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Professor;
Ph.D., University of California, Berkeley, 1975

Research and Professional Interests:

Our laboratory uses 3-D electron microscopy (EM) to determine the structures of proteins and macromolecular assemblages in muscle and the cytoskeleton. Although EM is the primary data collection tool, 3-D images are computed by a variety of techniques including crystallography, single particle, helical particle and electron tomography. Electron tomography is the current emphasis. We study primarily ice embedded specimens, which preserve the structure in a native environment, but also use plastic embedded and negatively stained specimens.

One of our projects investigates the structure of myosin crossbridges in different states using the highly ordered filament lattice of insect flight muscle. Muscle specimens, while generating tension or responding to a mechanical transient, are rapidly frozen by smashing the muscle fibers against a liquid helium cooled copper block. This project is entirely done using electron tomography to obtain 3-D images and using image averaging and classification techniques to identify different states of the myosin and actin filaments into which atomic structures can be modeled.

Our laboratory is also a member of the Cell Migration Consortium which is a large scale, NIH funded collaborative project investigating the structure, regulation and function of migrating cells. Our studies in the Structure Initiative of the Consortium involve, (1) the formation of complexes of cell cell adhesion proteins using lipid monolayers as an assembly and 2-D crystallization platform, (2) cryoelectron tomography of thin margins of cells and cellular fragments, (3) integrin conformation in a membrane environment.

A third project studies the structure of smooth muscle myosin II and nonmuscle myosin V. We are investigating primarily the inactive state of these proteins using a combination of protein expression and mutagenesis and 2-D crystallization and 3-D image reconstruction. Finally, we collaborate on two projects investigating virus structure. One of these projects is studying the structure of adenoassociated virus. The other, with Prof. Ken Roux (FSU), studies the structure of HIV and SIV.

