Distribution of elongating RNA polymerase II along the 5'/3' regions in xrn1 mutants

ABSTRACT: Determination of the 3' or 5' intragenic nascent transcriptional rate. Maintaining the proper mRNA levels is a key aspect in the regulation of gene expression. The balance between mRNA synthesis and decay determines these levels. Using a whole-genome analysis, we demonstrate that most yeast mRNAs are degraded by the 5'-to-3' pathway (the "decaysome"), as proposed previously. Unexpectedly, the level of these mRNAs is highly robust to perturbations in this major pathway, as defects in various decaysome components lead to transcription down-regulation. Moreover, these components shuttle between the cytoplasm and the nucleus, in a manner dependent on proper mRNA degradation. In the nucleus, they associate with chromatin - preferentially ~30bp upstream of transcription start-sites - and directly stimulate transcription initiation and elongation. Hence, the decaysome has a dual role in maintaining mRNA levels. Significantly, proper import of some decaysome components seems to play a key role in coupling the two functions. The gene expression process is therefore circular, whereby the hitherto first and last stages are interconnected. This study focuses on the transcriptional activity of RNA pol II in the 3' or 5' region of 377 S. cerevisiae ORFs. S. cerevisiae cells grown in YPD to exponential phase were subjected to Genomic Run-On. Data were normalized using gDNA hybridized on the same array. Home-made macroarrays containing 300 bp from both the 5' or 3' ends of each ORF were used.

ORGANISM(S): Saccharomyces cerevisiae

SUBMITTER: Jose Perez-Ortin 

PROVIDER: E-GEOD-43602 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress