Fig. 5.

Phosphorylation status of signaling proteins at the IS. Purified CD4⁺ T cells and anti-CD3 hybridomas were coincubated, fixed, permeablized, and labeled with Abs specific to either phospho-LAT or phospho-PLCγ-1, as described in the Methods. (A) Representative image of LAT phosphorylation at the IS in fat-1 cells. Image contrast was adjusted. Scale bar, 5 μm. (B) Protein activation was assessed by percent patching (n=37-59 cells from 3-4 mice per genotype for each protein).