The long-term goal of our research is to determine the fundamental mechanisms that regulate microtubule dynamics during diverse cellular functions. A central unanswered question is how microtubule dynamics are spatially controlled during interactions with cellular targets or attachment sites. Specifically, microtubule interactions with the cell cortex play important roles in processes such as cell polarization, cell migration, spindle positioning, and cytokinesis. Kinesin-8 is a conserved family of motor proteins and an important class of microtubule regulators essential for regulating kinetochore-microtubule dynamics and successful mitosis in human cells. Currently, the mechanism(s) used by Kinesin-8 proteins to control microtubule dynamics at cellular target sites is not clear. Budding yeast has been a productive model for elucidating mechanisms underlying microtubule interactions with the cortex. In these cells, Kinesin-8 (ScKin8) regulates cortical- microtubule interactions required to position the spindle during asymmetric cell division. ScKin8 is a dual activity motor that combines conventional motility with a plus-end specific depolymerase activity. Based on our preliminary data, we will combine yeast genetics and cell biology, live cell imaging, biochemical reconstitution, and in vitro real-time observation of dynamic microtubules by evanescent wave fluorescence microscopy to address the following Aims: 1) To define how ScKin8 alters microtubule dynamics and interactions with the cell cortex, 2) To determine how the regulatory tail domain spatially controls ScKin8 activity, and 3) To dissect the molecular features and activities of ScKin8 that underlie its biological function at the cell cortex. These findings will likely reveal conserved mechanisms and strategies used to control microtubule dynamics at other sites where Kinesin-8 functions in yeast and higher organisms.

Public Health Relevance

The spatial regulation of microtubule dynamics at cellular attachment sites is essential for biological processes such as DNA segregation, cell polarization, cell division, and thus, cell viability. The class of protein we are studying is an important regulator of microtubule dynamics in human cells. Defining the mechanisms of these proteins is critical to understanding aspects of stem cell and developmental biology, and to our ability to prevent or treat conditions such as birth defects and cancer.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM094313-04
Application #
8727046
Study Section
Nuclear and Cytoplasmic Structure/Function and Dynamics Study Section (NCSD)
Program Officer
Gindhart, Joseph G
Project Start
2011-09-01
Project End
2016-08-31
Budget Start
2014-09-01
Budget End
2015-08-31
Support Year
4
Fiscal Year
2014
Total Cost
Indirect Cost
Name
University of Chicago
Department
Genetics
Type
Schools of Medicine
DUNS #
City
Chicago
State
IL
Country
United States
Zip Code
60637
Dave, Sandeep; Anderson, Samuel J; Sinha Roy, Pallavi et al. (2018) Discrete regions of the kinesin-8 Kip3 tail differentially mediate astral microtubule stability and spindle disassembly. Mol Biol Cell 29:1866-1877
Feng, Ruizhi; Sang, Qing; Kuang, Yanping et al. (2016) Mutations in TUBB8 and Human Oocyte Meiotic Arrest. N Engl J Med 374:223-32
Rizk, Rania S; Discipio, Katherine A; Proudfoot, Kathleen G et al. (2014) The kinesin-8 Kip3 scales anaphase spindle length by suppression of midzone microtubule polymerization. J Cell Biol 204:965-75
Fukuda, Yusuke; Luchniak, Anna; Murphy, Erin R et al. (2014) Spatial control of microtubule length and lifetime by opposing stabilizing and destabilizing functions of Kinesin-8. Curr Biol 24:1826-35
Luchniak, Anna; Fukuda, Yusuke; Gupta Jr, Mohan L (2013) Structure-function analysis of yeast tubulin. Methods Cell Biol 115:355-74
Cederquist, Gustav Y; Luchniak, Anna; Tischfield, Max A et al. (2012) An inherited TUBB2B mutation alters a kinesin-binding site and causes polymicrogyria, CFEOM and axon dysinnervation. Hum Mol Genet 21:5484-99
Entwistle, Ruth A; Rizk, Rania S; Cheng, Daniel M et al. (2012) Differentiating between models of epothilone binding to microtubules using tubulin mutagenesis, cytotoxicity, and molecular modeling. ChemMedChem 7:1580-6
Lis, Lev G; Smart, Mary A; Luchniak, Anna et al. (2012) Synthesis and Biological Evaluation of a Biotinylated Paclitaxel With an Extra-Long Chain Spacer Arm. ACS Med Chem Lett 3:745-748
Su, Xiaolei; Qiu, Weihong; Gupta Jr, Mohan L et al. (2011) Mechanisms underlying the dual-mode regulation of microtubule dynamics by Kip3/kinesin-8. Mol Cell 43:751-63
Rizk, Rania S; Gupta, Mohan L (2010) Kip3 clusters kinetochores. Cell Cycle 9:2496