Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
Biophys J
2005 Jan 01;881:680-9. doi: 10.1529/biophysj.104.048025.
Show Gene links
Show Anatomy links
Mechanical properties of Xenopus egg cytoplasmic extracts.
Valentine MT
,
Perlman ZE
,
Mitchison TJ
,
Weitz DA
.
???displayArticle.abstract???
Cytoplasmic extracts prepared from Xenopus laevis eggs are used for the reconstitution of a wide range of processes in cell biology, and offer a unique environment in which to investigate the role of cytoplasmic mechanics without the complication of preorganized cellular structures. As a step toward understanding the mechanical properties of this system, we have characterized the rheology of crude interphase extracts. At macroscopic length scales, the extract forms a soft viscoelastic solid. Using a conventional mechanical rheometer, we measure the elastic modulus to be in the range of 2-10 Pa, and loss modulus in the range of 0.5-5 Pa. Using pharmacological and immunological disruption methods, we establish that actin filaments and microtubules cooperate to give mechanical strength, whereas the intermediate filament cytokeratin does not contribute to viscoelasticity. At microscopic length scales smaller than the average network mesh size, the response is predominantly viscous. We use multiple particle tracking methods to measure the thermal fluctuations of 1 microm embedded tracer particles, and measure the viscosity to be approximately 20 mPa-s. We explore the impact of rheology on actin-dependent cytoplasmic contraction, and find that although microtubules modulate contractile forces in vitro, their interactions are not purely mechanical.
Andrä,
Targeted inactivation of plectin reveals essential function in maintaining the integrity of skin, muscle, and heart cytoarchitecture.
1997, Pubmed
Andrä,
Targeted inactivation of plectin reveals essential function in maintaining the integrity of skin, muscle, and heart cytoarchitecture.
1997,
Pubmed
Bausch,
Measurement of local viscoelasticity and forces in living cells by magnetic tweezers.
1999,
Pubmed
Benink,
Analysis of cortical flow models in vivo.
2000,
Pubmed
,
Xenbase
Boxer,
Interactions of actin, myosin, and an actin-binding protein of chronic myelogenous leukemia leukocytes.
1976,
Pubmed
Cameron,
Motility of ActA protein-coated microspheres driven by actin polymerization.
1999,
Pubmed
Canman,
Microtubules suppress actomyosin-based cortical flow in Xenopus oocytes.
1997,
Pubmed
,
Xenbase
Chen,
Rheological microscopy: local mechanical properties from microrheology.
2003,
Pubmed
Clark,
Actin in Xenopus oocytes.
1978,
Pubmed
,
Xenbase
Crocker,
Two-point microrheology of inhomogeneous soft materials.
2000,
Pubmed
Danowski,
Fibroblast contractility and actin organization are stimulated by microtubule inhibitors.
1989,
Pubmed
Desai,
The use of Xenopus egg extracts to study mitotic spindle assembly and function in vitro.
1999,
Pubmed
,
Xenbase
Fabry,
Scaling the microrheology of living cells.
2001,
Pubmed
Franz,
Cloning of cDNA and amino acid sequence of a cytokeratin expressed in oocytes of Xenopus laevis.
1986,
Pubmed
,
Xenbase
Franz,
Intermediate-size filaments in a germ cell: Expression of cytokeratins in oocytes and eggs of the frog Xenopus.
1983,
Pubmed
,
Xenbase
Gardel,
Microrheology of entangled F-actin solutions.
2003,
Pubmed
Herrmann,
Intermediate filaments and their associates: multi-talented structural elements specifying cytoarchitecture and cytodynamics.
2000,
Pubmed
Janmey,
Resemblance of actin-binding protein/actin gels to covalently crosslinked networks.
1990,
Pubmed
Janmey,
The cytoskeleton and cell signaling: component localization and mechanical coupling.
1998,
Pubmed
Janmey,
Effect of ATP on actin filament stiffness.
1990,
Pubmed
Janson,
Modulation of contraction by gelation/solation in a reconstituted motile model.
1991,
Pubmed
Jones,
Tracer diffusion through F-actin: effect of filament length and cross-linking.
