A hallmark of cancer is uncontrolled cell division, and many cancers therapeutic measures work by disrupting microtubule dynamics and/or mitotic spindle architecture to arrest cell division. It is clear that proper microtubule organization and length regulation are important for the successful completion of cell division. In this study, we will focus on mechanisms for how microtubule-associated proteins regulate microtubule lengths and organize spindle microtubules during mitosis. To provide a basis for these and future studies, we will first focus on microtubule dynamics in the absence of regulating proteins to better understand the relationship between microtubule tip structures and microtubule dynamics. Our preliminary modeling results predict that microtubule tip structures are important for self-regulating microtubule dynamics. We will investigate this hypothesis using in-vitro fluorescence and electron microscopy, as well as in-vivo analysis in budding yeast. Then, we will investigate the mechanism for tip-tracking of important microtubule plus end-binding proteins, such as Eb1, to determine whether the microtubule tip structures could provide a platform for targeting of important length-regulating proteins to the microtubule tip. Finally, we will investigate the role of microtubule- associated proteins in organizing microtubules into a mitotic spindle during cell division. Specifically, we will use in-vivo experiments in budding yeas cells, in-vitro reconstitution, and computer simulations to determine the role and mechanism of Kinesin-14 minus-end directed motors in establishing proper microtubule bundling in mitotic spindles.

Public Health Relevance

A hallmark of cancer is uncontrolled cell division. In this proposal, we will study the mechanisms that regulate and control cell division. Therefore, this work will help us to better understand the mechanism of current cancer therapies, and also provide potential drug targets for new therapies.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM103833-02
Application #
8666658
Study Section
Modeling and Analysis of Biological Systems Study Section (MABS)
Program Officer
Swain, Amy L
Project Start
2013-06-01
Project End
2018-05-31
Budget Start
2014-06-01
Budget End
2015-05-31
Support Year
2
Fiscal Year
2014
Total Cost
$277,313
Indirect Cost
$87,313
Name
University of Minnesota Twin Cities
Department
Genetics
Type
Schools of Medicine
DUNS #
555917996
City
Minneapolis
State
MN
Country
United States
Zip Code
55455
Prahl, Louis S; Castle, Brian T; Gardner, Melissa K et al. (2014) Quantitative analysis of microtubule self-assembly kinetics and tip structure. Methods Enzymol 540:35-52
Hepperla, Austin J; Willey, Patrick T; Coombes, Courtney E et al. (2014) Minus-end-directed Kinesin-14 motors align antiparallel microtubules to control metaphase spindle length. Dev Cell 31:61-72