title: Contractile ring-independent localization of DdINCENP, a protein important for spindle stability and cytokinesis.
abstract: Dictyostelium DdINCENP is a chromosomal passenger protein associated with centromeres, the spindle midzone, and poles during mitosis and the cleavage furrow during cytokinesis. Disruption of the single DdINCENP gene revealed important roles for this protein in mitosis and cytokinesis. DdINCENP null cells lack a robust spindle midzone and are hypersensitive to microtubule-depolymerizing drugs, suggesting that their spindles may not be stable. Furthermore DdCP224, a protein homologous to the microtubule-stabilizing protein TOGp/XMAP215, was absent from the spindle midzone of DdINCENP null cells. Overexpression of DdCP224 rescued the weak spindle midzone defect of DdINCENP null cells. Although not required for the localization of the myosin II contractile ring and subsequent formation of a cleavage furrow, DdINCENP is important for the abscission of daughter cells at the end of cytokinesis. Finally, we show that the localization of DdINCENP at the cleavage furrow is modulated by myosin II but it occurs by a mechanism different from that controlling the formation of the contractile ring.
authors.affiliation: Institute of Cellular and Molecular Biology and Department of Molecular, Cellular, and Developmental Biology, University of Texas at Austin, Austin, TX 78712, USA.
authors.forename: Qian
authors.initials: Q
authors.lastname: Chen
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.forename: Arturo
authors.initials: A
authors.lastname: De Lozanne
mesh_terms: D000818:Animals; D002460:Cell Line; D002868:Chromosomal Proteins, Non-Histone / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D003001:Cloning, Molecular; D048749:Cytokinesis / Q000502:physiology; D004023:Dictyostelium / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D008869:Microtubule-Associated Proteins / Q000032:analysis; D008938:Mitosis / Q000235:genetics / Q000502:physiology; D024462:Myosin Type II / Q000378:metabolism; D015800:Protozoan Proteins / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000032:analysis; D017386:Sequence Homology, Amino Acid; D008941:Spindle Apparatus / Q000737:chemistry / Q000378:metabolism*
chemical_list: D002868:Chromosomal Proteins, Non-Histone; D008869:Microtubule-Associated Proteins; D015800:Protozoan Proteins; D011993:Recombinant Fusion Proteins; D024462:Myosin Type II