In vitro GAP activity towards RhoA, Rac1 and Cdc42 is not a prerequisite for YopE induced HeLa cell cytotoxicity
| Autor: | Bengt Hallberg, Maxim V. Telepnev, Margareta Aili, Hans Wolf-Watz, Roland Rosqvist |
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| Rok vydání: | 2003 |
| Předmět: |
Models
Molecular rac1 GTP-Binding Protein rho GTP-Binding Proteins RHOA GTPase-activating protein Cell Bacterial Toxins Molecular Sequence Data CDC42 Microbiology HeLa medicine Cytotoxic T cell Humans Amino Acid Sequence Cytotoxicity cdc42 GTP-Binding Protein Actin biology Cytotoxins GTPase-Activating Proteins biology.organism_classification Cytotoxicity Tests Immunologic Recombinant Proteins Cell biology Infectious Diseases medicine.anatomical_structure Mutation biology.protein rhoA GTP-Binding Protein Sequence Alignment Gene Deletion Bacterial Outer Membrane Proteins HeLa Cells |
| Zdroj: | Microbial pathogenesis. 34(6) |
| ISSN: | 0882-4010 |
| Popis: | The YopE cytotoxin of Yersinia is an essential virulence determinant that is translocated into the eukaryotic target cell via a plasmid-encoded type III secretion system. YopE possess a GTPase activating protein activity that in vitro has been shown to down regulate RhoA, Rac1, and Cdc42. Translocated YopE induces de-polymerisation of the actin microfilament structure in the eukaryotic cell which results in a rounding up of infected cells described as a cytotoxic effect. Here, we have investigated the importance of different regions of YopE for induction of cytotoxicity and in vitro GAP activity. Sequential removal of the N- and C-terminus of YopE identified the region between amino acids 90 and 215 to be necessary for induction of cytotoxicity. Internal deletions containing the essential arginine at position 144 resulted in a total loss of cytotoxic response. In-frame deletions flanking the arginine finger defined a region important for the cytotoxic effect to amino acids 166-183. Four triple-alanine substitution mutants in this region, YopE166-8A, 169-71A, 175-7A and 178-80A were still able to induce cytotoxicity on HeLa cells although they did not show any in vitro GAP activity towards RhoA, Rac1 or Cdc42. A substitution mutant in position 206-8A showed the same phenotype, ability to induce cytotoxic response but no in vitro GAP activity. We speculate that YopE may have additional unidentified targets within the eukaryotic cell. |
| Databáze: | OpenAIRE |
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