Abstract
In contrast to most genomic DNA in mitotic cells, the promoter regions of some genes, such as the stress-inducible hsp70i gene that codes for a heat shock protein, remain uncompacted, a phenomenon called bookmarking. Here we show that hsp70i bookmarking is mediated by a transcription factor called HSF2, which binds this promoter in mitotic cells, recruits protein phosphatase 2A, and interacts with the CAP-G subunit of the condensin enzyme to promote efficient dephosphorylation and inactivation of condensin complexes in the vicinity, thereby preventing compaction at this site. Blocking HSF2-mediated bookmarking by HSF2 RNA interference decreases hsp70i induction and survival of stressed cells in the G1 phase, which demonstrates the biological importance of gene bookmarking.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Adenosine Triphosphatases / metabolism
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Cell Line, Tumor
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Chromatin Immunoprecipitation
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DNA-Binding Proteins / metabolism
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Gene Expression Regulation*
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HSP70 Heat-Shock Proteins / genetics*
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HeLa Cells
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Heat-Shock Proteins / genetics
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Heat-Shock Proteins / metabolism*
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Hot Temperature
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Humans
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Immunoprecipitation
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Interphase
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Mitosis*
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Multiprotein Complexes
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Phosphoprotein Phosphatases / metabolism
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Phosphorylation
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Promoter Regions, Genetic*
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Protein Binding
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Protein Phosphatase 2
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Protein Subunits / metabolism
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RNA Interference
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RNA, Small Interfering / pharmacology
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Transcription Factors / genetics
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Transcription Factors / metabolism*
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Two-Hybrid System Techniques
Substances
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DNA-Binding Proteins
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HSP70 Heat-Shock Proteins
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Heat-Shock Proteins
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Multiprotein Complexes
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Protein Subunits
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RNA, Small Interfering
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Transcription Factors
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condensin complexes
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HSF2 protein, human
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Phosphoprotein Phosphatases
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Protein Phosphatase 2
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Adenosine Triphosphatases