Mechanism of hsp70i Gene Bookmarking
2005; American Association for the Advancement of Science; Volume: 307; Issue: 5708 Linguagem: Inglês
10.1126/science.1106478
ISSN1095-9203
AutoresHongyan Xing, Donald C. Wilkerson, Christopher N. Mayhew, Eric J. Lubert, Hollie S. Skaggs, Michael L. Goodson, Yiling Hong, Ok-Kyong Park-Sarge, Kevin D. Sarge,
Tópico(s)RNA Research and Splicing
ResumoIn 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.
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