Figure 1

In vitro binding assay using synthetic IL-4Rα peptides (amino acids 545–558 = Q551/R551; control amino acids = 726–784). To assess the binding of cellular proteins to the peptides, 20 μl of peptide-conjugated Affigel beads were incubated with lysates from IL-13-activated cells (3 × 10⁷ cells). The peptide-associated SHP-2 were analyzed by immunoblotting with specific antibodies (monoclonal anti SHP-2; Transduction Laboratories) and developed using a chemiluminescence kit (ECL; Amersham, Germany). Cells were (1): wildtype Q551; (2): variant R551; (3): control. SHP =SH2 containing phosphatase.