title: RNA stimulates Aurora B kinase activity during mitosis.
abstract: Accurate chromosome segregation is essential for cell viability. The mitotic spindle is crucial for chromosome segregation, but much remains unknown about factors that regulate spindle assembly. Recent work implicates RNA in promoting proper spindle assembly independently of mRNA translation; however, the mechanism by which RNA performs this function is currently unknown. Here, we show that RNA regulates both the localization and catalytic activity of the mitotic kinase, Aurora-B (AurB), which is present in a ribonucleoprotein (RNP) complex with many mRNAs. Interestingly, AurB kinase activity is reduced in Xenopus egg extracts treated with RNase, and its activity is stimulated in vitro by RNA binding. Spindle assembly defects following RNase-treatment are partially rescued by inhibiting MCAK, a microtubule depolymerase that is inactivated by AurB-dependent phosphorylation. These findings implicate AurB as an important RNA-dependent spindle assembly factor, and demonstrate a translation-independent role for RNA in stimulating AurB.
authors: Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, United States of America; Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America.
authors: Ashwini
authors: A
authors: Jambhekar
authors: Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, United States of America; Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America.
authors: Amy B
authors: AB
authors: Emerman
authors: Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, United States of America; Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America.
authors: Caterina T H
authors: CT
authors: Schweidenback
authors: Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, United States of America; Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America.
authors: Michael D
authors: MD
authors: Blower
mesh_terms: D000818:Animals; D064107:Aurora Kinase B / Q000378:metabolism*; D001483:Base Sequence; D002503:Centromere / Q000378:metabolism; D004789:Enzyme Activation; D006801:Humans; D016547:Kinesins / Q000378:metabolism; D051379:Mice; D008938:Mitosis; D021381:Protein Transport; D012313:RNA / Q000235:genetics / Q000378:metabolism*; D008941:Spindle Apparatus / Q000378:metabolism; D013379:Substrate Specificity; D029867:Xenopus Proteins / Q000378:metabolism; D014982:Xenopus laevis / Q000235:genetics / Q000378:metabolism
chemical_list: D029867:Xenopus Proteins; C509242:mitotic centromere-associated kinesin, Xenopus; D012313:RNA; D064107:Aurora Kinase B; D016547:Kinesins