Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

The Role of Actin and Myosin in Non-muscle Cells01:10

The Role of Actin and Myosin in Non-muscle Cells

4.0K
Actin and myosin or actomyosin filaments also play a significant role in cells other than those involved in muscle contraction (which occurs within the sarcomere of muscle cells). The mechanism of non-muscle cell contractile bundles was first observed in Dictyostelium and Acanthamoeba. In non-muscle cells, two bundles are commonly found: stress fibers and actomyosin adherence belts. These contractile bundles are smaller and less organized than the ones found in muscle cells. They  are held...
4.0K
Actin and Myosin in Muscle Contraction01:16

Actin and Myosin in Muscle Contraction

18.4K
Actin and myosin are contractile proteins that form the sarcomere found in skeletal muscle tissues for regulating muscle contraction. Actin, a globular contractile protein, interacts with myosin for muscle contraction. The skeletal tissue appears striped or striated under a microscope due to the repeated arrangement of contractile proteins actin and myosin along the length of myofibrils. Dark A bands and light I bands repeat along myofibrils, and the alignment of myofibrils in the cell causes...
18.4K
Actin Filament Depolymerization01:19

Actin Filament Depolymerization

3.5K
Actin filaments (F-actin) are composed of actin subunits. The dissociation of actin monomers can occur from either end of F-actin. The rate of dissociation is faster from the minus-end or the pointed end, where the actin subunits exist with a bound ADP, together known as ADP-actin. The depolymerization of F-actin is aided by proteins, including the actin-depolymerizing factor (ADF) and cofilin family of proteins, gelsolin, and glia maturation factor (GMF).
In F-actin, the ADF/cofilin proteins...
3.5K
Smooth Muscle Contraction01:25

Smooth Muscle Contraction

6.4K
Smooth muscle contraction is a complex process vital for various bodily functions, from maintaining blood vessel tension to facilitating the movement of food through the digestive tract. Unlike striated muscles, smooth muscle contraction begins more slowly and lasts longer.
The onset of contraction is triggered by an increase in calcium ions within the sarcoplasm, similar to the process in striated muscle. However, smooth muscles have a relatively smaller reservoir of the sarcoplasmic...
6.4K
Actin Polymerization and Cell Motility01:13

Actin Polymerization and Cell Motility

6.1K
Actin is a family of globular proteins that are highly abundant in eukaryotic cells. It makes up approximately 1-5% of total cell protein concentration. Actin monomers polymerize to form a complex network of polarized filaments, the actin cytoskeleton, that plays a crucial role in many cellular processes, including cell motility, division, endocytosis, and metastasis of cancer cells.
Actin cytoskeleton dynamics can produce pushing, pulling, and resistance forces that help the cell to migrate....
6.1K
Actin Treadmilling01:18

Actin Treadmilling

9.1K
Actin filaments undergo polymerization and depolymerization from either end. The polymerization and depolymerization rates depend on the cytosolic concentration of free G-actins. The polymerization rate is generally higher at the plus or barbed end, while the depolymerization rate is higher at the minus or pointed end. At a steady state, critical concentration describes the concentration of free G-actin monomers at which the polymerization rate at the plus end is equal to that of the...
9.1K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Enhancing subharmonic response by controlling initial state of monodisperse microbubbles via a multi-gas core.

Ultrasonics sonochemistry·2026
Same author

Type-specific antibody detection of herpes simplex virus types 1&2 (HSV-1&2) in fingerstick blood at point-of-care sites by a rapid and sensitive lateral flow immunochromatographic assay.

Journal of immunological methods·2026
Same author

Cordyceps sinensis polysaccharide disrupts the macrophage pyroptosis-neutrophil extracellular traps axis to ameliorate acute lung injury.

Journal of ethnopharmacology·2026
Same author

Traditional Chinese medicine for pediatric adenoid hypertrophy: an Umbrella review of methodological, reporting, and evidence quality.

Frontiers in allergy·2026
Same author

ROS-responsive tegafur-pheophorbide a conjugate-loaded microneedles for deep drug delivery and chemo-photodynamic therapy of superficial tumors.

