Fig. 4. LAT condensation occurs after an extended delay.

Primary mouse T cells expressing different constructs were deposited onto bilayers with 0.1–0.2 molecules μm⁻² of MCC(Atto647) pMHC. For the histograms, linearly increasing bin widths were used to improve the sampling rate of rare long-delay events. Scale bars are 1 μm. a TIRF images of LAT-eGFP condensation within T cells in response to a single pMHC:TCR binding event. LAT condensation occurs near the binding event after a long delay, ${\tau }_{delay}^{LAT}$, measured relative to the moment of pMHC:TCR binding. b Histogram of an ensemble LAT condensate delay times (115 binding events, from 18 cells across 4 mice). c TIRF images of LAT-mScarleti and mNeonGreen-GRB2 clustering within T cells in response to a single pMHC:TCR binding event. Delay times of LAT clustering, ${\tau }_{delay}^{LAT}$, and GRB2 clustering, ${\tau }_{delay}^{GRB2}$, relative to binding were equivalent within the resolution of this experiment (<2 s). d Histogram of an ensemble GRB2 clustering delay times from T cells expressing only mNeonGreen-GRB2 (75 binding events, from 21 cells across 4 mice). e TIRF images of LAT(G135D)-eGFP condensation within T cells in response to a single pMHC:TCR binding event. f Histogram of an ensemble of delay times between pMHC:TCR binding and LAT(G135D) condensation (102 binding events, from 17 cells across 3 mice). Related data are in Supplementary Fig. 4. Source data are provided as a Source data file.