title: Cuf2 Is a Transcriptional Co-Regulator that Interacts with Mei4 for Timely Expression of Middle-Phase Meiotic Genes.
abstract: The Schizosaccharomyces pombe cuf2+ gene encodes a nuclear regulator that is required for timely activation and repression of several middle-phase genes during meiotic differentiation. In this study, we sought to gain insight into the mechanism by which Cuf2 regulates meiotic gene expression. Using a chromatin immunoprecipitation approach, we demonstrate that Cuf2 is specifically associated with promoters of both activated and repressed target genes, in a time-dependent manner. In case of the fzr1+ gene whose transcription is positively affected by Cuf2, promoter occupancy by Cuf2 results in a concomitant increased association of RNA polymerase II along its coding region. In marked contrast, association of RNA polymerase II with chromatin decreases when Cuf2 negatively regulates target gene expression such as wtf13+. Although Cuf2 operates through a transcriptional mechanism, it is unable to perform its function in the absence of the Mei4 transcription factor, which is a member of the conserved forkhead protein family. Using coimmunoprecipitation experiments, results showed that Cuf2 is a binding partner of Mei4. Bimolecular fluorescence complementation experiments brought further evidence that an association between Cuf2 and Mei4 occurs in the nucleus. Analysis of fzr1+ promoter regions revealed that two FLEX-like elements, which are bound by the transcription factor Mei4, are required for chromatin occupancy by Cuf2. Together, results reported here revealed that Cuf2 and Mei4 co-regulate the timely expression of middle-phase genes during meiosis.
authors.affiliation: Département de Biochimie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, QC, J1E 4K8, Canada.
authors.forename: Raphaël
authors.initials: R
authors.lastname: Ioannoni
authors.affiliation: Département de Biochimie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, QC, J1E 4K8, Canada.
authors.forename: Ariane
authors.initials: A
authors.lastname: Brault
authors.affiliation: Département de Biochimie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, QC, J1E 4K8, Canada.
authors.forename: Simon
authors.initials: S
authors.lastname: Labbé
mesh_terms: D018797:Cell Cycle Proteins / Q000502:physiology*; D047369:Chromatin Immunoprecipitation; D015966:Gene Expression Regulation, Fungal / Q000235:genetics / Q000502:physiology; D005800:Genes, Fungal / Q000235:genetics / Q000502:physiology; D008540:Meiosis / Q000235:genetics* / Q000502:physiology; D008856:Microscopy, Fluorescence; D011401:Promoter Regions, Genetic / Q000235:genetics / Q000502:physiology; D012331:RNA, Fungal / Q000235:genetics / Q000502:physiology; D012568:Schizosaccharomyces / Q000235:genetics / Q000502:physiology; D029702:Schizosaccharomyces pombe Proteins / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*
chemical_list: D018797:Cell Cycle Proteins; C574673:Cuf2 protein, S pombe; D012331:RNA, Fungal; D029702:Schizosaccharomyces pombe Proteins; D014157:Transcription Factors; C489539:mei4 protein, S pombe