title: HSF1 transcriptional activity is modulated by IER5 and PP2A/B55.
abstract: Heat shock factor 1 (HSF1) is the master transcriptional regulator of chaperone genes. HSF1 regulates the expression of the immediate-early response gene IER5, which encodes a protein that has roles in the stress response and cell proliferation. Here, we have shown that IER5 interacts with protein phosphatase 2A (PP2A) and its B55 regulatory subunits. Expression of IER5 and B55 in cells leads to HSF1 dephosphorylation and activation of HSF1 target genes. The B55 subunits directly bind to HSF1. These results suggest that IER5 functions as a positive feedback regulator of HSF1 and that this process involves PP2A/B55 and HSF1 dephosphorylation.
authors: Division of Health Sciences, Kanazawa University Graduate School of Medical Science, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 920-0942, Japan.
authors: Yukio
authors: Y
authors: Ishikawa
authors: Division of Health Sciences, Kanazawa University Graduate School of Medical Science, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 920-0942, Japan.
authors: Shotaro
authors: S
authors: Kawabata
authors: 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: Hiroshi
authors: H
authors: Sakurai
mesh_terms: D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology*; D006367:HeLa Cells; D000076249:Heat Shock Transcription Factors; D006801:Humans; D017874:Immediate-Early Proteins / Q000235:genetics / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation / Q000502:physiology; D054648:Protein Phosphatase 2 / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D004268:DNA-Binding Proteins; C000619706:HSF1 protein, human; D000076249:Heat Shock Transcription Factors; C118926:IER5 protein, human; D017874:Immediate-Early Proteins; D009687:Nuclear Proteins; C512974:PPP2R2A protein, human; D014157:Transcription Factors; D054648:Protein Phosphatase 2
keywords: Chaperone; Heat shock factor 1; IER5; Immediate-early gene; Phosphorylation; Protein phosphatase 2A