Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 16 June 2000:
Vol. 288. no. 5473, pp. 2035 - 2039
DOI: 10.1126/science.288.5473.2035
Prev | Table of Contents | Next

Reports

Hierarchical Self-Assembly of F-Actin and Cationic Lipid Complexes: Stacked Three-Layer Tubule Networks

Gerard C. L. Wong, 1* Jay X. Tang, 2dagger Alison Lin, 1 Youli Li, 1 Paul A. Janmey, 2ddagger Cyrus R. Safinya 1§

We describe a distinct type of spontaneous hierarchical self-assembly of cytoskeletal filamentous actin (F-actin), a highly charged polyelectrolyte, and cationic lipid membranes. On the mesoscopic length scale, confocal microscopy reveals ribbonlike tubule structures that connect to form a network of tubules on the macroscopic scale (more than 100 micrometers). Within the tubules, on the 0.5- to 50-nanometer length scale, x-ray diffraction reveals an unusual structure consisting of osmotically swollen stacks of composite membranes with no direct analog in simple amphiphilic systems. The composite membrane is composed of three layers, a lipid bilayer sandwiched between two layers of actin, and is reminiscent of multilayered bacterial cell walls that exist far from equilibrium. Electron microscopy reveals that the actin layer consists of laterally locked F-actin filaments forming an anisotropic two-dimensional tethered crystal that appears to be the origin of the tubule formation.

1 Materials Department, Physics Department, and Biochemistry and Molecular Biology Program, University of California, Santa Barbara, CA 93106, USA.
2 Division of Experimental Medicine, Brigham and Women's Hospital, Harvard University, Boston, MA 02115, USA.
*   Present address: Department of Materials Science and Engineering and Department of Physics, University of Illinois, Urbana-Champagne, IL 61801, USA.

dagger    Present address: Department of Physics, Indiana University, Bloomington, IN 47405, USA.

ddagger    Present address: Department of Physiology, Institute for Medicine/Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA.

§   To whom correspondence should be addressed. E-mail: safinya{at}mrl.ucsb.edu

Read the Full Text


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
In vitro self-assembly of tailorable nanotubes from a simple protein building block.
E. R. Ballister, A. H. Lai, R. N. Zuckermann, Y. Cheng, and J. D. Mougous (2008)
PNAS 105, 3733-3738
   Abstract »    Full Text »    PDF »
The directed cooperative assembly of proteorhodopsin into 2D and 3D polarized arrays.
H. Liang, G. Whited, C. Nguyen, and G. D. Stucky (2007)
PNAS 104, 8212-8217
   Abstract »    Full Text »    PDF »
Cationic liposome-DNA complexes: from liquid crystal science to gene delivery applications.
C. R Safinya, K. Ewert, A. Ahmad, H. M Evans, U. Raviv, D. J Needleman, A. J Lin, N. L Slack, C. George, and C. E Samuel (2006)
Phil Trans R Soc A 364, 2573-2596
   Abstract »    Full Text »    PDF »
Anionic poly(amino acid)s dissolve F-actin and DNA bundles, enhance DNase activity, and reduce the viscosity of cystic fibrosis sputum.
J. X. Tang, Q. Wen, A. Bennett, B. Kim, C. A. Sheils, R. Bucki, and P. A. Janmey (2005)
Am J Physiol Lung Cell Mol Physiol 289, L599-L605
   Abstract »    Full Text »    PDF »
Cationic liposome-microtubule complexes: Pathways to the formation of two-state lipid-protein nanotubes with open or closed ends.
U. Raviv, D. J. Needleman, Y. Li, H. P. Miller, L. Wilson, and C. R. Safinya (2005)
PNAS 102, 11167-11172
   Abstract »    Full Text »    PDF »
Toroidal Triblock Copolymer Assemblies.
D. J. Pochan, Z. Chen, H. Cui, K. Hales, K. Qi, and K. L. Wooley (2004)
Science 306, 94-97
   Abstract »    Full Text »    PDF »
Supramolecular Self-Assembly of Macroscopic Tubes.
D. Yan, Y. Zhou, and J. Hou (2004)
Science 303, 65-67
   Abstract »    Full Text »    PDF »
DNA condensation in two dimensions.
I. Koltover, K. Wagner, and C. R. Safinya (2000)
PNAS 97, 14046-14051
   Abstract »    Full Text »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)