title: Heat shock transcription factor HSF1 regulates the expression of the Huntingtin-interacting protein HYPK.
abstract: BACKGROUND
  The Huntingtin-interacting protein HYPK possesses chaperone-like activity. We hypothesized that the expression of HYPK could be regulated by heat shock factor HSF1, a transcriptional regulator of chaperone genes.
  
  
  METHODS
  HYPK expression in HeLa cells was assessed by RT-PCR and Western blot analysis. In vivo binding of HSF1 to the HYPK promoter was analyzed by chromatin immunoprecipitation assays. The requirement for HYPK in heat-shocked cells was examined using HYPK-knockdown cells.
  
  
  RESULTS
  Levels of HYPK mRNA were slightly increased by heat treatment; however, the levels decreased in HSF1-silenced cells. The HYPK promoter was bound by HSF1 in a heat-inducible manner; however, its core promoter activity was notably suppressed upon heat shock. When cells were exposed to heat shock, silencing HYPK caused a decrease in cell viability.
  
  
  CONCLUSIONS
  HYPK is a novel target gene of HSF1. HSF1 maintains HYPK expression in heat-shocked cells.
  
  
  CONCLUSIONS
  The maintenance of HYPK expression by HSF1 is necessary for the survival of cells under thermal stress conditions.
authors.affiliation: Division of Health Sciences, Kanazawa University Graduate School of Medical Science, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 920-0942, Japan. Electronic address: hsakurai@staff.kanazawa-u.ac.jp.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sakurai
authors.affiliation: Division of Health Sciences, Kanazawa University Graduate School of Medical Science, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 920-0942, Japan.
authors.forename: Maki
authors.initials: M
authors.lastname: Sawai
authors.affiliation: Division of Health Sciences, Kanazawa University Graduate School of Medical Science, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 920-0942, Japan.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Ishikawa
authors.affiliation: Division of Health Sciences, Kanazawa University Graduate School of Medical Science, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 920-0942, Japan.
authors.forename: Azumi
authors.initials: A
authors.lastname: Ota
authors.affiliation: Division of Health Sciences, Kanazawa University Graduate School of Medical Science, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 920-0942, Japan.
authors.forename: Ei
authors.initials: E
authors.lastname: Kawahara
mesh_terms: D002352:Carrier Proteins / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000502:physiology*; D005786:Gene Expression Regulation; D006367:HeLa Cells; D000076249:Heat Shock Transcription Factors; D006358:Hot Temperature; D006801:Humans; D011401:Promoter Regions, Genetic; D013312:Stress, Physiological; D014157:Transcription Factors / Q000502:physiology*
chemical_list: D002352:Carrier Proteins; D004268:DNA-Binding Proteins; C000619706:HSF1 protein, human; C526912:HYPK protein, human; D000076249:Heat Shock Transcription Factors; D014157:Transcription Factors
keywords: Chaperone; Gene expression; HSF1; HYPK; Stress response