Modulation of yeast genome expression in response to defective RNA polymerase III-dependent transcription.
We used genome-wide expression analysis in Saccharomyces cerevisiae to explore whether and how the expression of protein-coding, RNA polymerase (Pol) II-transcribed genes is influenced by a decrease in RNA Pol III-dependent transcription. The Pol II transcriptome was characterized in four thermosensitive, slow-growth mutants affected in different components of the RNA Pol III transcription machinery. Unexpectedly, we found only a modest correlation between altered expression of Pol II-transcribed genes and their proximity to class III genes, a result also confirmed by the analysis of single tRNA gene deletants. Instead, the transcriptome of all of the four mutants was characterized by increased expression of genes known to be under the control of the Gcn4p transcriptional activator. Indeed, GCN4 was found to be translationally induced in the mutants, and deleting the GCN4 gene eliminated the response. The Gcn4p-dependent expression changes did not require the Gcn2 protein kinase and could be specifically counteracted by an increased gene dosage of initiator tRNA(Met). Initiator tRNA(Met) depletion thus triggers a GCN4-dependent reprogramming of genome expression in response to decreased Pol III transcription. Such an effect might represent a key element in the coordinated transcriptional response of yeast cells to environmental changes.
Conesa
Christine
C
Service de Biochimie et Génétique Moléculaire, Bâtiment 144, CEA/Saclay, 91191 Gif-sur-Yvette Cedex, France. conesa@matthieu.saclay.cea.fr
Ruotolo
Roberta
R
Soularue
Pascal
P
Simms
Tiffany A
TA
Donze
David
D
Sentenac
André
A
Dieci
Giorgio
G
D050976:Basic-Leucine Zipper Transcription Factors; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D017353:Gene Deletion; D018628:Gene Dosage; D005800:Genes, Fungal; D017930:Genes, Reporter; D016681:Genome, Fungal; D006358:Hot Temperature; D007763:Lac Operon; D008715:Methionine / Q000378:metabolism; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D014176:Protein Biosynthesis; D012313:RNA / Q000737:chemistry; D012319:RNA Polymerase II / Q000378:metabolism; D012320:RNA Polymerase III / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D012343:RNA, Transfer / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic; D015533:Transcriptional Activation
D050976:Basic-Leucine Zipper Transcription Factors; D004268:DNA-Binding Proteins; C501391:GCN4 protein, S cerevisiae; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D012313:RNA; D004247:DNA; D012343:RNA, Transfer; D008715:Methionine; D012319:RNA Polymerase II; D012320:RNA Polymerase III