Figure 2. The ΔNLS mutant of ErbB1 is not activated in the presence of nucleolin or in the presence of its ligand, EGF.

HEK-293T cells were co-transfected with pEGFP-nucleolin-Myc and either the wild type ErbB1 or ΔNLS ErbB1 deletion mutant expression vectors. Following 20 minutes serum deprivation, cells were treated with or without EGF (100 ng/ml) for 10 minutes. (A) Cell lysates were immunoblotted with monoclonal antibody anti PY20. As control cell lysates were immunoblotted with polyclonal antibody to ErbB1, or monoclonal antibody anti Myc as indicated. (B) Cell lysates were incubated with BS3 cross linker and immunobloted with polyclonal antibody anti ErbB1.