Themis1, a recently described T-lineage specific protein, is essential for thymic positive and negative selection. Although Themis1 has been clearly identified as a component of the T cell antigen receptor (TCR) signalosome, its precise role in TCR signaling remains unclear. Here, we used quantitative proteomic and TCR signaling reporter mice to gain insight into Themis1 signaling function. Mass spectrometry analysis of the Themis1 interactome identified Grb2, SHP1 and Vav1 as the principal interacting partners of Themis1 in thymocytes. The dataset contains mass spectrometry results from the analysis of 6 different kind of AP-MS purifications (based on immunoprecipitation using a Themis1 antibody) starting from the following samples: - thymocytes from WT mice, non stimulated (noted WT NS) - thymocytes from WT mice, stimulated with pervanadate (noted WT P) - thymocytes from GRB2 +/- mice (with decreased expression of GRB2), non stimulated (noted GRB2 NS) - thymocytes from GRB2 +/- mice (with decreased expression of GRB2), stimulated with pervanadate (noted GRB2 P) - thymocytes from Themis1 -/- mice (knock-out for Themis1), non stimulated (noted KO NS) - thymocytes from Themis1 -/- mice (knock-out for Themis1), stimulated with pervanadate (noted KO P) Three biological replicates were prepared for these 6 different conditions (noted, 1,2,3), yielding 18 analyzed samples. Three technical nanoLC-MS runs were acquired for each sample (noted R1, R2, R3), leading to the 54 nanoLC-MS raw files contained in the dataset.