Fig 2: Dynamics of phosphorylation and selected functional modules induced by TCR stimulation Dynamics and cluster distribution of regulated phosphotyrosines, phospho–serines, and phosphothreonines.Illustration of TCR‐regulated phosphosites within the polycomb‐repressive complex 1 (PRC1) (Ub: ubiquitination; Ac: acetylation). The corresponding log2‐transformed MS intensities measured upon TCR activation for each of the biological replicates are shown below. Box plot elements: Center line corresponds to median, box limits correspond to the first and third quartiles, and whiskers indicate variability from Q1–1.5. IQR to Q3 + 1.5 IQR.Short‐time TCR stimulation induces FOXO3 phosphorylation and NFATC2 dephosphorylation and promotes nucleus exit or entry, respectively. CD4+ T cells left unstimulated (−) or stimulated for 2 and 5 min with anti‐CD3 plus anti‐CD4 antibodies were subjected to nuclear/cytoplasmic fractionation before immunoblot analysis with antibodies specific for NFATC2 and FOXO3. Arrows indicate phosphorylation (P) and dephosphorylation (deP) forms of the transcription factors. Lamin‐B2 and GAPDH are used to control purity of nuclear and cytoplasmic extracts.t‐SNE plot highlighting phosphosites associated with the UniProt keywords “Protein biosynthesis” and “Translation regulation”. Dot transparency is scaled according to the P‐value corresponding to the local enrichment of the annotation term (hypergeometric test, see method for more detailed information).Left: Dynamics of TCR‐regulated phosphosites associated with the UniProt keywords “Protein biosynthesis” and “Translation regulation” (dots color‐coded by cluster). Right: Schematic representation of the translational initiation and elongation complexes. TCR‐regulated phosphosites are represented as small dots color‐coded by cluster.

Fig 3: Optical control of intracellular Ca2+ signal in CD8+ T cells.(a) Representative fluorescence images of Fluo-4/AM-loaded HEK293 cells during light activation. Scale bar, 100 μm. Intensity traces of mock-transfected cells (Con; n=16) and cells transiently transfected with CatCh (n=20). (b) Western blot analysis of NFAT1 phosphorylation in CatCh-expressing OT-I CD8+ T cells after light stimulation for the indicated time. (c,d) IFN-γ secretion and cytotoxicity of CatCh-expressing OT-I CD8+ T cells in the presence of G4 peptide-loaded EL-4 cells with or without light stimulation (n=3). (e) Killing of N4 peptide-loaded EL-4 cells after light stimulation of CatCh- or GFP-expressing OT-I CD8+ T cells in the presence or absence of aTregs (n=3). (f) Expression of perforin, granzyme B and CD107a on WT or Orai1-cKO CD8+ T cells after incubation with N4 peptide-loaded EL-4 cells at a 1:1 ratio for 6 h (n=3). (g) Killing of N4 peptide loaded EL-4 cells by WT or Orai1-cKO CD8+ T cells (n=6). (h) Killing of N4 peptide loaded EL-4 cells by CatCh-expressing WT or Orai1-cKO CD8+ T cells with light stimulation (463 nm) (n=3). Throughout, data are the mean±s.e.m. and were analysed by two-tailed Student's t-test.