Braglia P, et al. (2007) Requirement of Nhp6 Proteins for Transcription of a Subset of tRNA Genes and Heterochromatin Barrier Function in Saccharomyces cerevisiae. Mol Cell Biol 27(5):1545-57
Abstract: A key event in tRNA gene transcription by RNA polymerase III is the TFIIIC-dependent assembly of TFIIIB upstream of the transcription start site. Different tDNA upstream sequences bind TFIIIB with different affinities, thereby modulating tDNA transcription. We found that, in the absence of Nhp6 proteins, the influence of the 5'-flanking region on tRNA gene transcription is dramatically enhanced in Saccharomyces cerevisiae. Expression of a tDNA bearing a sub-optimal TFIIIB binding site, but not of a tDNA preceded by a strong TFIIIB binding region, was strongly dependent on Nhp6 in vivo. Upstream sequence-dependent stimulation of tRNA gene transcription by Nhp6 could be reproduced in vitro, and Nhp6 proteins were found associated to tRNA genes in yeast cells. We also show that both transcription and silencing barrier activity of a tDNA(Thr) at the HMR locus are compromised in the absence of Nhp6. Our data suggest that Nhp6 proteins are important components of Pol III chromatin templates, that contribute both to the robustness of tRNA gene expression and to positional effects of Pol III transcription complexes.
|Status: Published||Type: Journal Article||PubMed ID: 17178828|
Topics addressed in this paper
Number of different genes curated to this paper: 9
- To go to the Locus page for a gene, click on the gene name.
|DNA/RNA Sequence Features|
|Protein-Nucleic Acid Interactions|
|Techniques and Reagents|