FIGURE 7.

Effect of HSP70 on the transcription of the tyrosinase gene in nuclear extract. HSP70-overepressing B16 cells (HSP70 +) or mock transfectant control cells (HSP70 −) were incubated for 3 h with or without 100 μm IBMX. Nuclear extracts were prepared and incubated with DNA fragments containing the tyrosinase or grp78 promoter region in the presence (B) or absence (A) of indicated amounts of purified HSP70 (B). Isolated RNAs were electrophoresed on a 15% polyacrylamide gel and autoradiographed.