title: Spatial control of translation repression and polarized growth by conserved NDR kinase Orb6 and RNA-binding protein Sts5.
abstract: RNA-binding proteins contribute to the formation of ribonucleoprotein (RNP) granules by phase transition, but regulatory mechanisms are not fully understood. Conserved fission yeast NDR (Nuclear Dbf2-Related) kinase Orb6 governs cell morphogenesis in part by spatially controlling Cdc42 GTPase. Here we describe a novel, independent function for Orb6 kinase in negatively regulating the recruitment of RNA-binding protein Sts5 into RNPs to promote polarized cell growth. We find that Orb6 kinase inhibits Sts5 recruitment into granules, its association with processing (P) bodies, and degradation of Sts5-bound mRNAs by promoting Sts5 interaction with 14-3-3 protein Rad24. Many Sts5-bound mRNAs encode essential factors for polarized cell growth, and Orb6 kinase spatially and temporally controls the extent of Sts5 granule formation. Disruption of this control system affects cell morphology and alters the pattern of polarized cell growth, revealing a role for Orb6 kinase in the spatial control of translational repression that enables normal cell morphogenesis.
authors.affiliation: Molecular and Cellular Pharmacology, University of Miami School of Medicine, Miami, United States.
authors.forename: Illyce
authors.initials: I
authors.lastname: Nuñez
authors.affiliation: Molecular and Cellular Pharmacology, University of Miami School of Medicine, Miami, United States.
authors.forename: Marbelys
authors.initials: M
authors.lastname: Rodriguez Pino
authors.affiliation: Molecular and Cellular Pharmacology, University of Miami School of Medicine, Miami, United States.
authors.forename: David J
authors.initials: DJ
authors.lastname: Wiley
authors.affiliation: Department of Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, United States.
authors.forename: Maitreyi E
authors.initials: ME
authors.lastname: Das
authors.affiliation: Molecular and Cellular Pharmacology, University of Miami School of Medicine, Miami, United States.
authors.forename: Chuan
authors.initials: C
authors.lastname: Chen
authors.affiliation: National Research Institute of Brewing, Higashi-Hiroshima, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Goshima
authors.affiliation: Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima, Japan.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Kume
authors.affiliation: Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima, Japan.
authors.forename: Dai
authors.initials: D
authors.lastname: Hirata
authors.affiliation: Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima, Japan.|The Francis Crick Institute, Lincoln's Inn Fields Laboratory, London, United Kingdom.
authors.forename: Takashi
authors.initials: T
authors.lastname: Toda
authors.affiliation: Molecular and Cellular Pharmacology, University of Miami School of Medicine, Miami, United States.|Marine Biological Laboratory, Woods Hole, United States.
authors.forename: Fulvia
authors.identifier: 0000-0002-2575-0823
authors.initials: F
authors.lastname: Verde
mesh_terms: D018797:Cell Cycle Proteins / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D008856:Microscopy, Fluorescence; D014176:Protein Biosynthesis; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D012568:Schizosaccharomyces / Q000166:cytology* / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D029702:Schizosaccharomyces pombe Proteins / Q000378:metabolism*
chemical_list: D018797:Cell Cycle Proteins; C104541:STS5 protein, S pombe; D029702:Schizosaccharomyces pombe Proteins; C113424:Orb6 protein, S pombe; D017346:Protein Serine-Threonine Kinases
keywords: 14-3-3 protein; NDR kinase; P-body; RNP granule assembly; S. pombe; cell biology; polarized growth; translational repression