Entamoeba histolytica: a beta 1 integrin-like fibronectin receptor assembles a signaling complex similar to those of mammalian cells.
During tissue invasion, Entamoeba histolytica trophozoites interact with endothelial cells and extracellular matrix (ECM) proteins such as fibronectin (FN), collagen, and laminin. It has been demonstrated that trophozoites interact with FN through a beta1 integrin-like FN receptor (beta 1EhFNR), activating tyrosine kinases. In order to characterize the signaling process triggered by the amoebic receptor, activation, and association of tyrosine kinases and structural proteins were determined. As a result of FN binding by the beta 1EhFNR, the receptor itself, FAK, and paxillin were phosphorylated in tyrosine. Co-immunoprecipitation experiments showed that a multimolecular signaling complex was formed by the amoebic FN receptor, FAK, paxillin, and vinculin. These results strongly suggest that a signaling pathway, similar to the one used in mammalian cells, is activated when E. histolytica trophozoites adhere to FN.
Flores-Robles
Donaciano
D
Department of Experimental Pathology, CINVESTAV-IPN, Ave. I.P.N. No. 2508, Col. San Pedro Zacatenco, 07360 México, D.F., México.
Rosales
Carlos
C
Rosales-Encina
José Luis
JL
Talamás-Rohana
Patricia
P
D000818:Animals; D015153:Blotting, Western; D002448:Cell Adhesion; D003598:Cytoskeletal Proteins / Q000276:immunology / Q000502:physiology; D003720:Densitometry; D004591:Electrophoresis, Polyacrylamide Gel; D004748:Entamoeba histolytica / Q000378:metabolism / Q000502:physiology*; D005455:Fluorescent Antibody Technique; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D006801:Humans; D039081:Integrin alpha5beta1 / Q000276:immunology / Q000502:physiology*; D019012:Integrin beta1 / Q000276:immunology / Q000502:physiology*; D051419:Paxillin; D010750:Phosphoproteins / Q000276:immunology / Q000502:physiology; D010766:Phosphorylation; D011233:Precipitin Tests; D011505:Protein-Tyrosine Kinases / Q000276:immunology / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*; D016596:Vinculin / Q000276:immunology / Q000502:physiology; D019061:src-Family Kinases / Q000276:immunology / Q000502:physiology
D003598:Cytoskeletal Proteins; D039081:Integrin alpha5beta1; D019012:Integrin beta1; C496061:PXN protein, human; D051419:Paxillin; D010750:Phosphoproteins; D016596:Vinculin; D011505:Protein-Tyrosine Kinases; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496050:PTK2 protein, human; D019061:src-Family Kinases