Published online 30 September 2004
Nucleic Acids Research, Vol. 32 No. 17 © Oxford University Press 2004; all rights reserved
The Saccharomyces cerevisiae TRT2 tRNAThr gene upstream of STE6 is a barrier to repression in MAT
cells and exerts a potential tRNA position effect in MATa cells
Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
* To whom correspondence should be addressed. Tel: +1 225 578 7391; Fax: +1 225 578 2597; Email: ddonze{at}lsu.edu
Received May 26, 2004; Revised and Accepted September 10, 2004
A growing body of evidence suggests that genes transcribed by RNA polymerase III exhibit multiple functions within a chromosome. While the predominant function of these genes is the synthesis of RNA molecules, certain RNA polymerase III genes also function as genomic landmarks. Transfer RNA genes are known to exhibit extra-transcriptional activities such as directing Ty element integration, pausing of replication forks, overriding nucleosome positioning sequences, repressing neighboring genes (tRNA position effect), and acting as a barrier to the spread of repressive chromatin. This study was designed to identify other tRNA loci that may act as barriers to chromatin-mediated repression, and focused on TRT2, a tRNAThr adjacent to the STE6 
2 operator. We show that TRT2 acts as a barrier to repression, protecting the upstream CBT1 gene from the influence of the STE6 2 operator in MAT cells. Interestingly, deletion of TRT2 results in an increase in CBT1 mRNA levels in MATa cells, indicating a potential tRNA position effect. The transcription of TRT2 itself is unaffected by the presence of the 2 operator, suggesting a hierarchy that favors assembly of the RNA polymerase III complex versus assembly of adjacent 2 operator-mediated repressed chromatin structures. This proposed hierarchy could explain how tRNA genes function as barriers to the propagation of repressive chromatin.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  L. Valenzuela, N. Dhillon, and R. T. Kamakaka Transcription Independent Insulation at TFIIIC-Dependent Insulators Genetics, September 1, 2009; 183(1): 131 - 148. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Zhou, B. O. Zhou, B. A. Lenzmeier, and J.-Q. Zhou Histone deacetylase Rpd3 antagonizes Sir2-dependent silent chromatin propagation Nucleic Acids Res., June 1, 2009; 37(11): 3699 - 3713. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Biswas, N. Maqani, R. Rai, S. P. Kumaran, K. R. Iyer, E. Sendinc, J. S. Smith, and S. Laloraya Limiting the Extent of the RDN1 Heterochromatin Domain by a Silencing Barrier and Sir2 Protein Levels in Saccharomyces cerevisiae Mol. Cell. Biol., May 15, 2009; 29(10): 2889 - 2898. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. A. Simms, S. L. Dugas, J. C. Gremillion, M. E. Ibos, M. N. Dandurand, T. T. Toliver, D. J. Edwards, and D. Donze TFIIIC Binding Sites Function as both Heterochromatin Barriers and Chromatin Insulators in Saccharomyces cerevisiae Eukaryot. Cell, December 1, 2008; 7(12): 2078 - 2086. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Braglia, S. L. Dugas, D. Donze, and G. Dieci Requirement of Nhp6 Proteins for Transcription of a Subset of tRNA Genes and Heterochromatin Barrier Function in Saccharomyces cerevisiae Mol. Cell. Biol., March 1, 2007; 27(5): 1545 - 1557. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. Guffanti, R. Percudani, O. Harismendy, J. Soutourina, M. Werner, M. G. Iacovella, R. Negri, and G. Dieci Nucleosome Depletion Activates Poised RNA Polymerase III at Unconventional Transcription Sites in Saccharomyces cerevisiae J. Biol. Chem., September 29, 2006; 281(39): 29155 - 29164. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Conesa, R. Ruotolo, P. Soularue, T. A. Simms, D. Donze, A. Sentenac, and G. Dieci Modulation of Yeast Genome Expression in Response to Defective RNA Polymerase III-Dependent Transcription Mol. Cell. Biol., October 1, 2005; 25(19): 8631 - 8642. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. Bachman, M. E. Gelbart, T. Tsukiyama, and J. D. Boeke TFIIIB subunit Bdp1p is required for periodic integration of the Ty1 retrotransposon and targeting of Isw2p to S. cerevisiae tDNAs Genes & Dev., April 15, 2005; 19(8): 955 - 964. [Abstract] [Full Text] [PDF]
|
|