title: Cytoplasmic 5'-3' exonuclease Xrn1p is also a genome-wide transcription factor in yeast.
abstract: The 5' to 3' exoribonuclease Xrn1 is a large protein involved in cytoplasmatic mRNA degradation as a critical component of the major decaysome. Its deletion in the yeast Saccharomyces cerevisiae is not lethal, but it has multiple physiological effects. In a previous study, our group showed that deletion of all tested components of the yeast major decaysome, including XRN1, results in a decrease in the synthetic rate and an increase in half-life of most mRNAs in a compensatory manner. Furthermore, the same study showed that the all tested decaysome components are also nuclear proteins that bind to the 5' region of a number of genes. In the present work, we show that disruption of Xrn1 activity preferentially affects both the synthesis and decay of a distinct subpopulation of mRNAs. The most affected mRNAs are the transcripts of the highly transcribed genes, mainly those encoding ribosome biogenesis and translation factors. Previously, we proposed that synthegradases play a key role in regulating both mRNA synthesis and degradation. Evidently, Xrn1 functions as a synthegradase, whose selectivity might help coordinating the expression of the protein synthetic machinery. We propose to name the most affected genes "Xrn1 synthegradon."
authors.affiliation: Departamento de Bioquímica y Biología Molecular and ERI Biotecmed, Universitat de València Burjassot, Spain.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Medina
authors.affiliation: Departamento de Bioquímica y Biología Molecular and ERI Biotecmed, Universitat de València Burjassot, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Jordán-Pla
authors.affiliation: Departamento de Genética and Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla Seville, Spain.
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Millán-Zambrano
authors.affiliation: Departamento de Genética and Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla Seville, Spain.
authors.forename: Sebastián
authors.initials: S
authors.lastname: Chávez
authors.affiliation: Faculty of Medicine, Department of Molecular Microbiology, Technion-Israel Institute of Technology Haifa, Israel.
authors.forename: Mordechai
authors.initials: M
authors.lastname: Choder
authors.affiliation: Departamento de Bioquímica y Biología Molecular and ERI Biotecmed, Universitat de València Burjassot, Spain.
authors.forename: José E
authors.initials: JE
authors.lastname: Pérez-Ortín
keywords: mRNA decay; mRNA stability; mRNA synthesis; nascent transcription; transcription rate