Multiple Layers of Regulation of Human Heat Shock Transcription Factor 1

• DOI: 10.1128/mcb.15.8.4319
• Publication Date: 2015-10-09T00:17:05Z
• Authors: Jianru Zuo; Duri Rungger; Richard Voellmy
• Keywords: Heat shock factor; Transcription

Upon heat stress, monomeric human shock transcription factor 1 (hHSF1) is converted to a trimer, acquires DNA-binding ability, transported the nucleus, and becomes transcriptionally competent. It was not known previously whether these regulatory changes are caused by single activation event or they occur independently from one another, providing multilayered control that may prevent inadvertant of hHSF1. Comparison wild-type mutant hHSF1 expressed in Xenopus oocytes HeLa cells suggested retention form depends on hydrophobic repeats (LZ1 LZ3) carboxy-terminal sequence element as well presence titratable cell. Oligomerization appears induce activity uncover an amino-terminally located nuclear localization signal. A mechanism distinct controlling oligomerization regulates transcriptional competence Components this were mapped region, including LZ2 nearby sequences downstream LZ2, clearly separated carboxy-terminally domain(s). We propose existence fold-back structure masks domain unstressed cell but opened up modification and/or binding facilitating unfolding stressed Activation involve at least two regulated structural transitions.