title: WASp family verprolin-homologous protein-2 (WAVE2) and Wiskott-Aldrich syndrome protein (WASp) engage in distinct downstream signaling interactions at the T cell antigen receptor site.
abstract: T cell antigen receptor (TCR) engagement has been shown to activate pathways leading to actin cytoskeletal polymerization and reorganization, which are essential for lymphocyte activation and function. Several actin regulatory proteins were implicated in regulating the actin machinery, such as members of the Wiskott-Aldrich syndrome protein (WASp) family. These include WASp and the WASp family verprolin-homologous protein-2 (WAVE2). Although WASp and WAVE2 share several structural features, the precise regulatory mechanisms and potential redundancy between them have not been fully characterized. Specifically, unlike WASp, the dynamic molecular interactions that regulate WAVE2 recruitment to the cell membrane and specifically to the TCR signaling complex are largely unknown. Here, we identify the molecular mechanism that controls the recruitment of WAVE2 in comparison with WASp. Using fluorescence resonance energy transfer (FRET) and novel triple-color FRET (3FRET) technology, we demonstrate how WAVE2 signaling complexes are dynamically regulated during lymphocyte activation in vivo. We show that, similar to WASp, WAVE2 recruitment to the TCR site depends on protein-tyrosine kinase, ZAP-70, and the adaptors LAT, SLP-76, and Nck. However, in contrast to WASp, WAVE2 leaves this signaling complex and migrates peripherally together with vinculin to the membrane leading edge. Our experiments demonstrate that WASp and WAVE2 differ in their dynamics and their associated proteins. Thus, this study reveals the differential mechanisms regulating the function of these cytoskeletal proteins.
authors.affiliation: From the Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel.
authors.forename: Maor H
authors.initials: MH
authors.lastname: Pauker
authors.affiliation: From the Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel.
authors.forename: Barak
authors.initials: B
authors.lastname: Reicher
authors.affiliation: From the Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel.
authors.forename: Noah
authors.initials: N
authors.lastname: Joseph
authors.affiliation: From the Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel.
authors.forename: Inbal
authors.initials: I
authors.lastname: Wortzel
authors.affiliation: From the Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel.
authors.forename: Shlomi
authors.initials: S
authors.lastname: Jakubowicz
authors.affiliation: From the Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel.
authors.forename: Elad
authors.initials: E
authors.lastname: Noy
authors.affiliation: From the Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel.
authors.forename: Orly
authors.initials: O
authors.lastname: Perl
authors.affiliation: From the Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel Mira.Barda-Saad@biu.ac.il.
authors.forename: Mira
authors.initials: M
authors.lastname: Barda-Saad
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D006801:Humans; D054992:Immunological Synapses / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D015513:Oncogene Proteins / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism; D011485:Protein Binding; D021381:Protein Transport; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism*; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D051316:Wiskott-Aldrich Syndrome Protein / Q000378:metabolism*; D051300:Wiskott-Aldrich Syndrome Protein Family / Q000378:metabolism*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C110810:LAT protein, human; D008565:Membrane Proteins; C078332:Nck protein; D015513:Oncogene Proteins; D010750:Phosphoproteins; D011948:Receptors, Antigen, T-Cell; C092947:SLP-76 signal Transducing adaptor proteins; D051316:Wiskott-Aldrich Syndrome Protein; D051300:Wiskott-Aldrich Syndrome Protein Family
keywords: Actin; Adaptor Protein; Cytoskeleton; Lymphocyte; Molecular Dynamics; T Cell Receptor (TCR); T Cell Signaling; WASp; WAVE2