This Article Full Text Full Text (PDF) Supplemental material Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Kinyamu, H. K. Articles by Archer, T. K. Search for Related Content PubMed PubMed Citation Articles by Kinyamu, H. K. Articles by Archer, T. K.

 Previous Article  |  Next Article 

Molecular and Cellular Biology, July 2007, p. 4891-4904, Vol. 27, No. 13
0270-7306/07/$08.00+0     doi:10.1128/MCB.02162-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

Proteasome Activity Modulates Chromatin Modifications and RNA Polymerase II Phosphorylation To Enhance Glucocorticoid Receptor-Mediated Transcription ^,

H. Karimi Kinyamu and Trevor K. Archer^*

Chromatin and Gene Expression Section, Laboratory of Molecular Carcinogenesis, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina 27709

Received 17 November 2006/ Returned for modification 8 January 2007/ Accepted 6 April 2007

The 26S proteasome modulates steroid hormone receptor-dependent gene transcription at least in part by regulating turnover and recycling of receptor/transcriptional DNA complexes, thereby ensuring continued hormone response. For the glucocorticoid receptor (GR), inhibition of proteasome-mediated proteolysis or RNA interference-mediated depletion of specific proteasome subunits results in an increase in gene expression. To facilitate transcription, proteasome inhibition alters at least two features associated with modification of chromatin architecture and gene transcription. First, proteasome inhibition increases trimethyl histone H3K4 levels with a corresponding accumulation of this modification on GR-regulated promoters in vivo. Secondly, global levels of phosphorylated RNA polymerase II (Pol II) increase, together with hormone-dependent association of the phosphorylated Pol II, with the promoter and the body of the activated gene. We propose that apart from modulating receptor turnover, the proteasome directly influences both the transcription machinery and chromatin structure, factors integral to nuclear receptor-regulated gene transcription.

---

* Corresponding author. Mailing address: Chromatin and Gene Expression Section, Laboratory of Molecular Carcinogenesis, National Institute of Environmental Health Sciences, 111 Alexander Drive, P.O. Box 12233 (MD C4-01), Research Triangle Park, NC 27709. Phone: (919) 316-4565. Fax: (919) 316-4566. E-mail: archer1{at}niehs.nih.gov

Published ahead of print on 16 April 2007.

Supplemental material for this article may be found at http://mcb.asm.org/.

---

Molecular and Cellular Biology, July 2007, p. 4891-4904, Vol. 27, No. 13
0270-7306/07/$08.00+0     doi:10.1128/MCB.02162-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

This article has been cited by other articles:

• Alvarez-Castelao, B., Martin-Guerrero, I., Garcia-Orad, A., Castano, J. G. (2009). Cytomegalovirus Promoter Up-regulation Is the Major Cause of Increased Protein Levels of Unstable Reporter Proteins after Treatment of Living Cells with Proteasome Inhibitors. J. Biol. Chem. 284: 28253-28262 [Abstract] [Full Text]  
• Lin, C.-P., Ban, Y., Lyu, Y. L., Desai, S. D., Liu, L. F. (2008). A Ubiquitin-Proteasome Pathway for the Repair of Topoisomerase I-DNA Covalent Complexes. J. Biol. Chem. 283: 21074-21083 [Abstract] [Full Text]