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Indiana University Bloomington

Claire WalczakClaire Walczak

Associate Professor, Medical Science

Office: Myers Hall 262

Phone: 812/855-5919

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Lab Website


PhD. 1993, University of Wisconsin-Madison
Post-doc, University of California- San Francisco
Professor of Biochemistry and Molecular Biology
Executive Director, IU Light Microscopy Imaging Center


The major goal of mitosis is to distribute the genetic material accurately between the two daughter cells. This process requires the mitotic spindle, which is a complex subcellular assembly composed of microtubules and associated proteins. Defects in mitosis result in aneuploidy, wherein cells receive the incorrect number of chromosomes, and is a hallmark of cancer. Therefore, understanding the mechanisms that control mitosis is of fundamental biomedical importance.

Our lab takes a multi-disciplinary approach to understanding the roles of proteins that control spindle assembly and chromosome segregation and how those proteins are both temporally and spatially regulated. We use structure/function analysis with purified proteins, biophysical analysis of single molecules, reconstitution of spindle formation using meiotic extracts from Xenopus eggs, and high-resolution live and fixed cell imaging of cells in culture. In addition, we are developing a number of high-throughput assays for the identification of small molecule inhibitors that could be used in therapeutic development.  Our approach provides a framework to decipher the molecular mechanisms of spindle assembly and chromosome segregation. Our ultimate goals are to identify new molecular targets that can be used to treat a variety of diseases in which altered microtubule activity is critical and to develop drugs that can target these regulators.


Professor of Biochemistry and Molecular Biology
Adjunct Professor of Anatomy and Cell Biology
Adjunct Professor of Biology
Member, Interdisciplinary Biochemistry Graduate Program

Awards and Honors

Leukemia and Lymphoma Scholar Award (2001)
American Cancer Society Research Scholar (2003)
Women in Cell Biology Junior Career Recognition Award from American Society for Cell Biology (2003)
Elected to ASCB  Council (2013)

Representative Publications

Rizk, R., Bohannon, K., Wetzel, L., Powers, J.A., Shaw, S.L, and Walczak, C.E. (2009). MCAK and Paclitaxel Have Differential Effects on Spindle Organization and Microtubule Dynamics. Mol. Biol. Cell. 20:1639-1651. PMID:  19158381

Cai, S., O’Connell, Khodjakov, A.  and Walczak, C.E. (2009). Chromosome Congression in the Absence of K-fibres. Nat. Cell Biol.  11: 832-838.  PMID:  19525938

Cai, S., Weaver, L.N., Ems-McClung, S.C., and Walczak, C.E. (2010). Proper Organization of Microtubule Minus-Ends is Needed for Midzone Stability and Cytokinesis.  Curr. Biol. 20:880-5. PMID: 20434340.

Stout, J.R., Yount, A.L., Powers, J.A., LeBlanc, C., Ems-McClung, S.C., and Walczak, C.E. (2011).  Kif18B Interacts with EB1 and Controls Astral Microtubule Length during Mitosis. Mol. Biol. Cell. 22:3070-3080. Epub 2011 Jul 7. PMID:21737685.

Weaver, L.N., Ems-McClung, S.C., Stout, J.R., LeBlanc, C., Shaw, S.L. Gardner, M.K., and Walczak, C.E. (2011).  Ki18A Utilizes a Microtubule Binding Site in the Tail for Plus-end Localization and Spindle Length Regulation.  Curr. Biol. 21:1500-1506. PMID: 21885282

Huang, R., Oh, H., Arrendale, A., Martin, V.A., Galan, J., Workman, E.J., Stout, J.R., Walczak, C.E., Tao, W.A., Borch, R.F., Geahlen, R.L. (2013). Intracellular Targets for a Phosphotyrosine Peptidomimetic Include the Mitotic Kinesin, MCAK.  Biochem. Pharmacol. Jul 3- epub ahead of print.  PMID 23830822

Walczak, C.E., Cai, S., and Khodjakov, A. (2010).  Chromosome Motility During Mitosis.  Nature Reviews Mol. Cell Biology.  11:  91-102 PMID: 20068571

Ems-McClung, S.C. and Walczak, C. E. (2010). Kinesin 13s in Mitosis: Key Players in the Spatial and Temporal Organization of Spindle Microtubules.  Sem. In Cell. Dev. Biology. 21:276-82. PMID: 20109574.

Walczak, C.E., Shaw S.L. (2010).  A MAP for Bundling Microtubules.  Cell. 142:364-7. PMID: 20691897.

Walczak, C.E., Rizk, R.S, and Shaw, S.L.  (2010). The Use of Fluorescence Redistribution after Photobleaching for Analysis of Cellular Microtubule Dynamics.  Methods Cell Biol. 97:35-52.  PMID: 20719264

Akhtar A, Fuchs E, Mitchison T, Shaw RJ, St Johnston D, Strasser A, Taylor S, Walczak C, Zerial M. (2011)  A Decade of Molecular Cell Biology: Achievements and Challenges. Nat. Rev. Mol. Cell Biol. 12:669-674. PMID:  21941276

Walczak, C.E., Gayek, S, and Ohi, R. (in press) Microtubule Depolymerizing Kinesins.  Annu. Rev. Cell Dev. Biol.