Cross-phosphorylation of EGFR establishes phosphorylation gradients.
(A) Lifetime of the mobility states, after selecting Cy3-SNAP-EGFR particles that colocalized with EGFP-PTB (B) Quantification of the distribution of confined particles around immobile points (Kconfined) calculated for all particles in unstimulated and stimulated cells and for particles that colocalized with PTB after stimulation with EGF. The dashed line represents the Kconfined function in unstimulated cells after randomization of the particle locations. n = 43 cells per time point. *P < 0.05, **P < 0.01, ***P < 0.001, t tests comparing the Kconfined values of particles that colocalize with PTB after 10 minutes (red line) with the corresponding Kconfined values of all particles before stimulation (continuous black line). Error bars denote SEM.
