Threonine phosphorylation at JM regions influences the monomer–dimer equilibrium of EGF-bound EGFR.

(A-D) Time traces of the diffusion coefficient of the EGFR with JM region threonine residue mutations; phosphodeficient mutant, EGFR^T654/669A (A), three phosphomimic mutants, EGFR^T654/669E (B), EGFR^T654E (C), and EGFR^T669E (D). (E) EGF (Alexa647-labeled, 0.17 μM; magenta) binding to EGFR^T654/669E (green) expressing cell. The right panel shows the merged image. Scale bars represent 10 μm.