International journal of pharmaceutics: X·2026
Same author

Immune Landscape and Tumour Heterogeneity in Ovarian Cancer: Insights From Single-Cell RNA Sequencing.

Journal of cellular and molecular medicine·2026

Related Experiment Video

Updated: Nov 28, 2025

The Mechanics of Poro-Elastic Contractile Actomyosin Networks As a Model System of the Cell Cytoskeleton
08:50

The Mechanics of Poro-Elastic Contractile Actomyosin Networks As a Model System of the Cell Cytoskeleton

Published on: March 10, 2023

1.0K

Motor-Free Contractility in Active Gels.

Sihan Chen1,2, Tomer Markovich2, Fred C MacKintosh1,2,3,4

  • 1Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA.

Physical Review Letters
|December 1, 2020
PubMed
Summary

This study introduces a novel motor-free mechanism for generating contraction in biopolymer networks. It utilizes active cross-linker dynamics and polymer properties to achieve contraction without molecular motors or substrate polarity.

More Related Videos

Tuning the Contractility and Deformation Modes of Active Actin-Based Assemblies In Vitro: From Two-Dimensional Active Networks to Liquid Crystal Drops
06:48

Tuning the Contractility and Deformation Modes of Active Actin-Based Assemblies In Vitro: From Two-Dimensional Active Networks to Liquid Crystal Drops

Published on: July 11, 2025

670
Myosin-Specific Adaptations of In vitro Fluorescence Microscopy-Based Motility Assays
08:57

Myosin-Specific Adaptations of In vitro Fluorescence Microscopy-Based Motility Assays

Published on: February 4, 2021

6.3K

Related Experiment Videos

Last Updated: Nov 28, 2025

The Mechanics of Poro-Elastic Contractile Actomyosin Networks As a Model System of the Cell Cytoskeleton
08:50

The Mechanics of Poro-Elastic Contractile Actomyosin Networks As a Model System of the Cell Cytoskeleton

Published on: March 10, 2023

1.0K
Tuning the Contractility and Deformation Modes of Active Actin-Based Assemblies In Vitro: From Two-Dimensional Active Networks to Liquid Crystal Drops
06:48

Tuning the Contractility and Deformation Modes of Active Actin-Based Assemblies In Vitro: From Two-Dimensional Active Networks to Liquid Crystal Drops

Published on: July 11, 2025

670
Myosin-Specific Adaptations of In vitro Fluorescence Microscopy-Based Motility Assays
08:57

Myosin-Specific Adaptations of In vitro Fluorescence Microscopy-Based Motility Assays

Published on: February 4, 2021

6.3K

Area of Science:

  • Biophysics
  • Cell Biology
  • Soft Matter Physics

Background:

  • Animal cells utilize contractile structures for motility and division.
  • Molecular motors like myosin typically drive these contractions, requiring polar substrates.
  • Existing models rely on motor-driven force generation.

Purpose of the Study:

  • To propose and investigate a motor-free mechanism for generating contraction in biopolymer networks.
  • To demonstrate contraction without the need for molecular motors or substrate polarity.
  • To elucidate the underlying biophysical principles of this novel contraction mechanism.

Main Methods:

  • Theoretical modeling of biopolymer networks.
  • Incorporation of active binding and unbinding dynamics of cross-linkers.
  • Analysis of asymmetric force-extension relationships in semiflexible polymers.
  • Development of coarse-grained and microscopic models.

Main Results:

  • A motor-free mechanism capable of generating steady-state contraction in biopolymer networks was identified.
  • The mechanism relies on active cross-linker dynamics and the asymmetric response of polymers.
  • Contraction occurs via a nonthermal, ratchet-like process, independent of molecular motors.
  • Force-velocity relationships were calculated using both coarse-grained and microscopic models.

Conclusions:

  • Active cross-linker dynamics breaking detailed balance, combined with polymer asymmetry, can drive network contraction.
  • This provides a fundamental, motor-independent mechanism for force generation in biological and synthetic networks.
  • The findings offer new perspectives on cellular mechanics and the design of active soft materials.