The broad goal of this project is to understand how dynamic microtubules are controlled during cell division to build the mitotic spindle and to segregate chromosomes with high fidelity. This project is designed to investigate the mechanism by which mitotic microtubule motor proteins of the kinesin family regulate microtubule dynamics in order to facilitate mitotic spindle assembly, chromosome segregation and long-term stability of chromosome number. Our approach is interdisciplinary, ranging from single molecule biophysical analyses using total internal reflection microscopy (TIRF) and purified components to cellular approaches using high resolution quantitative live cell imaging, mutant constructs and siRNA depletions. We will use TIRF microscopy of live microtubules at physiological temperature and buffer conditions to evaluate the effect of mitotic kinesins on microtubule assembly and disassembly. Armed with an understanding of the activity the motor provides to microtubules in isolation we will transfer our studies to live mitotic cells. Using hig resolution imaging, selective depletions of kinesins and mutant analogs we will evaluate how kinesin motor activity is used within the mitotic spindle. This is essential basic knowledge which will guide the development of drugs targeted to mitotic kinesins for use in cancer treatment. Finally, we have preliminary evidence that small alterations in microtubule dynamics that do not have a profound impact on cell division in the short term have significant effects on long-term chromosome instability. Furthermore, known tumor suppressor genes which have not previously been linked to microtubules may exhibit unexpected direct or indirect effects on microtubule dynamics. We have a simple visual screen that will provide us with a panel of genes implicated in microtubule dynamics alterations and, by extension, chromosome instability. This will assist in molecular characterization of cancers and targeted drug development. Using these approaches we will learn how motile kinesins target to and regulate polymer assembly and disassembly at microtubule ends and what effect alterations in microtubule dynamics has on short-term spindle assembly and chromosome segregation. This project is designed to evaluate the effect that small changes in microtubule dynamics in the mitotic spindle has on chromosome instability and, in this way, understand the mechanistic forces underlying tumor progression.
During cell division chromosomes must be segregated to each daughter cell with perfect fidelity to avoid the alterations in chromosome numbers characteristic of cancer cells. This process is critically dependent on dynamic polymers within the cell called microtubules and cells have evolved numerous motor molecules that regulate microtubule assembly and disassembly. By investigating the mechanism of action of these regulators we will uncover new, tissue-specific targets for cancer therapies and increase our understanding of the molecular events that drive cell division in normal and cancer cells.
|Decarreau, Justin; Driver, Jonathan; Asbury, Charles et al. (2014) Rapid measurement of mitotic spindle orientation in cultured mammalian cells. Methods Mol Biol 1136:31-40|
|Ertych, Norman; Stolz, Ailine; Stenzinger, Albrecht et al. (2014) Increased microtubule assembly rates influence chromosomal instability in colorectal cancer cells. Nat Cell Biol 16:779-91|
|Schumpert, Brenda; Garcia, Maria Guadalupe; Wessel, Gary M et al. (2013) Roles for focal adhesion kinase (FAK) in blastomere abscission and vesicle trafficking during cleavage in the sea urchin embryo. Mech Dev 130:290-303|
|Earnshaw, W C; Allshire, R C; Black, B E et al. (2013) Esperanto for histones: CENP-A, not CenH3, is the centromeric histone H3 variant. Chromosome Res 21:101-6|
|Domnitz, Sarah B; Wagenbach, Michael; Decarreau, Justin et al. (2012) MCAK activity at microtubule tips regulates spindle microtubule length to promote robust kinetochore attachment. J Cell Biol 197:231-7|
|Logue, Jeremy S; Whiting, Jennifer L; Tunquist, Brian et al. (2011) AKAP220 protein organizes signaling elements that impact cell migration. J Biol Chem 286:39269-81|
|Stumpff, Jason; Du, Yaqing; English, Chauca A et al. (2011) A tethering mechanism controls the processivity and kinetochore-microtubule plus-end enrichment of the kinesin-8 Kif18A. Mol Cell 43:764-75|
|Mattison, Christopher P; Stumpff, Jason; Wordeman, Linda et al. (2011) Mip1 associates with both the Mps1 kinase and actin, and is required for cell cortex stability and anaphase spindle positioning. Cell Cycle 10:783-93|
|Rankin, Kathleen E; Wordeman, Linda (2010) Long astral microtubules uncouple mitotic spindles from the cytokinetic furrow. J Cell Biol 190:35-43|
|Wordeman, Linda (2010) How kinesin motor proteins drive mitotic spindle function: Lessons from molecular assays. Semin Cell Dev Biol 21:260-8|
Showing the most recent 10 out of 30 publications