proteins; D007295:Inositol Phosphates; D051419:Paxillin; D010750:Phosphoproteins; C496062:Pxn protein, mouse; D010566:Virulence Factors, Bordetella; C060969:dermonecrotic toxin, Bordetella; C060296:cytotoxic necrotizing factor type 1; D014443:Tyrosine; D011503:Transglutaminases; D011505:Protein-Tyrosine Kinases; D011972:Receptor, Insulin; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496051:Ptk2 protein, mouse; D011493:Protein Kinase C; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1; D019204:GTP-Binding Proteins; D020741:rho GTP-Binding Proteins