FIG. 3.

Substitution of amino-terminal sequence of cHSF1 with that of hHSF1 does not alter the DNA binding activity, heat-induced phosphorylation, and nuclear translocation of cHSF1. (A) Wild-type DT40 cells, HSF3^−/− cells, and HSF3^−/− cells having cHSF1, hHSF1, and chimeric h20/c or c126/h were heat shocked at 45°C for 60 min. Northern blot analysis was performed. (B) The cells shown in panel A were heat shocked at 45°C for 60 min, and whole-cell extracts were prepared. The gel shift assay was performed with the ³²P-labeled heat shock element probe. (C) Western blot analysis of the whole-cell extracts isolated in panel B was performed with HSF1 antibody. (D) Cells were treated as described for panel B. Cytoplasmic (c) and nuclear (n) extracts were prepared, and Western blot analysis of the extracts was performed with HSF1 antibody.