Dr. Claire Walczak

Professor of Biochemistry and Molecular Biology
Executive Director, IU Light Microscopy Imaging Center

Research Interests

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. 



Selected Publications

  • Walczak, C.E., Gayek, S, and Ohi, R. (in press) Microtubule Depolymerizing Kinesins.  Annu. Rev. Cell Dev. Biol.  
  • 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., 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
  • Walczak, C.E., Shaw S.L. (2010).  A MAP for Bundling Microtubules.  Cell. 142:364-7. PMID: 20691897.
  • 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., Cai, S., and Khodjakov, A. (2010).  Chromosome Motility During Mitosis.  Nature Reviews Mol. Cell Biology.  11:  91-102 PMID: 20068571
  • 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
  • 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
  • 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.
  • 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.
  • 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
  • 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

Awards and Honors

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


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

  • NEWS
  • Microenvironment-induced downregulation of miR-193b drives ovarian cancer metastasis

    Apr 28th, 2015

    Anirban K Mitra, Assistant Professor of Medical and Molecular Genetics has recently published his research in Oncogene. His study links paracrine signals from the microenvironment to the regulation of a key miRNA - miR-193b - in ovarian cancer cells, which promotes metastatic colonization.

    New link between motor proteins and breast cancer

    Apr 21th, 2015

    Collaborative work between Claire Walczak (Medical Sciences) and Ritu Aneja (Georgia Tech) reveals that overexpression of the mitotic kinesin, HSET, promotes tumor progression.

    American Cancer Society awards Research Scholar Grant to Dr. Heather Hundley

    Apr 21th, 2015

    Heather A. Hundley, Assistant Professor of Biochemistry and Molecular Biology, has been awarded a $775,000 grant from the American Cancer Society to support her project “Mechanisms Regulating RNA Editing at Specific Sites in the Transcriptome.”


    Comparison of MAPK specificity across the ETS transcription factor family identifies a high-affinity ERK interaction required for ERG function in prostate cells

    Selvaraj N, Kedage V, Hollenhorst PC

    ERK signaling regulates the opposing roles of JUN family transcription factors at ETS/AP-1 sites and in cell migration

    Selvaraj N, Budka JA, Ferris MW, Plotnik JP, Hollenhorst PC

    Regulatory mechanisms that control mitotic kinesins

    Yount AL, Zong H, Walczak CE

  • Peter Hollenhorst, PhD

    Aug. 31, 4pm JH 009

    Assistant Professor of Biochemistry and Molecular Biology Medical Sciences Program,
    Indiana University Bloomington, IN

    Lindsey D. Mayo, PhD

    Sept. 14, 4pm JH 009

    Associate Professor of Pediatrics
    Associate Professor of Biochemistry and Molecular Biology Wells Center for Pediatric Research
    Indianapolis, IN

    Charles N. Landen Jr, MD

    Sept. 21, 4pm JH 009

    Associate Professor
    Department of Obstetrics and Gynecology
    University of Virginia Cancer Center

    Qianben Wang, PhD

    Sept. 28, 4pm JH 009

    Associate Professor
    Department of Molecular Virology, Immunology and Medical Genetics and the Comprehensive Cancer Center
    College of Medicine the Ohio State University

  • CME conference

    Ethical Decisions for End of Life Care

    Wednesday, Jul 8th

    Shawn Gerber, M.Div.
    BCC Director, Spiritual Care & Chaplaincy IU Health Bloomington
    Bloomington, IN

    Pediatric Trauma

    Friday, Jul 10th

    Yueh Chang Ho, MD
    Assistant Prof. of Radiology
    Indianapolis, IN

    Carpal Tunnel Syndrome

    Wednesday, Jul 15th

    Otto Wickstrom, MD
    IU Health Southern Indiana Physicians
    Orthopedics & Sports Medicine
    Bloomington, IN

    Personalized Medicine: Challenges to Patients & their Physicians

    Friday, Jul 24th

    Kenneth Cornetta, MD
    IU Dept. of Medical & Molecular Genetics

    The Increasing Complexity of Venous Thromboembolic Disease

    Friday, Jul 31st

    Kenneth Cornetta, MD
    David Hedrick, MD

    Indiana Hemophilia & Thrombosis Center
    Indianapolis, IN

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