title: The adapter protein Nck: role of individual SH3 and SH2 binding modules for protein interactions in T lymphocytes.
abstract: Nck is a ubiquitously expressed, primarily cytosolic adapter protein consisting of one SH2 domain and three SH3 domains. It links receptor and nonreceptor tyrosine kinases to actin cytoskeleton reorganizing proteins. In T lymphocytes, Nck is a crucial component of signaling pathways for T cell activation and effector function. It recruits actin remodeling proteins to T cell receptor (TCR)-associated activation clusters and thereby initiates changes in cell polarity and morphology. Moreover, Nck is crucial for the TCR-induced mobilization of secretory vesicles to the cytotoxic immunological synapse. To identify the interactome of Nck in human T cells, we performed a systematic screen for interaction partners in untreated or pervanadate-treated cells. We used GST fusion proteins containing full length Nck, the combined SH3 domains or the individual SH3 and SH2 domains to precipitate putative Nck interactors from cellular lysates. Protein bands were excised from gels, processed by tryptic in-gel digestion and analyzed by mass spectrometry. Using this approach, we confirmed previously established interactions (e.g., with Slp76, CD3 epsilon, WASP, and WIPF1) and identified several novel putative Nck-binding proteins. We subsequently verified the SH2 domain binding to the actin-binding protein HIP55 and to FYB/ADAP, and the SH3-mediated binding to the nuclear proteins SFPQ/NONO. Using laser scanning microscopy, we provide new evidence for a nuclear localization of Nck in human T cells. Our data highlight the fundamental role of Nck in the TCR-to-cytoskeleton crosstalk and point to yet unknown nuclear functions of Nck also in T lymphocytes.
authors.affiliation: Molecular Immunology, Institute for Immunology, Christian-Albrechts University, D-24105 Kiel, Germany. lettau@immunologie.uni-kiel.de
authors.forename: Marcus
authors.initials: M
authors.lastname: Lettau
authors.forename: Jennifer
authors.initials: J
authors.lastname: Pieper
authors.forename: Alyn
authors.initials: A
authors.lastname: Gerneth
authors.forename: Beate
authors.initials: B
authors.lastname: Lengl-Janssen
authors.forename: Matthias
authors.initials: M
authors.lastname: Voss
authors.forename: Andreas
authors.initials: A
authors.lastname: Linkermann
authors.forename: Hendrik
authors.initials: H
authors.lastname: Schmidt
authors.forename: Christoph
authors.initials: C
authors.lastname: Gelhaus
authors.forename: Matthias
authors.initials: M
authors.lastname: Leippe
authors.forename: Dieter
authors.initials: D
authors.lastname: Kabelitz
authors.forename: Ottmar
authors.initials: O
authors.lastname: Janssen
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D006801:Humans; D019169:Jurkat Cells; D018613:Microscopy, Confocal; D015513:Oncogene Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D013601:T-Lymphocytes / Q000378:metabolism*; D018909:src Homology Domains
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C078332:Nck protein; D015513:Oncogene Proteins; D011948:Receptors, Antigen, T-Cell