Jun Liu

NIH NCI/CCR
50 South Drive Rm 4306 MSC 8008
Bethesda MD 20892-8008
Web page
E-Mail:liujun@mail.nih.gov

I was a post-doc in the lab from 1998 through March of 2006. I worked on 3D reconstruction of chicken smooth muscle α-actinin by cryo-electron microscopy. A 3D atomic model of α-actinin was builted and refined against the 3D EM density map with 2.0nm resolution. To demonstrate how the α-actinin is cross-linked with F-actin, a tilted series of F-actin bundles was collected on Philips CM300-FEG electron microscope from -70 degree to +70 degree. Electron tomography was applied to generate the 3D structure of F-actin bundles. This project is an important step to demostrate the 3D structure of α-actinin and its structural relationship with F-actin. Other structures I have worked on are insect flight muscle, the IOS structure, full length smooth muscle myosin, the inhibited conformation of myosin-V, and the the envelope spikes of SIV and HIV.

Here are some models of the α-actinin structure I worked with.

Bipolar	Polar

PUBLICATIONS

Jun Liu, Thomas Wendt, Dianne W. Taylor and Kenneth A. Taylor. Refined model of the 10S conformation of smooth muscle myosin by cryoEM 3-D image reconstruction. J. Mol. Biol. 329(5), 963-972 (2003).
Ping Zhu, Elena Chertova, Julian Bess, Jr., Jeffrey D. Lifson, Larry O. Arthur, Jun Liu, Kenneth A. Taylor, and Kenneth H. Roux. Electron tomography analysis of envelope glycoprotein trimers on HIV and simian immunodeficiency virus virions. Proc. Natl. Acad. Sci. 100(26), 15812-15817 (2003).
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).
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).
Jun Liu, Dianne W. Taylor and Kenneth A. Taylor. A 3-D reconstruction of smooth muscle alpha-actinin by cryoEM reveals two different conformations at the actin binding region. J. Mol. Biol. 338(1), 115-125 (2004).
Ping Zhu, Jun Liu, Julian Bess Jr., Elena Chertova, Jeffrey D. Lifson, Henry Gris, Gilad Ofek, Kenneth A. Taylor, and Kenneth H. Roux. Distribution and three-dimensional structure of AIDS virus envelope spikes. Nature 441, 847-852 (2006).
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).
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 muscle reveals a short and variably angled S2 domain. J. Mol. Biol. 362, 844-860 (2006).
K. 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).
Hanspeter Winkler, Jun Liu, Kenneth A. Taylor, Ping Zhu, Kenneth H. Roux. Electron tomography of macromolecular assemblies. In: Proceedings of the 4th IEEE International Symposium on Biomedical Imaging: From Nano to Macro, pg 240-243 (2007).
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. 161, 428-438 (2008).
Feng Ye, Jun Liu, Hanspeter Winkler and Kenneth A. Taylor. Integrin α IIbΒ3 in a membrane environment remains the same height after Mn⁺⁺ activation when observed by cryo-electron tomography. J. Mol. Biol., (in press, 2008).