Skip to main content
. Author manuscript; available in PMC: 2016 Aug 1.
Published in final edited form as: Mol Cancer Res. 2015 May 26;13(8):1163–1173. doi: 10.1158/1541-7786.MCR-15-0135

Figure 2. Inhibitors of the Heat Shock Factor 1-dependent Heat Shock Response.

Figure 2

Figure 2

Inhibitors of the Heat Shock Factor 1 (HSF1)-dependent heat shock response are shown above. The mechanism for KRIBB11, Cantharidin, Quercetin/QC12 [a Quercetin prodrug], Triptolide, Rohinitib, and 2,4-Bis(4-hydroxybenzyl)phenol (referred to as (1) above) has been published, while the mechanism for KNK437 has been speculated about. However, the mechanism for NZ28, Emunin, and Stresgenin B remains uncharacterized. (1) KNK437 may repress HSF1 trimerization though no studies have confirmed this hypothesis. (2) To date, no inhibitors have been shown to effect nuclear localization. (3) KRIBB11 and Cantharidin inhibit Positive Transcription Elongation Factor b (P-TEFb) recruitment to HSP promoters. Quercetin/QC12, Cantharidin, and Rohinitib inhibit HSE binding while KNK437 may also inhibit HSE binding. Triptolide inhibits transactivation, and though not shown here, has also been found to decrease HSF1 protein levels in multiple myeloma cell lines.) (1) induces Serine 326 dephosphorylation, leading to a decrease in HSF1 stability and as a result, increased degradation. (4,5) The inhibitor mechanisms presented in (3) accelerate attenuation while no inhibitor to date has been linked to nuclear export. A, acetylation; P, phosphorylation; S, sumoylation.