1. Jun Liu, Dianne W. Taylor and Kenneth A. Taylor. A 3-D reconstruction of smooth muscle α-actinin by cryoEM reveals two different conformations at the actin binding region. J. Mol. Biol. 338(1), 115-125 (2004). doi:10.1016/j.jmb.2004.02.034
2. Richard Tregear, Kenneth A. Taylor, Hanspeter Winkler, Mary Reedy, Yale Goldman, Clara Franzini-Armstrong, Hiro Sasaki, Carmen Lucaveche and Michael Reedy. Number and orientation of crossbri dges in target zones of active insect flight muscle. Biophys. J. 86, 3009-3019 (2004). http://www.biophysj.org/
3. Jun Liu, Mary C. Reedy, Yale E. Goldman, Clara Franzini-Armstrong, Hiroyuki Sasaki, Richard T. Tregear, Carmen Lucaveche, Hanspeter Winkler, Bruce A. J. Baumann, John M. Squire, Thomas C. Irving, Michael K. Reedy, and Kenneth A. Taylor. Electron tomography of fast frozen, stretched rigor fibers reveals elastic distortions in the myosin crossbridges. J. Struct. Biol. 147(3), 268-282 (2004). doi:10.1016/j.jsb.2004.03.008
4. Florence Tama, Michael Feig, Jun Liu, Charles L. Brooks III and Kenneth A. Taylor. The requirement for mechanical coupling between head and S2 domains in smooth muscle myosin ATPase regulati on and its implications for dimeric motor function. J. Mol. Biol. 345(4), 837-854 (2005) doi:10.1016/j.jmb.2004.10.084
5. Deborah F. Kelly and Kenneth A. Taylor. Identification of the β1-integrin binding site on α-actinin by cryo-electron microscopy. J. Struct. Biol. 149(3), 290-302 ( 2005). doi:10.1016/j.jsb.2004.11.010
6. Hanspeter Winkler and Kenneth A. Taylor. Accurate marker-free alignment with simultaneous geometry determination and reconstruction of tilt series in electron tomography. Ultramicroscopy , 106(6), 240-254 (2006). doi:10.1016/j.ultramic.2005.07.007
7. Deborah F. Kelly, Dianne W. Taylor, Constantina Bakolitsa, Andrey A. Bobkov, Laurie Bankston, Robert C. Liddington and Kenneth A Taylor. Structure of the a-actinin-vinculin head domain compl ex determined by cryo-electron microscopy J. Mol. Biol., 357(2), 562-573 (2006). doi:10.1016/j.jmb.2005.12.076
8. Jun Liu, Dianne W. Taylor, Elena Krementsova, Kathy Trybus & Kenneth A. Taylor. 3-D structure of the myosin V inhibited state by cryoelectron tomography. Nature 442, 208-211 (2006). doi:10.1038/nature04719
9. Ping Zhu, Jun Liu, Julian Bess Jr., Elena Chertova, Jeffrey D. Lifson, Henry Gris\xe9, Gilad Ofek, Kenneth A. Taylor, and Kenneth H. Roux. Distribution and three-dimensional structure of AID S virus envelope spikes. Nature 441, 847-852 (2006) doi:10.1038/nature04817
10. Jun Liu, Shenping Wu, Mary C. Reedy, Hanspeter Winkler, Carmen Lucaveche, Yifan Cheng, Michael K. Reedy, and Kenneth A. Taylor. Electron tomography of swollen rigor fibers of insect flight m uscle reveals a short and variably angled S2 domain. J. Mol. Biol. 362, 844-860 (2006) http://dx.doi.org/10.1016/j.jmb.2006.07.084
11. Kenneth A. Taylor, J. Liu & H. Winkler. Localization and classification of repetitive structures in electron tomograms of paracrystalline assemblies. In: Electron Tomography: Methods for Three-dimensional Visualization of Structures in the Cell, 2nd edition, Joachim Frank, Ed. Springer-Verlag. pp 417-439 (2006).
12. Kenneth A. Taylor. Regulation and recycling of myosin V. Curr. Opin. Cell Biol. 19(1), 67-74 (2007) http://dx.doi.org/10.1 016/j.ceb.2006.12.014
13. Cheri M. Hampton, Dianne W. Taylor and Kenneth A. Taylor. Novel structures for α-actinin: F-actin interactions and their implications for actin-membrane attachment and tension sensing in the cytoskeleton. J. Mol. Biol. 368, 92-104 (2007)
    http://dx.doi.org/10.1016/j.jmb.2007.01.071
14. Kenneth A. Taylor, S. Wu, M. C. Reedy & M. K. Reedy. Imaging actomyosin in situ. In: Methods in Cell Biology: Cellular Electron Microscopy. J. Richard McIntosh, Editor. Academic Press, San Diego, CA. pp321-368 (2007). doi:10.1016/S0091-679X(06)79013-6
15. Kenneth H. Roux & Kenneth A. Taylor. HIV envelope structure and organization. Curr. Opin. Struct. Biol. 17, 244-252 (2007) doi:10.1016/j.sbi.2007.03.008
16. Dianne W. Taylor, Deborah F. Kelly, Anchi Cheng, and Kenneth A Taylor. On the freezing of lipid monolayer specimens for cryoelectron microscopy. J. Struct. Biol. 160, 305-312 (2007) http://dx.doi.org/10.1016/j.jsb.2007.04.011
17. Wei Dai, Qingmei Jia, Eric Bortz, Sanket Shah, Jun Liu, Ivo Atanasov, Kenneth A. Taylor, Ren Sun & Z. Hong Zhou. Unique Structures in a tumor herpesvirus revealed by cryo-electron tomography and microscopy. J. Struct. Biol. (in press, 2007) doi:10.1016/j.jsb.2007.10.010

Postdoctoral Associates:

Baumann, Bruce
Hampton, Cheri
Hu, Guiqing
Huang, Zhong

Graduate Students:

Qin, Zhuan
Wu, Shenping

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