title: Role of small GTPases in Trypanosoma cruzi invasion in MDCK cell lines.
abstract: Trypanosoma cruzi can modulate a large number of host intracellular responses during its invasion. GTPases such as RhoA, Rac1 and Cdc42 are examples of molecules that could be activated at this moment and trigger changes in the pattern of F-actin cytoskeleton leading to the formation of structures like stress fibers, lamellipodium and fillopodium, respectively. Here we investigate the role of these GTPases in the cytoskeletal rearrangement of MDCK cell transfectants expressing variants of RhoA, Rac1 and Cdc42 during T. cruzi infection. The adhesion, internalization and the survival rate were determined. Rac1 mutants showed the higher adhesion and internalization indexes but the lower survival index after 48 h of infection. Confocal laser scanning microscopy showed changes in the pattern of F-actin distribution and reorganization at the site of trypomastigote invasion. These observations suggest that these GTPases act in the signaling mechanisms that affect the F-actin cytoskeleton during T. cruzi invasion.
authors.affiliation: Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho-CCS-UFRJ-Ilha do Fundão, 21940-900, Rio de Janeiro, Brazil.
authors.forename: J M F
authors.initials: JM
authors.lastname: Dutra
authors.forename: V L
authors.initials: VL
authors.lastname: Bonilha
authors.forename: W
authors.initials: W
authors.lastname: De Souza
authors.forename: T M U
authors.initials: TM
authors.lastname: Carvalho
mesh_terms: D000199:Actins / Q000032:analysis; D000818:Animals; D002448:Cell Adhesion; D002460:Cell Line; D003599:Cytoskeleton / Q000378:metabolism; D004285:Dogs; D020558:GTP Phosphohydrolases / Q000502:physiology*; D018613:Microscopy, Confocal; D014349:Trypanosoma cruzi / Q000254:growth & development*; D020764:cdc42 GTP-Binding Protein / Q000502:physiology; D020830:rac1 GTP-Binding Protein / Q000235:genetics / Q000502:physiology; D020742:rhoA GTP-Binding Protein / Q000502:physiology
chemical_list: D000199:Actins; D020558:GTP Phosphohydrolases; D020764:cdc42 GTP-Binding Protein; D020830:rac1 GTP-Binding Protein; D020742:rhoA GTP-Binding Protein