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)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Program Projects (P01)
Project #
5P01GM051487-18
Application #
8486444
Study Section
Special Emphasis Panel (ZRG1-CB-B)
Project Start
Project End
Budget Start
2013-06-01
Budget End
2014-05-31
Support Year
18
Fiscal Year
2013
Total Cost
$335,125
Indirect Cost
$190,278
Name
Lawrence Berkeley National Laboratory
Department
Type
DUNS #
078576738
City
Berkeley
State
CA
Country
United States
Zip Code
94720
Zhang, Rui; LaFrance, Benjamin; Nogales, Eva (2018) Separating the effects of nucleotide and EB binding on microtubule structure. Proc Natl Acad Sci U S A 115:E6191-E6200
Nogales, Eva (2018) Cytoskeleton in high resolution. Nat Rev Mol Cell Biol 19:142
Downing, Kenneth H; Glaeser, Robert M (2018) Estimating the effect of finite depth of field in single-particle cryo-EM. Ultramicroscopy 184:94-99
Nogales, Eva (2018) Cryo-EM. Curr Biol 28:R1127-R1128
Sazzed, Salim; Song, Junha; Kovacs, Julio A et al. (2018) Tracing Actin Filament Bundles in Three-Dimensional Electron Tomography Density Maps of Hair Cell Stereocilia. Molecules 23:
Kamennaya, Nina A; Zemla, Marcin; Mahoney, Laura et al. (2018) High pCO2-induced exopolysaccharide-rich ballasted aggregates of planktonic cyanobacteria could explain Paleoproterozoic carbon burial. Nat Commun 9:2116
Howes, Stuart C; Geyer, Elisabeth A; LaFrance, Benjamin et al. (2018) Structural and functional differences between porcine brain and budding yeast microtubules. Cell Cycle 17:278-287
Glaeser, Robert M (2018) PROTEINS, INTERFACES, AND CRYO-EM GRIDS. Curr Opin Colloid Interface Sci 34:1-8
Kellogg, Elizabeth H; Hejab, Nisreen M A; Poepsel, Simon et al. (2018) Near-atomic model of microtubule-tau interactions. Science 360:1242-1246
Zhang, Rui; Roostalu, Johanna; Surrey, Thomas et al. (2017) Structural insight into TPX2-stimulated microtubule assembly. Elife 6:

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