MCB IAI Online 2003
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Supplemental material
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Gardner, R. G.
Right arrow Articles by Gottschling, D. E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Gardner, R. G.
Right arrow Articles by Gottschling, D. E.
Molecular and Cellular Biology, July 2005, p. 6123-6139, Vol. 25, No. 14
0270-7306/05/$08.00+0     doi:10.1128/MCB.25.14.6123-6139.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.

Ubp10/Dot4p Regulates the Persistence of Ubiquitinated Histone H2B: Distinct Roles in Telomeric Silencing and General Chromatin{dagger}

Richard G. Gardner, Zara W. Nelson, and Daniel E. Gottschling*

Fred Hutchinson Cancer Research Center, Seattle, Washington 98109

Received 16 February 2005/ Returned for modification 23 March 2005/ Accepted 8 April 2005

We previously discovered that the ubiquitin protease Ubp10/Dot4p is important for telomeric silencing through its interaction with Sir4p. However, the mechanism of Ubp10p action was unknown. We now provide evidence that Ubp10p removes ubiquitin from histone H2B; cells with UBP10 deleted have increased steady-state levels of H2B ubiquitination. As a consequence, ubp10{Delta} cells also have increased steady-state levels of histone H3 Lys4 and Lys79 methylation. Consistent with its role in silencing, Ubp10p is preferentially localized to silent chromatin where its ubiquitin protease activity maintains low levels of H3 Lys4 and Lys79 methylation to allow optimal Sir protein binding to telomeres and global telomeric silencing. The ubiquitin protease Ubp8p has also been shown to remove ubiquitin from H2B, and ubp8{Delta} cells have increased steady-state levels of H2B ubiquitination similar to those in ubp10{Delta} cells. Unlike ubp10{Delta} cells, however, ubp8{Delta} cells do not have increased steady-state levels of H3 Lys4 and Lys79 methylation, nor is telomeric silencing affected. Despite their separate functions in silencing and SAGA-mediated transcription, respectively, deletion of both UBP10 and UBP8 results in a synergistic increase in the steady-state levels of H2B ubiquitination and in the number of genes with altered expression, indicating that Ubp10p and Ubp8p likely overlap in some of their target chromatin regions. We propose that Ubp10p and Ubp8p are the only ubiquitin proteases that normally remove monoubiquitin from histone H2B and, while there are regions of the genome to which each is specifically targeted, both combine to regulate the global balance of H2B ubiquitination.


* Corresponding author. Mailing address: Fred Hutchinson Cancer Research Center, Mail stop A3-025, P.O. Box 19024, Seattle, WA 98109-1024. Phone: (206) 667-4494. Fax: (206) 667-5894. E-mail: dgottsch{at}fhcrc.org.

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


Molecular and Cellular Biology, July 2005, p. 6123-6139, Vol. 25, No. 14
0022-538X/05/$08.00+0     doi:10.1128/MCB.25.14.6123-6139.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.




This article has been cited by other articles:




Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. J. Virol. Eukaryot. Cell
Microbiol. Mol. Biol. Rev. Clin. Vaccine Immunol. All ASM Journals

Copyright © 2005 by the American Society for Microbiology. All rights reserved.