Fig 5.

Interactions between TBP and HSF1 demonstrated by coimmunoprecipitation. Chimeric proteins GAL4-AD2, GAL4-AD1+2, or GAL4-AD2 (MA-1) were coimmunoprecipitated with T7-tagged TBP coexpressed in HeLa cells. Plus sign (+) represents the presence of each plasmid in the transfection mixture. The AD2 (MA-1) construct contains a mutated AD2 that is severely impaired in transcriptional activity when assayed in yeast cells (Yuan et al 1997). Protein complexes were first immunoprecipitated using anti-GAL4 DBD antibody covalently cross-linked to protein A-Sepharose beads. The presence of T7-tagged TBP in the complexes was then detected by probing the Western blot with anti-T7 tag antibody