1996,
Pubmed
Kane,
Actin polymerization and interaction with other proteins in temperature-induced gelation of sea urchin egg extracts.
1976,
Pubmed
Kane,
Induction of either contractile or structural actin-based gels in sea urchin egg cytoplasmic extract.
1980,
Pubmed
Kimelman,
The events of the midblastula transition in Xenopus are regulated by changes in the cell cycle.
1987,
Pubmed
,
Xenbase
Kolega,
The role of solation-contraction coupling in regulating stress fiber dynamics in nonmuscle cells.
1991,
Pubmed
Lau,
Microrheology, stress fluctuations, and active behavior of living cells.
2003,
Pubmed
Le Goff,
Motor-driven dynamics in actin-myosin networks.
2002,
Pubmed
Leno,
DNA replication in cell-free extracts from Xenopus laevis.
1991,
Pubmed
,
Xenbase
Levine,
One- and two-particle microrheology.
2000,
Pubmed
Luby-Phelps,
Probing the structure of cytoplasm.
1986,
Pubmed
Luby-Phelps,
Cytoarchitecture and physical properties of cytoplasm: volume, viscosity, diffusion, intracellular surface area.
2000,
Pubmed
Lyass,
Microtubule-dependent effect of phorbol ester on the contractility of cytoskeleton of cultured fibroblasts.
1988,
Pubmed
MacKintosh,
Elasticity of semiflexible biopolymer networks.
1995,
Pubmed
Mahaffy,
Scanning probe-based frequency-dependent microrheology of polymer gels and biological cells.
2000,
Pubmed
Mandato,
Xenopus egg extracts as a model system for analysis of microtubule, actin filament, and intermediate filament interactions.
2001,
Pubmed
,
Xenbase
Mason,
Optical measurements of frequency-dependent linear viscoelastic moduli of complex fluids.
1995,
Pubmed
Murray,
Cell cycle extracts.
1991,
Pubmed
Palazzo,
Microtubule-actin cross-talk at focal adhesions.
2002,
Pubmed
Palmer,
Diffusing wave spectroscopy microrheology of actin filament networks.
1999,
Pubmed
Rankin,
The surface contraction waves of Xenopus eggs reflect the metachronous cell-cycle state of the cytoplasm.
1997,
Pubmed
,
Xenbase
Rotsch,
Drug-induced changes of cytoskeletal structure and mechanics in fibroblasts: an atomic force microscopy study.
2000,
Pubmed
Ruddies,
The viscoelasticity of entangled actin networks: the influence of defects and modulation by talin and vinculin.
1993,
Pubmed
Shirasu,
Microtubule dynamics in Xenopus egg extracts.
1999,
Pubmed
,
Xenbase
Sider,
Direct observation of microtubule-f-actin interaction in cell free lysates.
1999,
Pubmed
,
Xenbase
Small,
How do microtubules guide migrating cells?
2002,
Pubmed
Taunton,
Actin-dependent propulsion of endosomes and lysosomes by recruitment of N-WASP.
2000,
Pubmed
,
Xenbase
Tempel,
Temperature-induced sol-gel transition and microgel formation in alpha -actinin cross-linked actin networks: A rheological study.
1996,
Pubmed
Theriot,
Involvement of profilin in the actin-based motility of L. monocytogenes in cells and in cell-free extracts.
1994,
Pubmed
,
Xenbase
Valentine,
Colloid surface chemistry critically affects multiple particle tracking measurements of biomaterials.
2004,
Pubmed
Wachsstock,
Cross-linker dynamics determine the mechanical properties of actin gels.
1994,
Pubmed
Waterman-Storer,
Microtubules remodel actomyosin networks in Xenopus egg extracts via two mechanisms of F-actin transport.
2000,
Pubmed
,
Xenbase
Weber,
F-actin serves as a template for cytokeratin organization in cell free extracts.
2002,
Pubmed
,
Xenbase
Xu,
Dynamic cross-linking by alpha-actinin determines the mechanical properties of actin filament networks.
1998,
Pubmed
