title: GRB2-mediated recruitment of THEMIS to LAT is essential for thymocyte development.
abstract: Thymocyte-expressed molecule involved in selection (THEMIS) is a recently identified regulator of thymocyte positive selection. THEMIS's mechanism of action is unknown, and whether it has a role in TCR-proximal signaling is controversial. In this article, we show that THEMIS and the adapter molecule growth factor receptor-bound protein 2 (GRB2) associate constitutively through binding of a conserved PxRPxK motif within the proline-rich region 1 of THEMIS to the C-terminal SH3-domain of GRB2. This association is indispensable for THEMIS recruitment to the immunological synapse via the transmembrane adapter linker for activation of T cells (LAT) and for THEMIS phosphorylation by Lck and ZAP-70. Two major sites of tyrosine phosphorylation were mapped to a YY-motif close to proline-rich region 1. The YY-motif was crucial for GRB2 binding, suggesting that this region of THEMIS might control local phosphorylation-dependent conformational changes important for THEMIS function. Finally, THEMIS binding to GRB2 was required for thymocyte development. Our data firmly assign THEMIS to the TCR-proximal signaling cascade as a participant in the LAT signalosome and suggest that the THEMIS-GRB2 complex might be involved in shaping the nature of Ras signaling, thereby governing thymic selection.
authors: Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom.
authors: Wolfgang
authors: W
authors: Paster
authors: Claudia
authors: C
authors: Brockmeyer
authors: Guo
authors: G
authors: Fu
authors: Philip C
authors: PC
authors: Simister
authors: Ben
authors: B
authors: de Wet
authors: Ana
authors: A
authors: Martinez-Riaño
authors: John A H
authors: JA
authors: Hoerter
authors: Stephan M
authors: SM
authors: Feller
authors: Christoph
authors: C
authors: Wülfing
authors: Nicholas R J
authors: NR
authors: Gascoigne
authors: Oreste
authors: O
authors: Acuto
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D000595:Amino Acid Sequence; D015815:Cell Adhesion Molecules / Q000378:metabolism; D002460:Cell Line; D051380:GRB2 Adaptor Protein / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D054992:Immunological Synapses / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000737:chemistry / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D000075983:Nectins; D010766:Phosphorylation; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D016415:Sequence Alignment; D060168:Thymocytes / Q000378:metabolism*; D051746:ZAP-70 Protein-Tyrosine Kinase / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D015815:Cell Adhesion Molecules; D051380:GRB2 Adaptor Protein; D047908:Intracellular Signaling Peptides and Proteins; C110810:LAT protein, human; D008565:Membrane Proteins; D000075983:Nectins; C557796:thymocyte-expressed molecule involved in selection, human; D051746:ZAP-70 Protein-Tyrosine Kinase