title: RNA interference regulates the cell cycle checkpoint through the RNA export factor, Ptr1, in fission yeast.
abstract: Ago1, an effector protein of RNA interference (RNAi), regulates heterochromatin silencing and cell cycle arrest in fission yeast. However, the mechanism by which Ago1 controls cell cycle checkpoint following hydroxyurea (HU) treatment has not been elucidated. In this study, we show that Ago1 and other RNAi factors control cell cycle checkpoint following HU treatment via a mechanism independent of silencing. While silencing requires dcr1(+), the overexpression of ago1(+) alleviated the cell cycle defect in dcr1Δ. Ago1 interacted with the mRNA export factor, Ptr1. The ptr1-1 mutation impaired cell cycle checkpoint but gene silencing was unaffected. Genetic analysis revealed that the regulation of cell cycle checkpoint by ago1(+) is dependent on ptr1(+). Nuclear accumulation of poly(A)(+) RNAs was detected in mutants of ago1(+) and ptr1(+), suggesting there is a functional link between the cell cycle checkpoint and RNAi-mediated RNA quality control.
authors.affiliation: Division of Cytogenetics, National Institute of Genetics, Mishima, 1111 Yata, Mishima 411-8540, Japan. tiida@nig.ac.jp
authors.forename: Tetsushi
authors.initials: T
authors.lastname: Iida
authors.forename: Naoko
authors.initials: N
authors.lastname: Iida
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Tsutsui
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Yamao
authors.forename: Takehiko
authors.initials: T
authors.lastname: Kobayashi
mesh_terms: D060565:Argonaute Proteins / Q000235:genetics / Q000378:metabolism*; D059447:Cell Cycle Checkpoints / Q000235:genetics*; D002467:Cell Nucleus / Q000378:metabolism; D006570:Heterochromatin / Q000378:metabolism; D006918:Hydroxyurea / Q000494:pharmacology; D009154:Mutation; D034521:Nuclear Matrix-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D029543:Nucleocytoplasmic Transport Proteins / Q000235:genetics / Q000378:metabolism*; D017393:RNA Editing; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012568:Schizosaccharomyces / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: C481643:Ago1 protein, S pombe; D060565:Argonaute Proteins; D006570:Heterochromatin; D034521:Nuclear Matrix-Associated Proteins; D029543:Nucleocytoplasmic Transport Proteins; D012333:RNA, Messenger; D029702:Schizosaccharomyces pombe Proteins; C092953:rae1 protein, S pombe; D006918:Hydroxyurea