Figure 3.
A motif within the kinase domain of ErbB-2 confers recognition by Hsp90. (A) SKBR3 cells were treated with GA (5 μM; 5 min). Cells were then lysed and the interactions of the different ErbBs with Hsp90 determined by analysing co-immunoprecipitation in comparison with whole-cell lysates (WCLs). (B) Model of the kinase domain of ErbB-2 depicting the αC helix and β4 strand (both in silver), αC–β4 loop (red), activation loop (yellow) and the ATP-binding lysine (green). (C) Sequence alignment of the region corresponding to the putative Hsp90-binding loop of ErbB-2. A box marks the amino acids swapped in the 1L2 and 2L1 chimaeras. (D) HEK-293T cells were transfected with plasmids encoding HA-tagged ubiquitin and either ErbB-1, 1L2, ErbB-2 or 2L1. After 48 h, cells were subjected to the indicated analysis.