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 arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Rosas-Hernández, L. L.
Right arrow Articles by Castaño, I.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Rosas-Hernández, L. L.
Right arrow Articles by Castaño, I.

 Previous Article  |  Next Article 

Eukaryotic Cell, December 2008, p. 2168-2178, Vol. 7, No. 12
1535-9778/08/$08.00+0     doi:10.1128/EC.00228-08
Copyright © 2008, American Society for Microbiology. All Rights Reserved.

yKu70/yKu80 and Rif1 Regulate Silencing Differentially at Telomeres in Candida glabrata{triangledown} ,{ddagger}

Lluvia L. Rosas-Hernández,1,{dagger} Alejandro Juárez-Reyes,1,{dagger} Omar E. Arroyo-Helguera,1 Alejandro De Las Peñas,1 Shih-Jung Pan,2 Brendan P. Cormack,2 and Irene Castaño1*

Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa San José #2055, Lomas 4a Sección, San Luis Potosí SLP, México,1 Johns Hopkins University, 725 North Wolfe St., Baltimore, Maryland 212052

Received 12 July 2008/ Accepted 25 September 2008

Candida glabrata, a common opportunistic fungal pathogen, adheres efficiently to mammalian epithelial cells in culture. This interaction in vitro depends mainly on the adhesin Epa1, one of a large family of cell wall proteins. Most of the EPA genes are located in subtelomeric regions, where they are transcriptionally repressed by silencing. In order to better characterize the transcriptional regulation of the EPA family, we have assessed the importance of C. glabrata orthologues of known regulators of subtelomeric silencing in Saccharomyces cerevisiae. To this end, we used a series of strains containing insertions of the reporter URA3 gene within different intergenic regions throughout four telomeres of C. glabrata. Using these reporter strains, we have assessed the roles of SIR2, SIR3, SIR4, HDF1 (yKu70), HDF2 (yKu80), and RIF1 in mediating silencing at four C. glabrata telomeres. We found that, whereas the SIR proteins are absolutely required for silencing of the reporter genes and the native subtelomeric EPA genes, the Rif1 and the Ku proteins regulate silencing at only a subset of the analyzed telomeres. We also mapped a cis element adjacent to the EPA3 locus that can silence a reporter gene when placed at a distance of 31 kb from the telomere. Our data show that silencing of the C. glabrata telomeres varies from telomere to telomere. In addition, recruitment of silencing proteins to the subtelomeres is likely, for certain telomeres, to depend both on the telomeric repeats and on particular discrete silencing elements.

* Corresponding author. Mailing address: División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa San José #2055, San Luis Potosí, San Luis Potosí 78216, México. Phone: (52) 444-834-2000, x2039. Fax: (52) 444-834-2010. E-mail: icastano{at}ipicyt.edu.mx

{triangledown} Published ahead of print on 3 October 2008.

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

{dagger} L.L.R.-H. and A.J.-R. contributed equally to this study.

Eukaryotic Cell, December 2008, p. 2168-2178, Vol. 7, No. 12
1535-9778/08/$08.00+0     doi:10.1128/EC.00228-08
Copyright © 2008, American Society for Microbiology. All Rights Reserved.





Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»