The transmission of genetic material in each cell division requires its accurate duplication and distribution to the daughter cells. Errors in this process lead to aneuploidy, which is implicated in oncogenesis, disability and cell death. The chromosomes are segregated into two equivalent parts by a microtubule-based molecular machine, the mitotic spindle. The spindle is bipolar with each pole carrying an exact complement of chromosomes to each daughter cell. Spindle morphogenesis requires spatially controlled microtubule nucleation. The small gamma-tubulin complex is required for nucleation but is surprisingly inactive in isolated form. Our recent structural advances make a strong prediction for how the complex could be activated, which we will test by a mutational analysis. Moreover we will identify components or modifications of the complex that activate and regulate nucleation. Chromosomes attach to microtubules via kinetochores, multiprotein organelles that span from the DNA to the microtubule. This connection is carefully orchestrated and controls both the movement and organization of chromosomes to ensure proper segregation. Kinetochores perform the surprising feat of maintaining strong persistent attachments to microtubules even during the addition and removal of thousand of tubulin subunits. We will continue our reconstitution of the kinetochore from component parts to understand the molecular mechanism and regulation underlying this attachment.

Public Health Relevance

The transmission of genetic material in each cell division requires its accurate duplication and distribution to the daughter cells. Errors in this process lead to aneuploidy, which is implicated in oncogenesis, disability and cell death.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM040506-24
Application #
8425051
Study Section
Nuclear and Cytoplasmic Structure/Function and Dynamics Study Section (NCSD)
Program Officer
Deatherage, James F
Project Start
1988-07-01
Project End
2015-01-31
Budget Start
2013-02-01
Budget End
2014-01-31
Support Year
24
Fiscal Year
2013
Total Cost
$501,499
Indirect Cost
$171,380
Name
University of Washington
Department
Biochemistry
Type
Schools of Medicine
DUNS #
605799469
City
Seattle
State
WA
Country
United States
Zip Code
98195
Hsia, Yang; Bale, Jacob B; Gonen, Shane et al. (2016) Design of a hyperstable 60-subunit protein icosahedron. Nature 535:136-9
Zelter, Alex; Bonomi, Massimiliano; Kim, Jae ook et al. (2015) The molecular architecture of the Dam1 kinetochore complex is defined by cross-linking based structural modelling. Nat Commun 6:8673
Kollman, Justin M; Greenberg, Charles H; Li, Sam et al. (2015) Ring closure activates yeast γTuRC for species-specific microtubule nucleation. Nat Struct Mol Biol 22:132-7
Kudalkar, Emily M; Scarborough, Emily A; Umbreit, Neil T et al. (2015) Regulation of outer kinetochore Ndc80 complex-based microtubule attachments by the central kinetochore Mis12/MIND complex. Proc Natl Acad Sci U S A 112:E5583-9
Tien, Jerry F; Umbreit, Neil T; Zelter, Alex et al. (2014) Kinetochore biorientation in Saccharomyces cerevisiae requires a tightly folded conformation of the Ndc80 complex. Genetics 198:1483-93
Umbreit, Neil T; Miller, Matthew P; Tien, Jerry F et al. (2014) Kinetochores require oligomerization of Dam1 complex to maintain microtubule attachments against tension and promote biorientation. Nat Commun 5:4951
Tien, Jerry F; Fong, Kimberly K; Umbreit, Neil T et al. (2013) Coupling unbiased mutagenesis to high-throughput DNA sequencing uncovers functional domains in the Ndc80 kinetochore protein of Saccharomyces cerevisiae. Genetics 195:159-70
Umbreit, Neil T; Gestaut, Daniel R; Tien, Jerry F et al. (2012) The Ndc80 kinetochore complex directly modulates microtubule dynamics. Proc Natl Acad Sci U S A 109:16113-8
Umbreit, Neil T; Davis, Trisha N (2012) Mitosis puts sisters in a strained relationship: force generation at the kinetochore. Exp Cell Res 318:1361-6
Asbury, Charles L; Tien, Jerry F; Davis, Trisha N (2011) Kinetochores' gripping feat: conformational wave or biased diffusion? Trends Cell Biol 21:38-46

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