title: Themis1 enhances T cell receptor signaling during thymocyte development by promoting Vav1 activity and Grb2 stability.
abstract: The T cell signaling protein Themis1 is essential for the positive and negative selection of thymocytes in the thymus. Although the developmental defect that results from the loss of Themis1 suggests that it enhances T cell receptor (TCR) signaling, Themis1 also recruits Src homology 2 domain-containing phosphatase-1 (SHP-1) to the vicinity of TCR signaling complexes, suggesting that it has an inhibitory role in TCR signaling. We used TCR signaling reporter mice and quantitative proteomics to explore the role of Themis1 in developing T cells. We found that Themis1 acted mostly as a positive regulator of TCR signaling in vivo when receptors were activated by positively selecting ligands. Proteomic analysis of the Themis1 interactome identified SHP-1, the TCR-associated adaptor protein Grb2, and the guanine nucleotide exchange factor Vav1 as the principal interacting partners of Themis1 in isolated mouse thymocytes. Analysis of TCR signaling in Themis1-deficient and Themis1-overexpressing mouse thymocytes demonstrated that Themis1 promoted Vav1 activity both in vitro and in vivo. The reduced activity of Vav1 and the impaired T cell development in Themis1(-/-) mice were due in part to increased degradation of Grb2, which suggests that Themis1 is required to maintain the steady-state abundance of Grb2 in thymocytes. Together, these data suggest that Themis1 acts as a positive regulator of TCR signaling in developing T cells, and identify a mechanism by which Themis1 regulates thymic selection.
authors.affiliation: Section on Cellular and Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Zvezdova
authors.affiliation: Centre de Physiopathologie de Toulouse Purpan, Toulouse F-31300, France. Institut National de la Santé et de la Recherche Médicale, U1043, Toulouse F-31300, France. Centre National de la Recherche Scientifique, U5282, Toulouse F-31300, France. Université de Toulouse, Université Paul Sabatier, Toulouse F-31300, France.
authors.forename: Judith
authors.initials: J
authors.lastname: Mikolajczak
authors.affiliation: Centre de Physiopathologie de Toulouse Purpan, Toulouse F-31300, France. Institut National de la Santé et de la Recherche Médicale, U1043, Toulouse F-31300, France. Centre National de la Recherche Scientifique, U5282, Toulouse F-31300, France. Université de Toulouse, Université Paul Sabatier, Toulouse F-31300, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Garreau
authors.affiliation: Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse F-31077, France.
authors.forename: Marlène
authors.initials: M
authors.lastname: Marcellin
authors.affiliation: Centre de Physiopathologie de Toulouse Purpan, Toulouse F-31300, France. Institut National de la Santé et de la Recherche Médicale, U1043, Toulouse F-31300, France. Centre National de la Recherche Scientifique, U5282, Toulouse F-31300, France. Université de Toulouse, Université Paul Sabatier, Toulouse F-31300, France.
authors.forename: Lise
authors.initials: L
authors.lastname: Rigal
authors.affiliation: Section on Cellular and Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Jan
authors.initials: J
authors.lastname: Lee
authors.affiliation: Section on Cellular and Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Seeyoung
authors.initials: S
authors.lastname: Choi
authors.affiliation: Centre de Physiopathologie de Toulouse Purpan, Toulouse F-31300, France. Institut National de la Santé et de la Recherche Médicale, U1043, Toulouse F-31300, France. Centre National de la Recherche Scientifique, U5282, Toulouse F-31300, France. Université de Toulouse, Université Paul Sabatier, Toulouse F-31300, France.
authors.forename: Gaëtan
authors.initials: G
authors.lastname: Blaize
authors.affiliation: Centre de Physiopathologie de Toulouse Purpan, Toulouse F-31300, France. Institut National de la Santé et de la Recherche Médicale, U1043, Toulouse F-31300, France. Centre National de la Recherche Scientifique, U5282, Toulouse F-31300, France. Université de Toulouse, Université Paul Sabatier, Toulouse F-31300, France.
authors.forename: Jérémy
authors.initials: J
authors.lastname: Argenty
authors.affiliation: Centre de Physiopathologie de Toulouse Purpan, Toulouse F-31300, France. Institut National de la Santé et de la Recherche Médicale, U1043, Toulouse F-31300, France. Centre National de la Recherche Scientifique, U5282, Toulouse F-31300, France. Université de Toulouse, Université Paul Sabatier, Toulouse F-31300, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Familiades
authors.affiliation: Section on Cellular and Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Liqi
authors.initials: L
authors.lastname: Li
authors.affiliation: Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse F-31077, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Gonzalez de Peredo
authors.affiliation: Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse F-31077, France.
authors.forename: Odile
authors.initials: O
authors.lastname: Burlet-Schiltz
authors.affiliation: Section on Cellular and Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Paul E
authors.initials: PE
authors.lastname: Love
authors.affiliation: Centre de Physiopathologie de Toulouse Purpan, Toulouse F-31300, France. Institut National de la Santé et de la Recherche Médicale, U1043, Toulouse F-31300, France. Centre National de la Recherche Scientifique, U5282, Toulouse F-31300, France. Université de Toulouse, Université Paul Sabatier, Toulouse F-31300, France. renaud.lesourne@inserm.fr.
authors.forename: Renaud
authors.initials: R
authors.lastname: Lesourne
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D051380:GRB2 Adaptor Protein / Q000378:metabolism*; D036341:Intercellular Signaling Peptides and Proteins; D008213:Lymphocyte Activation; D051379:Mice; D008822:Mice, Transgenic; D009479:Neuropeptides / Q000378:metabolism; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6 / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*; D040901:Proteomics / Q000379:methods; D051567:Proto-Oncogene Proteins c-vav / Q000378:metabolism*; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism*; D015398:Signal Transduction; D060168:Thymocytes / Q000166:cytology*; D019076:Transgenes; D020830:rac1 GTP-Binding Protein / Q000378:metabolism
chemical_list: D051380:GRB2 Adaptor Protein; C495949:Grb2 protein, mouse; D036341:Intercellular Signaling Peptides and Proteins; D009479:Neuropeptides; D011506:Proteins; D051567:Proto-Oncogene Proteins c-vav; C484602:Rac1 protein, mouse; D011948:Receptors, Antigen, T-Cell; C496619:Vav1 protein, mouse; C544192:themis protein, mouse; D010744:Phosphoric Monoester Hydrolases; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6; C509248:Ptpn6 protein, mouse; D020830:rac1 GTP-Binding Protein