title: Spatiotemporal regulation of Ipl1/Aurora activity by direct Cdk1 phosphorylation.
abstract: Oscillating cyclin-dependent kinase 1 (Cdk1) activity is the major regulator of cell-cycle progression, whereas the Aurora B kinase, as part of the chromosome passenger complex (CPC), controls critical aspects of mitosis such as chromosome condensation and biorientation on the spindle. How these kinases mechanistically coordinate their important functions is only partially understood. Here, using budding yeast, we identify a regulatory mechanism by which the Cdk1 kinase Cdc28 directly controls the Aurora kinase Ipl1. We show that Cdk1 phosphorylates Ipl1 on two serine residues in the N-terminal domain, thereby suppressing its association with the microtubule plus-end tracking protein Bim1 until the onset of anaphase. Failure to phosphorylate Ipl1 leads to its premature targeting to the metaphase spindle and results in constitutive Bim1 phosphorylation, which is normally restricted to anaphase. Cells expressing an Ipl1-Sli15 complex that cannot be phosphorylated by Cdk1 display a severe growth defect. Our work shows that Ipl1/Aurora is not only the catalytic subunit of the CPC but also an important regulatory target that allows Cdk1 to coordinate chromosome biorientation with spindle morphogenesis.
authors.affiliation: Research Institute of Molecular Pathology, Dr. Bohr-Gasse 7, 1030 Vienna, Austria.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Zimniak
authors.forename: Veronika
authors.initials: V
authors.lastname: Fitz
authors.forename: Hongwen
authors.initials: H
authors.lastname: Zhou
authors.forename: Fabienne
authors.initials: F
authors.lastname: Lampert
authors.forename: Susanne
authors.initials: S
authors.lastname: Opravil
authors.forename: Karl
authors.initials: K
authors.lastname: Mechtler
authors.forename: Peggy
authors.initials: P
authors.lastname: Stolt-Bergner
authors.forename: Stefan
authors.initials: S
authors.lastname: Westermann
mesh_terms: D064127:Aurora Kinases; D016203:CDC2 Protein Kinase / Q000378:metabolism*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*
chemical_list: D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases; D016203:CDC2 Protein Kinase