Proline-rich tyrosine kinase 2 and Rac activation by chemokine and integrin receptors controls NK cell transendothelial migration.
Protein tyrosine kinase activation is an important requisite for leukocyte migration. Herein we demonstrate that NK cell binding to endothelium activates proline-rich tyrosine kinase 2 (Pyk-2) and the small GTP binding protein Rac that are coupled to integrin and chemokine receptors. Chemokine-mediated, but not integrin-mediated, Pyk-2 and Rac activation was sensitive to pretreatment of NK cells with pertussis toxin, a pharmacological inhibitor of G(i) protein-coupled receptors. Both Pyk-2 and Rac are functionally involved in chemokine-induced NK cell migration through endothelium or ICAM-1 or VCAM-1 adhesive proteins, as shown by the use of recombinant vaccinia viruses encoding dominant negative mutants of Pyk-2 and Rac. Moreover, we found that Pyk-2 is associated with the Rac guanine nucleotide exchange factor Vav, which undergoes tyrosine phosphorylation upon integrin triggering. Finally, we provide direct evidence for the involvement of Pyk-2 in the control of both chemokine- and integrin-mediated Rac activation. Collectively, our results indicate that Pyk-2 acts as a receptor-proximal link between integrin and chemokine receptor signaling, and the Pyk-2/Rac pathway plays a pivotal role in the control of NK cell transendothelial migration.
Gismondi
Angela
A
Department of Experimental Medicine and Pathology, Istituto Pasteur-Fondazione Cenci Bolognetti, University of Rome La Sapienza, Rome, Italy. angela.gismondi@uniroma1.it
Jacobelli
Jordan
J
Strippoli
Raffaele
R
Mainiero
Fabrizio
F
Soriani
Alessandra
A
Cifaldi
Loredana
L
Piccoli
Mario
M
Frati
Luigi
L
Santoni
Angela
A
D002448:Cell Adhesion / Q000276:immunology; D002460:Cell Line; D002461:Cell Line, Transformed; D002465:Cell Movement / Q000276:immunology*; D002478:Cells, Cultured; D004727:Endothelium / Q000166:cytology / Q000201:enzymology / Q000276:immunology* / Q000378:metabolism; D051418:Focal Adhesion Kinase 2; D006801:Humans; D039041:Integrin alpha4beta1 / Q000502:physiology; D016023:Integrins / Q000378:metabolism / Q000502:physiology*; D018799:Intercellular Adhesion Molecule-1 / Q000494:pharmacology; D007694:Killer Cells, Natural / Q000166:cytology / Q000201:enzymology / Q000276:immunology* / Q000378:metabolism; D008213:Lymphocyte Activation / Q000276:immunology; D016169:Lymphocyte Function-Associated Antigen-1 / Q000502:physiology; D010766:Phosphorylation; D011392:Proline / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000502:physiology*; D019707:Receptors, Chemokine / Q000502:physiology*; D014443:Tyrosine / Q000378:metabolism; D019010:Vascular Cell Adhesion Molecule-1 / Q000494:pharmacology; D020744:rac GTP-Binding Proteins / Q000378:metabolism* / Q000502:physiology
D039041:Integrin alpha4beta1; D016023:Integrins; D016169:Lymphocyte Function-Associated Antigen-1; D019707:Receptors, Chemokine; D019010:Vascular Cell Adhesion Molecule-1; D018799:Intercellular Adhesion Molecule-1; D014443:Tyrosine; D011392:Proline; D011505:Protein-Tyrosine Kinases; D051418:Focal Adhesion Kinase 2; D020744:rac GTP-Binding Proteins