Alexander Verkhovskiy

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Traction forces are generated by cellular actin-myosin system and transmitted to the environment through adhesions. They are believed to drive cell motion, shape changes, and extracellular matrix remodeling [1 -3] . However, most of the traction force anal ...

The mechanical interaction between adherent cells and their substrate relies on the formation of adhesion sites and on the stabilization of contractile acto-myosin bundles, or stress fibers. The shape of the cell and the orientation of these fibers can be ...

Accurate extraction of cell outlines from microscopy images is essential for analysing the dynamics of migrating cells. Phase-contrast microscopy is one of the most common and convenient imaging modalities for observing cell motility because it does not re ...

Dynamic actin network at the leading edge of the cell is linked to the extracellular matrix through focal adhesions (FAs), and at the same time it undergoes retrograde flow with different dynamics in two distinct zones: the lamellipodium (peripheral zone o ...

Protrusion, the first step of cell migration, is driven by actin polymerization coupled to adhesion at the cell's leading edge. Polymerization and adhesive forces have been estimated, but the net protrusion force has not been measured accurately. We arrest ...

We propose a new technique to measure the volume of adherent migrating cells. The method is based on a negative staining where a fluorescent, non-cell-permeant dye is added to the extracellular medium. The specimen is observed with a conventional fluoresce ...

To understand the mechanism of cell migration, one needs to know how the parts of the motile machinery of the cell are assembled and how they move with respect to each other. Actin and myosin II are thought to be the major structural and force-generating c ...

Actin-myosin filament bundles (stress fibers) are critical for tension generation and cell shape, but their mechanical properties are difficult to access. Here we propose a novel approach to probe individual peripheral stress fibers in living cells through ...

Plasma membrane tension and the pressure generated by actin polymerization are two antagonistic forces believed to define the protrusion rate at the leading edge of migrating cells [1-5]. Quantitatively, resistance to actin protrusion is a product of membr ...

Protrusion of lamellipodia during cell migration depends on the assembly of actin network. The assembly mechanism, based on dendritic filament branching, has been investigated in reconstituted in vitro systems, but little is known about the dynamical and s ...

During cell migration, forces generated by the actin cytoskeleton are transmitted through adhesion complexes to the substrate. To investigate the mechanism of force generation and transmission, we analyzed the relationship between actin network velocity an ...

The lamellipod, the locomotory region of migratory cells, is shaped by the balance of protrusion and contraction. The latter is the result of myosin-generated centripetal flow of the viscoelastic actin network. Recently, quantitative flow data was obtained, yet there is no detailed theory explaining the flow in a realistic geometry. We introduce models of viscoelastic actin mechanics and myosin transport and solve the model equations numerically for the flat, fan-shaped lamellipodial domain of keratocytes.

Actin-myosin microfilament bundles or stress-fibers are the principal tension-generating structures in the cell. Their mechanical properties are critical for cell shape, motion, and interaction with other cells and extracellular matrix, but were so far dif ...

How cells break symmetry and organize activity at their edges to move directionally is a fundamental question in cell biology. Physical models of cell motility commonly incorporate gradients of regulatory proteins and/or feedback from the motion itself to ...

Leading edge protrusion is one of the critical events in the cell motility cycle and it is believed to be driven by the assembly of the actin network. The concept of dendritic nucleation of actin filaments provides a basis for understanding the organization and dynamics of the actin network at the molecular level. At a larger scale, the dynamic geometry of the cell edge has been described in terms of the graded radial extension model, but this level of description has not yet been linked to the molecular dy

Anterior-posterior polarity in the Caenorhabditis elegans zygote depends on two groups of PAR proteins, as well as on cortical flow. Recent work now demonstrates that this polarization results from a transition in a bistable reaction-diffusion system of PA ...

When force is applied to cell-matrix adhesion complexes, they respond by growing larger and stronger. It emerges that strengthening involves transient motion of the transmembrane integrin receptors and their eventual immobilization to the extracellular mat ...

Actin assembly at the leading edge of the cell is believed to drive protrusion, whereas membrane resistance and contractile forces result in retrograde flow of the assembled actin network away from the edge. Thus, cell motion and shape changes are expected ...

Actin network in the front part of a moving cell is organized into a lamellipodium and a lamellum. A distinct lamellipodium-lamellum interface is associated with focal adhesions and consists of a series of arclike segments linking neighboring focal adhesio ...

Changes in mechanical properties of the cytoplasm have been implicated in cell motility, but there is little information about these properties in specific regions of the cell at specific stages of the cell migration process. Fish epidermal keratocytes wit ...

Alexander Verkhovskiy

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Traction Forces Control Cell-Edge Dynamics and Mediate Distance Sensitivity during Cell Polarization

Cell Shape Dynamics Reveal Balance of Elasticity and Contractility in Peripheral Arcs

High-resolution cell outline segmentation and tracking from phase-contrast microscopy images

Comparative dynamics of retrograde actin flow and focal adhesions: formation of nascent adhesions triggers transition from fast to slow flow

Weak force stalls protrusion at the leading edge of the lamellipodium

Dynamic measurement of the height and volume of migrating cells by a novel fluorescence microscopy technique

Comparative maps of motion and assembly of filamentous actin and myosin II in migrating cells

Microsurgery-aided in-situ force probing reveals extensibility and viscoelastic properties of individual stress fibers

Contact Angle at the Leading Edge Controls Cell Protrusion Rate

Analysis of actin filament network organization in lamellipodia by comparing experimental and simulated images

Force transmission in migrating cells

Actin-myosin viscoelastic flow in the keratocyte lamellipod

Ultra-soft cantilevers and 3-D micro-patterned substrates for contractile bundle tension measurement in living cells

Minimal model for spontaneous cell polarization and edge activity in oscillating, rotating and migrating cells

Analysis of actin dynamics at the leading edge of crawling cells: implications for the shape of keratocyte lamellipodia

Cell Polarization: Mechanical Switch for a Chemical Reaction

Cell-Matrix Adhesion: Slip and Immobilization under Force

Tracking retrograde flow in keratocytes: news from the front

Role of focal adhesions and mechanical stresses in the formation and progression of the lamellum interface

Gradient of Rigidity in the Lamellipodia of Migrating Cells Revealed by Atomic Force Microscopy