title: The intron in centromeric noncoding RNA facilitates RNAi-mediated formation of heterochromatin.
abstract: In fission yeast, the formation of centromeric heterochromatin is induced through the RNA interference (RNAi)-mediated pathway. Some pre-mRNA splicing mutants (prp) exhibit defective formation of centromeric heterochromatin, suggesting that splicing factors play roles in the formation of heterochromatin, or alternatively that the defect is caused by impaired splicing of pre-mRNAs encoding RNAi factors. Herein, we demonstrate that the splicing factor spPrp16p is enriched at the centromere, and associates with Cid12p (a factor in the RNAi pathway) and the intron-containing dg ncRNA. Interestingly, removal of the dg intron, mutations of its splice sites, or replacement of the dg intron with an euchromatic intron significantly decreased H3K9 dimethylation. We also revealed that splicing of dg ncRNA is repressed in cells and its repression depends on the distance from the transcription start site to the intron. Inefficient splicing was also observed in other intron-containing centromeric ncRNAs, dh and antisense dg, and splicing of antisense dg ncRNA was repressed in the presence of the RNAi factors. Our results suggest that the introns retained in centromeric ncRNAs work as facilitators, co-operating with splicing factors assembled on the intron and serving as a platform for the recruitment of RNAi factors, in the formation of centromeric heterochromatin.
authors.affiliation: Department of Biological Sciences, Graduate School of Science and Technology, Kumamoto University, Kurokami, Chuo-ku, Kumamoto, Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Mutazono
authors.affiliation: Department of Biological Sciences, Graduate School of Science and Technology, Kumamoto University, Kurokami, Chuo-ku, Kumamoto, Japan.
authors.forename: Misato
authors.initials: M
authors.lastname: Morita
authors.affiliation: Department of Biological Sciences, Graduate School of Science and Technology, Kumamoto University, Kurokami, Chuo-ku, Kumamoto, Japan.
authors.forename: Chihiro
authors.initials: C
authors.lastname: Tsukahara
authors.affiliation: Department of Biological Sciences, Graduate School of Science and Technology, Kumamoto University, Kurokami, Chuo-ku, Kumamoto, Japan.
authors.forename: Madoka
authors.initials: M
authors.lastname: Chinen
authors.affiliation: Department of Biological Sciences, Graduate School of Science and Technology, Kumamoto University, Kurokami, Chuo-ku, Kumamoto, Japan.
authors.forename: Shiori
authors.initials: S
authors.lastname: Nishioka
authors.affiliation: Department of Biological Sciences, Graduate School of Science and Technology, Kumamoto University, Kurokami, Chuo-ku, Kumamoto, Japan.
authors.forename: Tatsuhiro
authors.initials: T
authors.lastname: Yumikake
authors.affiliation: Laboratory of Chromosome Function and Regulation, Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Dohke
authors.affiliation: Department of Biological Sciences, Graduate School of Science and Technology, Kumamoto University, Kurokami, Chuo-ku, Kumamoto, Japan.
authors.forename: Misuzu
authors.initials: M
authors.lastname: Sakamoto
authors.affiliation: Department of Biological Sciences, Graduate School of Science and Technology, Kumamoto University, Kurokami, Chuo-ku, Kumamoto, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Ideue
authors.affiliation: Graduate School of Natural Sciences, Nagoya City University, Nagoya, Japan.|Division of Chromatin Regulation, National Institute for Basic Biology, Okazaki, Japan.
authors.forename: Jun-Ichi
authors.initials: JI
authors.lastname: Nakayama
authors.affiliation: Laboratory of Chromosome Function and Regulation, Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan.
authors.forename: Kojiro
authors.initials: K
authors.lastname: Ishii
authors.affiliation: Department of Biological Sciences, Graduate School of Science and Technology, Kumamoto University, Kurokami, Chuo-ku, Kumamoto, Japan.
authors.forename: Tokio
authors.identifier: 0000-0003-4407-5541
authors.initials: T
authors.lastname: Tani
mesh_terms: D002503:Centromere / Q000235:genetics*; D006570:Heterochromatin / Q000235:genetics*; D007438:Introns / Q000235:genetics; D008745:Methylation; D011062:Polynucleotide Adenylyltransferase / Q000235:genetics*; D034622:RNA Interference; D000072260:RNA Splicing Factors / Q000235:genetics; D022661:RNA, Untranslated / Q000235:genetics*; D012568:Schizosaccharomyces / Q000235:genetics
chemical_list: D006570:Heterochromatin; D000072260:RNA Splicing Factors; D022661:RNA, Untranslated; C459739:Cid13 protein, S pombe; D011062:Polynucleotide Adenylyltransferase