Fig 5.

 Intracellular localization of heat shock transcription factor 1 (HSF1) in HeLa cells. (A and B) Nontreated control cells; (C and D) cells heated at 42°C for 2 hours; (E, F, G, and H) cells treated with paeoniflorin (PF) for 4, 8, 16, and 24 hours, respectively; (I, J, K, and L) cells treated with glycyrrhizin (GL) for 4, 8, 16, and 24 hours, respectively. HSF1 is localized both in the cytoplasm and the nucleus in nontreated control cells (B). Treatment of cells with heat shock (D) or with paeoniflorin for 4 and 8 hours (E and F) induced relocalization of HSF1 into the nucleus to form typical HSF1 granules. Continuous treatment of cells with paeoniflorin for 16 and 24 hours resulted in the disappearance of HSF1 granules, indicating attenuation of HSF1 activity. Treatment of cells with glycyrrhizin resulted in the gradual relocalization of HSF1 into the nucleus (I–L). The phase-contrast micrographs are shown in A and C; the HSF1-specific fluorescence micrographs of each corresponding field are shown in B and D