QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

Vol. 15, Issue 5, 2312-2323, May 2004

This Article Full Text Full Text (PDF) All Versions of this Article: E03-12-0913v1 15/5/2312    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Cameron, L. A. Articles by Theriot, J. A. Search for Related Content PubMed PubMed Citation Articles by Cameron, L. A. Articles by Theriot, J. A.

Biophysical Parameters Influence Actin-based Movement, Trajectory, and Initiation in a Cell-free System

Lisa A. Cameron ^* , Jennifer R. Robbins ^* , Matthew J. Footer ^*, and Julie A. Theriot ^*  ||

^* Departments of Biochemistry, Stanford University School of Medicine, Stanford, California 94305; Microbiology and Immunology, Stanford University School of Medicine, Stanford, California 94305

Submitted December 19, 2003; Revised February 20, 2004; Accepted February 23, 2004
Monitoring Editor: Lawrence Goldstein

Using a biochemically complex cytoplasmic extract to reconstitute actin-based motility of Listeria monocytogenes and polystyrene beads coated with the bacterial protein ActA, we have systematically varied a series of biophysical parameters and examined their effects on initiation of motility, particle speed, speed variability, and path trajectory. Bead size had a profound effect on all aspects of motility, with increasing size causing slower, straighter movement and inhibiting symmetry-breaking. Speed also was reduced by extract dilution, by addition of methylcellulose, and paradoxically by addition of excess skeletal muscle actin, but it was enhanced by addition of nonmuscle (platelet) actin. Large, persistent individual variations in speed were observed for all conditions and their relative magnitude increased with extract dilution, indicating that persistent alterations in particle surface properties may be responsible for intrinsic speed variations. Trajectory curvature was increased for smaller beads and also for particles moving in the presence of methylcellulose or excess skeletal muscle actin. Symmetry breaking and movement initiation occurred by two distinct modes: either stochastic amplification of local variation for small beads in concentrated extracts, or gradual accumulation of strain in the actin gel for large beads in dilute extracts. Neither mode was sufficient to enable spherical particles to break symmetry in the cytoplasm of living cells.

Present address: Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599

Present address: Department of Biology, Xavier University, Cincinnati, OH 45207.

^|| Corresponding author. E-mail address: theriot{at}stanford.edu.

This article has been cited by other articles:

				K.-C. Lee and A. J. Liu New Proposed Mechanism of Actin-Polymerization-Driven Motility Biophys. J., November 15, 2008; 95(10): 4529 - 4539. [Abstract] [Full Text] [PDF]

				M. J. Footer, J. K. Lyo, and J. A. Theriot Close Packing of Listeria monocytogenes ActA, a Natively Unfolded Protein, Enhances F-actin Assembly without Dimerization J. Biol. Chem., August 29, 2008; 283(35): 23852 - 23862. [Abstract] [Full Text] [PDF]

				J. W. Shaevitz and D. A. Fletcher Load fluctuations drive actin network growth PNAS, October 2, 2007; 104(40): 15688 - 15692. [Abstract] [Full Text] [PDF]

				M. J. Footer, J. W. J. Kerssemakers, J. A. Theriot, and M. Dogterom Direct measurement of force generation by actin filament polymerization using an optical trap PNAS, February 13, 2007; 104(7): 2181 - 2186. [Abstract] [Full Text] [PDF]

				F. S. Soo and J. A. Theriot Adhesion controls bacterial actin polymerization-based movement PNAS, November 8, 2005; 102(45): 16233 - 16238. [Abstract] [Full Text] [PDF]

				S. M. Rafelski and J. A. Theriot Bacterial Shape and ActA Distribution Affect Initiation of Listeria monocytogenes Actin-Based Motility Biophys. J., September 1, 2005; 89(3): 2146 - 2158. [Abstract] [Full Text] [PDF]

				A. Bernheim-Groswasser, J. Prost, and C. Sykes Mechanism of Actin-Based Motility: A Dynamic State Diagram Biophys. J., August 1, 2005; 89(2): 1411 - 1419. [Abstract] [Full Text] [PDF]

				F. S. Soo and J. A. Theriot Large-Scale Quantitative Analysis of Sources of Variation in the Actin Polymerization-Based Movement of Listeria monocytogenes Biophys. J., July 1, 2005; 89(1): 703 - 723. [Abstract] [Full Text] [PDF]

				P. T. Yam and J. A. Theriot Repeated Cycles of Rapid Actin Assembly and Disassembly on Epithelial Cell Phagosomes Mol. Biol. Cell, December 1, 2004; 15(12): 5647 - 5658. [Abstract] [Full Text] [PDF]

				G. Gerisch, T. Bretschneider, A. Muller-Taubenberger, E. Simmeth, M. Ecke, S. Diez, and K. Anderson Mobile Actin Clusters and Traveling Waves in Cells Recovering from Actin Depolymerization Biophys. J., November 1, 2004; 87(5): 3493 - 3503. [Abstract] [Full Text] [PDF]