title: Midzone activation of aurora B in anaphase produces an intracellular phosphorylation gradient.
abstract: Proper partitioning of the contents of a cell between two daughters requires integration of spatial and temporal cues. The anaphase array of microtubules that self-organize at the spindle midzone contributes to positioning the cell-division plane midway between the segregating chromosomes. How this signalling occurs over length scales of micrometres, from the midzone to the cell cortex, is not known. Here we examine the anaphase dynamics of protein phosphorylation by aurora B kinase, a key mitotic regulator, using fluorescence resonance energy transfer (FRET)-based sensors in living HeLa cells and immunofluorescence of native aurora B substrates. Quantitative analysis of phosphorylation dynamics, using chromosome- and centromere-targeted sensors, reveals that changes are due primarily to position along the division axis rather than time. These dynamics result in the formation of a spatial phosphorylation gradient early in anaphase that is centred at the spindle midzone. This gradient depends on aurora B targeting to a subpopulation of microtubules that activate it. Aurora kinase activity organizes the targeted microtubules to generate a structure-based feedback loop. We propose that feedback between aurora B kinase activation and midzone microtubules generates a gradient of post-translational marks that provides spatial information for events in anaphase and cytokinesis.
authors.affiliation: Department of Biochemistry, University of Virginia School of Medicine, Charlottesville, Virginia 22908, USA.
authors.forename: Brian G
authors.initials: BG
authors.lastname: Fuller
authors.forename: Michael A
authors.initials: MA
authors.lastname: Lampson
authors.forename: Emily A
authors.initials: EA
authors.lastname: Foley
authors.forename: Sara
authors.initials: S
authors.lastname: Rosasco-Nitcher
authors.forename: Kim V
authors.initials: KV
authors.lastname: Le
authors.forename: Page
authors.initials: P
authors.lastname: Tobelmann
authors.forename: David L
authors.initials: DL
authors.lastname: Brautigan
authors.forename: P Todd
authors.initials: PT
authors.lastname: Stukenberg
authors.forename: Tarun M
authors.initials: TM
authors.lastname: Kapoor
mesh_terms: D000705:Anaphase / Q000502:physiology*; D000818:Animals; D064107:Aurora Kinase B; D064127:Aurora Kinases; D002451:Cell Compartmentation; D002503:Centromere / Q000378:metabolism; D002843:Chromatin / Q000378:metabolism; D004789:Enzyme Activation; D031541:Fluorescence Resonance Energy Transfer; D006367:HeLa Cells; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D008941:Spindle Apparatus / Q000378:metabolism; D014981:Xenopus
chemical_list: D002843:Chromatin; C576921:AURKB protein, human; D064107:Aurora Kinase B; D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases