title: The Ndc80 complex bridges two Dam1 complex rings.
abstract: Strong kinetochore-microtubule attachments are essential for faithful segregation of sister chromatids during mitosis. The Dam1 and Ndc80 complexes are the main microtubule binding components of theSaccharomyces cerevisiaekinetochore. Cooperation between these two complexes enhances kinetochore-microtubule coupling and is regulated by Aurora B kinase. We show that the Ndc80 complex can simultaneously bind and bridge across two Dam1 complex rings through a tripartite interaction, each component of which is regulated by Aurora B kinase. Mutations in any one of the Ndc80p interaction regions abrogates the Ndc80 complex's ability to bind two Dam1 rings in vitro, and results in kinetochore biorientation and microtubule attachment defects in vivo. We also show that an extra-long Ndc80 complex, engineered to space the two Dam1 rings further apart, does not support growth. Taken together, our work suggests that each kinetochore in vivo contains two Dam1 rings and that proper spacing between the rings is vital.
authors.affiliation: Department of Biochemistry, University of Washington, Seattle, United States.
authors.forename: Jae Ook
authors.identifier: 0000-0003-3500-2746
authors.initials: JO
authors.lastname: Kim
authors.affiliation: Department of Biochemistry, University of Washington, Seattle, United States.
authors.forename: Alex
authors.initials: A
authors.lastname: Zelter
authors.affiliation: Department of Biochemistry, University of Washington, Seattle, United States.
authors.forename: Neil T
authors.initials: NT
authors.lastname: Umbreit
authors.affiliation: Department of Biochemistry, University of Washington, Seattle, United States.
authors.forename: Athena
authors.initials: A
authors.lastname: Bollozos
authors.affiliation: Department of Biochemistry, University of Washington, Seattle, United States.
authors.forename: Michael
authors.initials: M
authors.lastname: Riffle
authors.affiliation: Department of Genome Sciences, University of Washington, Seattle, United States.
authors.forename: Richard
authors.initials: R
authors.lastname: Johnson
authors.affiliation: Department of Genome Sciences, University of Washington, Seattle, United States.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: MacCoss
authors.affiliation: Department of Physiology and Biophysics, University of Washington, Seattle, United States.
authors.forename: Charles L
authors.initials: CL
authors.lastname: Asbury
authors.affiliation: Department of Biochemistry, University of Washington, Seattle, United States.
authors.forename: Trisha N
authors.identifier: 0000-0003-4797-3152
authors.initials: TN
authors.lastname: Davis
mesh_terms: D064107:Aurora Kinase B / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000378:metabolism*; D020090:Chromosome Segregation; D018386:Kinetochores / Q000378:metabolism*; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D008938:Mitosis; D009687:Nuclear Proteins / Q000378:metabolism*; D011485:Protein Binding; D012441:Saccharomyces cerevisiae / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*
chemical_list: D018797:Cell Cycle Proteins; C116003:DAM1 protein, S cerevisiae; D008869:Microtubule-Associated Proteins; C112472:NDC80 protein, S cerevisiae; D009687:Nuclear Proteins; D029701:Saccharomyces cerevisiae Proteins; D064107:Aurora Kinase B
keywords: Dam1; Ndc80; S. cerevisiae; biochemistry; cell biology; kinetochore; microtubule; mitosis