title: Gene expression is circular: factors for mRNA degradation also foster mRNA synthesis.
abstract: Maintaining proper mRNA levels is a key aspect in the regulation of gene expression. The balance between mRNA synthesis and decay determines these levels. We demonstrate that most yeast mRNAs are degraded by the cytoplasmic 5'-to-3' pathway (the "decaysome"), as proposed previously. Unexpectedly, the level of these mRNAs is highly robust to perturbations in this major pathway because defects in various decaysome components lead to transcription downregulation. 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 ∼30 bp upstream of transcription start-sites-and directly stimulate transcription initiation and elongation. The nuclear role of the decaysome in transcription is linked to its cytoplasmic role in mRNA decay; linkage, in turn, seems to depend on proper shuttling of its components. The gene expression process is therefore circular, whereby the hitherto first and last stages are interconnected.
authors.affiliation: Department of Molecular Microbiology, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel.
authors.forename: Gal
authors.initials: G
authors.lastname: Haimovich
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Medina
authors.forename: Sebastien Z
authors.initials: SZ
authors.lastname: Causse
authors.forename: Manuel
authors.initials: M
authors.lastname: Garber
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Millán-Zambrano
authors.forename: Oren
authors.initials: O
authors.lastname: Barkai
authors.forename: Sebastián
authors.initials: S
authors.lastname: Chávez
authors.forename: José E
authors.initials: JE
authors.lastname: Pérez-Ortín
authors.forename: Xavier
authors.initials: X
authors.lastname: Darzacq
authors.forename: Mordechai
authors.initials: M
authors.lastname: Choder
mesh_terms: D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D005095:Exoribonucleases / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal / Q000235:genetics; D012319:RNA Polymerase II / Q000378:metabolism; D020871:RNA Stability; D012331:RNA, Fungal / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D012331:RNA, Fungal; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins; D012319:RNA Polymerase II; D005095:Exoribonucleases; C068398:XRN1 protein, S cerevisiae