Fig. 4. The oligomerization domain HR-A/B is essential for the physical interaction between HSF1 and HSF2. (A) Schematic presentation of HSF2 deletion mutants. The DNA-binding domain (DBD), N-terminal oligomerization domain (HR-A/B) and C-terminal leucine zipper (HR-C) are indicated. (B) Anti-Myc antibodies were used to immunoprecipitate HSF1, and antibodies against HSF1 and HSF2 were used for western blotting. An empty Myc vector was used in the mock transfections. The expression levels were analyzed by western blotting (WB), as indicated. Arrows and asterisks indicate the inducibly phosphorylated HSF1 and the endogenous HSF2, respectively. Molecular weights (kDa) are shown.