biostudies-literatureMcAffee DBU.S. Department of Health & Human Services | NIH | National Institute of Allergy and Infectious DiseasesNIAID NIH HHSNovo Nordisk Fonden7446https://www.ebi.ac.uk/biostudies/studies/S-EPMC9718779biostudies-literatureUnknown13(1)LAT assembly into a two-dimensional protein condensate is a prominent feature of antigen discrimination by T cells. Here, we use single-molecule imaging techniques to resolve the spatial position and temporal duration of each pMHC:TCR molecular binding event while simultaneously monitoring LAT condensation at the membrane. An individual binding event is sufficient to trigger a LAT condensate, which is self-limiting, and neither its size nor lifetime is correlated with the duration of the originating pMHC:TCR binding event. Only the probability of the LAT condensate forming is related to the pMHC:TCR binding dwell time. LAT condenses abruptly, but after an extended delay from the originating binding event. A LAT mutation that facilitates phosphorylation at the PLC-γ1 recruitment site shortens the delay time to LAT condensation and alters T cell antigen specificity. These results identify a function for the LAT protein condensation phase transition in setting antigen discrimination thresholds in T cells.Nature communicationsDiscrete LAT condensates encode antigen information from single pMHC:TCR binding events.PMC9718779NNF17OC0028176AI091580P01 AI091580Low-Nam STKim SMcAffee DBWilhelm KBO'Dair MKLin JJMorita SGroves JTfalseDiscrete LAT condensates encode antigen information from single pMHC:TCR binding events.LAT assembly into a two-dimensional protein condensate is a prominent feature of antigen discrimination by T cells. Here, we use single-molecule imaging techniques to resolve the spatial position and temporal duration of each pMHC:TCR molecular binding event while simultaneously monitoring LAT condensation at the membrane. An individual binding event is sufficient to trigger a LAT condensate, which is self-limiting, and neither its size nor lifetime is correlated with the duration of the originating pMHC:TCR binding event. Only the probability of the LAT condensate forming is related to the pMHC:TCR binding dwell time. LAT condenses abruptly, but after an extended delay from the originating binding event. A LAT mutation that facilitates phosphorylation at the PLC-γ1 recruitment site shortens the delay time to LAT condensation and alters T cell antigen specificity. These results identify a function for the LAT protein condensation phase transition in setting antigen discrimination thresholds in T cells.2022-01-01T00:00:00Z2022 Dec2026-06-03T13:21:34.73Z2025-04-05T19:07:15.197ZS-EPMC97187793646064010.1038/s41467-022-35093-9