The adapter proteins ADAP and Nck cooperate in T cell adhesion.
Nck adapter proteins link receptor and receptor-associated tyrosine kinases with proteins implicated in the regulation of the actin cytoskeleton. Nck is involved in a multitude of receptor-initiated signaling pathways and its physiological role thus covers aspects of tissue development and homeostasis, malignant transformation/invasiveness of tumour cells and also immune cell function. In T cells, changes of cell polarity and morphology associated with cellular activation and effector function crucially rely on the T cell receptor-mediated recruitment and activation of different actin-regulatory proteins to orchestrate and drive cytoskeletal reorganization at the immunological synapse. In a former approach to determine the interactome of Nck in human T cells, we identified the adapter protein ADAP as a Nck-interacting protein. This adhesion and degranulation-promoting adapter protein had already been implicated in the inside-out activation of integrins. Employing co-immunoprecipitations, we demonstrate that both Nck family members Nck1 and Nck2 coprecipitate with ADAP. Specifically, Nck interacts via its Src homology 2 domain with phosphorylated tyrosine Y595DDV and Y651DDV sites of ADAP. Moreover, we show that endogenous ADAP is phosphorylated in primary human T cell blasts and thus associates with Nck. At the functional level, ADAP and Nck adapter proteins cooperatively facilitate T cell adhesion to the LFA-1 ligand ICAM-1. Our data indicate that the ADAP/Nck complex might provide a means to link integrin activation with the actin cytoskeleton.
Institute of Immunology, University Hospital Schleswig-Holstein, Campus Kiel, Arnold-Heller-Str. 3, Bldg 17, D-24105 Kiel, Germany. Electronic address: lettau@immunologie.uni-kiel.de.
Marcus
M
Lettau
Institute of Molecular and Clinical Immunology, Otto-von-Guericke University, Leipziger Str. 44, D-39120 Magdeburg, Germany. Electronic address: stefanie.kliche@med.ovgu.de.
Stefanie
S
Kliche
Institute of Immunology, University Hospital Schleswig-Holstein, Campus Kiel, Arnold-Heller-Str. 3, Bldg 17, D-24105 Kiel, Germany. Electronic address: Dietrich.Kabelitz@uksh.de.
Dieter
D
Kabelitz
Institute of Immunology, University Hospital Schleswig-Holstein, Campus Kiel, Arnold-Heller-Str. 3, Bldg 17, D-24105 Kiel, Germany. Electronic address: Ottmar.Janssen@uksh.de.
Ottmar
O
Janssen
D008841:Actin Cytoskeleton / Q000276:immunology; D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism*; D002448:Cell Adhesion / Q000276:immunology; D002460:Cell Line; D004789:Enzyme Activation / Q000276:immunology; D057809:HEK293 Cells; D006801:Humans; D016023:Integrins / Q000276:immunology; D018799:Intercellular Adhesion Molecule-1 / Q000276:immunology; D016169:Lymphocyte Function-Associated Antigen-1 / Q000276:immunology; D015513:Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D017434:Protein Structure, Tertiary; D034622:RNA Interference; D034741:RNA, Small Interfering; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology*
D048868:Adaptor Proteins, Signal Transducing; C106957:FYB1 protein, human; D016023:Integrins; D016169:Lymphocyte Function-Associated Antigen-1; C485544:NCK2 protein, human; C078332:Nck protein; D015513:Oncogene Proteins; D034741:RNA, Small Interfering; D018799:Intercellular Adhesion Molecule-1
ADAP; Adhesion; ICAM-1; LFA-1; Nck; T cells