The tyrosine kinase PYK-2/RAFTK regulates natural killer (NK) cell cytotoxic response, and is translocated and activated upon specific target cell recognition and killing.
The compartmentalization of plasma membrane proteins has a key role in regulation of lymphocyte activation and development of immunity. We found that the proline-rich tyrosine kinase-2 (PYK-2/RAFTK) colocalized with the microtubule-organizing center (MTOC) at the trailing edge of migrating natural killer (NK) cells. When polyclonal NK cells bound to K562 targets, PYK-2 translocated to the area of NK-target cell interaction. The specificity of this process was assessed with NK cell clones bearing activatory or inhibitory forms of CD94/NKG2. The translocation of PYK-2, MTOC, and paxillin to the area of NK-target cell contact was regulated upon specific recognition of target cells through NK cell receptors, controlling target cell killing. Furthermore, parallel in vitro kinase assays showed that PYK-2 was activated in response to signals that specifically triggered its translocation and NK cell mediated cytotoxicity. The overexpression of both the wt and a dominant-negative mutant of PYK-2, but not ZAP-70 wt, prevented the specific translocation of the MTOC and paxillin, and blocked the cytotoxic response of NK cells. Our data indicate that subcellular compartmentalization of PYK-2 correlates with effective signal transduction. Furthermore, they also suggest an important role for PYK-2 on the assembly of the signaling complexes that regulate the cytotoxic response.
Sancho
D
D
Servicio de Inmunología, Hospital de la Princesa, Universidad Autónoma de Madrid, E-28006, Madrid, Spain.
Nieto
M
M
Llano
M
M
Rodríguez-Fernández
J L
JL
Tejedor
R
R
Avraham
S
S
Cabañas
C
C
López-Botet
M
M
Sánchez-Madrid
F
F
D000818:Animals; D015703:Antigens, CD / Q000276:immunology; D002448:Cell Adhesion; D002460:Cell Line; D002465:Cell Movement; D003598:Cytoskeletal Proteins / Q000378:metabolism; D003602:Cytotoxicity, Immunologic; D004789:Enzyme Activation; D005455:Fluorescent Antibody Technique; D051418:Focal Adhesion Kinase 2; D007694:Killer Cells, Natural / Q000276:immunology / Q000378:metabolism*; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins / Q000276:immunology; D009154:Mutation; D051920:NK Cell Lectin-Like Receptor Subfamily D; D051419:Paxillin; D010750:Phosphoproteins / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D014162:Transfection; D014616:Vaccinia virus / Q000235:genetics; D051746:ZAP-70 Protein-Tyrosine Kinase
D015703:Antigens, CD; D003598:Cytoskeletal Proteins; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins; D051920:NK Cell Lectin-Like Receptor Subfamily D; D051419:Paxillin; D010750:Phosphoproteins; D011505:Protein-Tyrosine Kinases; D051418:Focal Adhesion Kinase 2; D051746:ZAP-70 Protein-Tyrosine Kinase