Novel gene switches for targeted and timed expression of proteins of interest.

This article reports on the construction and analysis in vitro and in vivo of novel gene switches that can be used to achieve spatial as well as temporal control over the expression of a transgene of interest. The switches are expected to be functional in virtually any tissue and cell type. They consist of (a) a foreign or modified transactivator expressed under the dual control of a promoter or promoter cassette that is responsive to heat and the transactivator and (b) a promoter responsive to the transactivator for controlling the transgene of interest.

Evidence for a mechanism of repression of heat shock factor 1 transcriptional activity by a multichaperone complex.

In the absence of stress, human heat shock factor 1 (hHSF1) is in its unactivated form. hHSF1 polypeptide is in a dynamic heterocomplex with Hsp90 and is incapable of specifically binding DNA. When cells are stressed, heterocomplex assembly is disrupted.

Heat shock protein induction in murine liver after acute treatment with cocaine.

The effect of cocaine on heat shock protein (hsp) induction in murine liver was examined using Western blotting and immunohistochemistry. A single dose of cocaine (50 mg/kg, intraperitoneal [i.p.

Purified human factor activates heat shock promoter in a HeLa cell-free transcription system.

Heat shock protein (hsp) genes are typically silent and are activated by various stresses including heat. As a first step toward understanding this activation event, a human factor, referred to here as human heat shock transcription factor (human HTF), has been purified approximately 14,000-fold from extracts of heat-treated HeLa cells by means of sequence-specific DNA affinity chromatography. The most highly purified fraction of human HTF binds specifically to the known regulatory sequence element (HSE) of hsp genes as shown by footprinting experiments.