The kinetochore is a network of protein complexes that assembles on centromeric chromatin to act as the connection point between chromosomes and the microtubules that segregate them into daughter cells. During anaphase kinetochores allow chromosomes to track the depolymerizing ends of microtubules, which are the primary site of force generation. Thus, kinetochores not only do not let go of microtubule ends as they breakdown, but are able to harness the energy stored in the microtubule lattice and released during depolymerization to produce processive movement of chromosomes to the spindle poles. In this proposal we aim to probe the molecular mechanisms of directed chromosome motion by examining a set of kinetochore protein complexes that are the site of microtubule attachment. Our approach is to combine activity assays, electron microscopy and image analysis, and bioinformatic methods, in the characterization of fully functional complexes. We are studying the yeast-specific DAM1 complex, which assembles in a microtubule-dependent manner into a ring structure that is able to diffuse on the microtubule surface and to track depolymerizing ends. We are also characterizing the conserved NDC80 complex, and the complete KMN network in yeast, which includes also the MTW1 complex and Spc105. Our ultimate objective is to gain a mechanistic understanding of the molecular interactions governing the dynamic attachment of kinetochores to microtubules. Our structural models would be further tested with our collaborators using the powerful yeast system.

Public Health Relevance

Our overall goal is to gain a mechanistic understanding of the molecular interactions governing the regulated, dynamic attachment of kinetochores to microtubules that underlies the accurate segregation of chromosomes during mitosis. Misregulation of this essential process leads to aneuploidy and tumorigenesis.

Agency
National Institute of Health (NIH)
Type
Research Program Projects (P01)
Project #
5P01GM051487-19
Application #
8666760
Study Section
Special Emphasis Panel (ZRG1)
Project Start
Project End
Budget Start
Budget End
Support Year
19
Fiscal Year
2014
Total Cost
Indirect Cost
Name
Lawrence Berkeley National Laboratory
Department
Type
DUNS #
City
Berkeley
State
CA
Country
United States
Zip Code
94720
Han, Bong-Gyoon; Watson, Zoe; Kang, Hannah et al. (2016) Long shelf-life streptavidin support-films suitable for electron microscopy of biological macromolecules. J Struct Biol 195:238-44
Hurley, James H; Nogales, Eva (2016) Next-generation electron microscopy in autophagy research. Curr Opin Struct Biol 41:211-216
Borisy, Gary; Heald, Rebecca; Howard, Jonathon et al. (2016) Microtubules: 50 years on from the discovery of tubulin. Nat Rev Mol Cell Biol 17:322-8
Kellogg, Elizabeth H; Howes, Stuart; Ti, Shih-Chieh et al. (2016) Near-atomic cryo-EM structure of PRC1 bound to the microtubule. Proc Natl Acad Sci U S A 113:9430-9
Sun, Jing; Jiang, Xi; Lund, Reidar et al. (2016) Self-assembly of crystalline nanotubes from monodisperse amphiphilic diblock copolypeptoid tiles. Proc Natl Acad Sci U S A 113:3954-9
Berleman, James E; Zemla, Marcin; Remis, Jonathan P et al. (2016) Exopolysaccharide microchannels direct bacterial motility and organize multicellular behavior. ISME J 10:2620-2632
Young, Lindsey N; Cho, Kelvin; Lawrence, Rosalie et al. (2016) Dynamics and architecture of the NRBF2-containing phosphatidylinositol 3-kinase complex I of autophagy. Proc Natl Acad Sci U S A 113:8224-9
Shamir, Eliah R; Coutinho, Kester; Georgess, Dan et al. (2016) Twist1-positive epithelial cells retain adhesive and proliferative capacity throughout dissemination. Biol Open 5:1216-28
Jiang, Fuguo; Taylor, David W; Chen, Janice S et al. (2016) Structures of a CRISPR-Cas9 R-loop complex primed for DNA cleavage. Science 351:867-71
Sun, Jing; Jiang, Xi; Siegmund, Aaron et al. (2016) Morphology and Proton Transport in Humidified Phosphonated Peptoid Block Copolymers. Macromolecules 49:3083-3090

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