EXPRESSION AND PURIFICATION OF HUMAN HEAT-SHOCK TRANSCRIPTION FACTOR-1

Heat-shock factor 1 (HSF1) is a 57-kDa cytoplasmic protein which binds to the promoters of heat-shock genes and activates transcription duri ng heat shock. We describe here the expression and purification of the 529 amino acids form of human HSF1. We designed a new and complete pu rification protocol involving ammonium sulfate precipitation, heparin- Sepharose affinity, and ion-exchange chromatography, which allows the purification of large amounts of pure and active recombinant protein. HSF1 isolated by this method is pure as that assessed by SDS-PAGE and reverse-phase HPLC. The purified protein is recognized by specific ant i-HSF1 antibodies, binds to heat-shock elements, and activates the pro moter of the heat-shock protein 70A gene in vitro. (C) 1997 Academic P ress.