Micropatterned Structures for Studying the Mechanics of Biological Polymers

Schek, Henry T.; Hunt, Alan

doi:10.1007/s10544-005-6170-z

Cited by 18 publications

(14 citation statements)

References 14 publications

(14 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Interestingly, when in the simulation we exert a constant compressive force on the growing bundle, we observe length oscillations similar to chromosome oscillations measured in newt lung cells during pro-metaphase (19). polarity-aligned stabilized MTs, against a rigid microfabricated wall (17,20,21) (Fig. 1A).…”

supporting

confidence: 67%

Force-generation and dynamic instability of microtubule bundles

Laan

Husson

Munteanu

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

105

134

View full text Add to dashboard Cite

Individual dynamic microtubules can generate pushing or pulling forces when their growing or shrinking ends are in contact with cellular objects such as the cortex or chromosomes. These microtubules can operate in parallel bundles, for example when interacting with mitotic chromosomes. Here, we investigate the forcegenerating capabilities of a bundle of growing microtubules and study the effect that force has on the cooperative dynamics of such a bundle. We used an optical tweezers setup to study microtubule bundles growing against a microfabricated rigid barrier in vitro. We show that multiple microtubules can generate a pushing force that increases linearly with the number of microtubules present. In addition, the bundle can cooperatively switch to a shrinking state, due to a force-induced coupling of the dynamic instability of single microtubules. In the presence of GMPCPP, bundle catastrophes no longer occur, and high bundle forces are reached more effectively. We reproduce the observed behavior with a simple simulation of microtubule bundle dynamics that takes into account previously measured force effects on single microtubules. Using this simulation, we also show that a constant compressive force on a growing bundle leads to oscillations in bundle length that are of potential relevance for chromosome oscillations observed in living cells.chromosome oscillations ͉ optical tweezers ͉ simulations

show abstract

supporting

confidence: 67%

Force-generation and dynamic instability of microtubule bundles

Laan

Husson

Munteanu

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

105

134

View full text Add to dashboard Cite

show abstract

“…Force measurements were performed by using a keyhole trap (24) created with a Nd-YV04, 1,064-nm laser (Spectra Physics, Irvine, CA). Seven-micrometer-high barriers were made of SU-8 photo resist (MicroChem Corp., Newton, MA) on standard 25-mm-square glass coverslips (45). These coverslips were used in a flow cell as described in SI Text.…”

Section: Filament Counting and Elongation Rates By Electron Microscopymentioning

confidence: 99%

Direct measurement of force generation by actin filament polymerization using an optical trap

Footer

Kerssemakers

Theriot

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

340

358

View full text Add to dashboard Cite

Actin filament polymerization generates force for protrusion of the leading edge in motile cells. In protrusive structures, multiple actin filaments are arranged in cross-linked webs (as in lamellipodia or pseudopodia) or parallel bundles (as in filopodia). We have used an optical trap to directly measure the forces generated by elongation of a few parallel-growing actin filaments brought into apposition with a rigid barrier, mimicking the geometry of filopodial protrusion. We find that the growth of approximately eight actin parallel-growing filaments can be stalled by relatively small applied load forces on the order of 1 pN, consistent with the theoretical load required to stall the elongation of a single filament under our conditions. Indeed, large length fluctuations during the stall phase indicate that only the longest actin filament in the bundle is in contact with the barrier at any given time. These results suggest that force generation by small actin bundles is limited by a dynamic instability of single actin filaments, and therefore living cells must use actin-associated factors to suppress this instability to generate substantial forces by elongation of parallel bundles of actin filaments.acrosome ͉ stall force

show abstract

“…Wells with 7-m-high walls were made on a acidcleaned glass coverslip with photoresist ͑SU-8, MicroChem Corp., Newton, MA͒ by using standard microlithography techniques. 12 This way we could isolate a single bead in the 10 l distilled water sample kept at constant temperature ͑25°C͒ by a water-circulating system. A hydrodynamic drag force was applied on the bead by translating the sample mounted on a piezoelectric stage.…”

mentioning

confidence: 99%

Force spectroscopy of a single artificial biomolecule bond: The Kramers’ high-barrier limit holds close to the critical force

Husson

Dogterom

Pincet³

2009

The Journal of Chemical Physics

View full text Add to dashboard Cite

We use a minimal system with a single micron-size bead trapped with optical tweezers to investigate the kinetics of escape under force. Surprisingly, the exponential decay of the off rate with the barrier energy is still valid close to the critical force. Hence, the high viscosity approximation derived by Kramers in the case of a high energy barrier holds even for an energy barrier close to the thermal energy. Several recent models describe a single biomolecule bond by a smooth single-barrier energy profile. When this approach is accurate enough, our result justifies the use of Kramers’ approximation in the high-force regime, close to the critical force of the system, as done in recent single biomolecule bond studies.

show abstract

Micropatterned Structures for Studying the Mechanics of Biological Polymers

Cited by 18 publications

References 14 publications

Force-generation and dynamic instability of microtubule bundles

Force-generation and dynamic instability of microtubule bundles

Direct measurement of force generation by actin filament polymerization using an optical trap

Force spectroscopy of a single artificial biomolecule bond: The Kramers’ high-barrier limit holds close to the critical force

Contact Info

Product

Resources

About