Requirements for Vav Guanine Nucleotide Exchange Factors and Rho GTPases in FcγR- and Complement-Mediated Phagocytosis
| Autor: | Michael Glogauer, M. Angelica Martinez Gakidis, Joan S. Brugge, Julie L. Wilsbacher, Amy B. Hall, Wojciech Swat, Sizhen Gao |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
rac1 GTP-Binding Protein
rho GTP-Binding Proteins VAV3 VAV1 Phagocytosis Immunology Macrophage-1 Antigen RAC1 Complement receptor Biology Mice 03 medical and health sciences 0302 clinical medicine Animals Guanine Nucleotide Exchange Factors Immunology and Allergy Proto-Oncogene Proteins c-vav 030304 developmental biology Phagosome 0303 health sciences Receptors IgG Actins rac GTP-Binding Proteins Cell biology Infectious Diseases 030220 oncology & carcinogenesis Microscopy Electron Scanning Guanine nucleotide exchange factor Signal transduction Signal Transduction |
| Zdroj: | Immunity. 24:305-316 |
| ISSN: | 1074-7613 |
| DOI: | 10.1016/j.immuni.2006.02.005 |
| Popis: | Vav guanine nucleotide exchange factors (GEFs) have been implicated in cell adhesion by integrin and immune response receptors through the regulation of Rho GTPases. Here, we examine the role of Vav and Rho GTPases in phagocytosis by using primary murine macrophages. The genetic deletion of Rac1 and Rac2 prevents phagocytosis mediated by integrin and Fcgamma receptors (FcgammaR), whereas the genetic deletion of Vav1 and Vav3 only prevents integrin-mediated phagocytosis through the complement receptor alpha(M)beta(2). In addition, a Rac1/2 or Vav1/3 deficiency blocks Arp2/3 recruitment and actin polymerization at the complement-induced phagosome, indicating that these proteins regulate early steps in phagocytosis. Moreover, constitutively active Rac is able to rescue actin polymerization and complement-mediated phagocytosis in Vav-deficient macrophages. These studies indicate that Rac is critical for complement- and FcgammaR-mediated phagocytosis. In contrast, Vav is specifically required for complement-mediated phagocytosis, suggesting that Rac is regulated by GEFs other than Vav downstream of the FcgammaR. |
| Databáze: | OpenAIRE |
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