title: Dynein and mast/orbit/CLASP have antagonistic roles in regulating kinetochore-microtubule plus-end dynamics.
abstract: Establishment and maintenance of the mitotic spindle requires the balanced activity of microtubule-associated proteins and motors. In this study we have addressed how the microtubule plus-end tracking protein mast/orbit/CLASP and cytoplasmic dynein regulate this process in Drosophila melanogaster embryos and S2 cells. We show that mast accumulates at kinetochores early in mitosis, which is followed by a poleward streaming upon microtubule attachment. This leads to a reduction of mast levels at kinetochores during metaphase and anaphase that depends largely on the microtubule minus end-directed motor cytoplasmic dynein. Surprisingly, we also found that co-depletion of dynein rescues spindle bipolarity in mast-depleted cells, while restoring normal microtubule poleward flux. Our results suggest that mast and dynein have antagonistic roles in the local regulation of microtubule plus-end dynamics at kinetochores, which are important for the maintenance of spindle bipolarity and normal spindle length.
authors: IBMC Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto, Portugal.
authors: Rita
authors: R
authors: Reis
authors: Tália
authors: T
authors: Feijão
authors: Susana
authors: S
authors: Gouveia
authors: António J
authors: AJ
authors: Pereira
authors: Irina
authors: I
authors: Matos
authors: Paula
authors: P
authors: Sampaio
authors: Helder
authors: H
authors: Maiato
authors: Claudio E
authors: CE
authors: Sunkel
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D002460:Cell Line; D003595:Cytoplasmic Streaming; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000196:embryology / Q000235:genetics / Q000378:metabolism*; D004398:Dyneins / Q000235:genetics / Q000378:metabolism*; D018386:Kinetochores / Q000378:metabolism*; D007814:Larva / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D008938:Mitosis; D015398:Signal Transduction; D013997:Time Factors; D014162:Transfection
chemical_list: D029721:Drosophila Proteins; D008869:Microtubule-Associated Proteins; C407307:chb protein, Drosophila; D004398:Dyneins