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

Generation of Straight or Branched Actin Filaments01:14

Generation of Straight or Branched Actin Filaments

3.9K
The straight or branched structure formation of actin filaments is controlled by nucleating proteins such as the formins and Arp2/3 complex. Formin-mediated assembly results in straight filaments, whereas Arp2/3 protein complex-mediated assembly results in branched actin filaments.
Arp2/3 Complex
Arp2/3 complex is a seven-subunit complex consisting of two proteins similar to actin- Arp2 and Arp3, and five other subunits that help keep Arp2 and Arp3 inactive. When required, the complex is...
3.9K
Actin Filament Depolymerization01:19

Actin Filament Depolymerization

4.0K
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...
4.0K
Formation of Higher-order Actin Filaments01:11

Formation of Higher-order Actin Filaments

3.7K
The polymerization of G-actin monomers into filamentous F-actin is a multi-step process. Once the F-actins are formed, they can bundle together in different arrangements to form higher-order networks and regulate cellular functions. Common examples include the formation of lamellipodia and filopodia at the cell's leading edge by actin reorganization in a migrating cell. The microvilli on the brush border epithelial cells are also formed through the F-actin network.
The high-order actin...
3.7K
The Role of Actin and Myosin in Non-muscle Cells01:10

The Role of Actin and Myosin in Non-muscle Cells

5.1K
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...
5.1K
Introduction to Actin01:26

Introduction to Actin

6.7K
Actin is a highly conserved cytoskeletal protein found abundantly in eukaryotic cells. It constitutes 10% weight of the total cellular protein in muscle cells, while in non-muscle cells, it is lower and makes up around 1–5 percent of the total cell protein. Actin found in the unicellular amoebae and complex multicellular animals is around 80% similar, demonstrating their conservation over a billion years of evolution.  Actin coding genes are conserved within species and across...
6.7K
Actin Polymerization01:42

Actin Polymerization

8.7K
Actin polymerization occurs through the head-to-tail association of binding sites on monomeric actin or G-actin to form filamentous or F-actin. The polymerization can be divided into three phases ̶  nucleation, elongation, and steady-state phase.
The nucleation phase involves forming a stable nucleus consisting of three actin monomers to form a new actin filament. Actin-binding proteins such as formins and Arp2/3 complex help filament growth post-nucleation. The Formins form straight...
8.7K

You might also read

Related Articles

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

Sort by
Same author

Modeling tumor transport and growth with poroelastic biopolymer networks.

Soft matter·2026
Same author

Spatiotemporal mapping of microscale stiffness during collagen polymerization and crosslinking by optical multifrequency time-harmonic elastography.

Soft matter·2026
Same author

Modeling tumor transport and growth with poroelastic biopolymer networks.

bioRxiv : the preprint server for biology·2025
Same author

Birth mode is associated with layer-specific mechanical changes in fetal membranes.

Scientific reports·2025
Same author

Two-year outcomes of epicranial focal cortex stimulation in pharmacoresistant focal epilepsy.

Epilepsia·2025
Same author

Poroelasticity and permeability of fibrous polymer networks under compression.

Soft matter·2025

Related Experiment Video

Updated: Feb 20, 2026

Using Microfluidics and Fluorescence Microscopy to Study the Assembly Dynamics of Single Actin Filaments and Bundles
08:02

Using Microfluidics and Fluorescence Microscopy to Study the Assembly Dynamics of Single Actin Filaments and Bundles

Published on: May 5, 2022

3.2K

Single Actin Bundle Rheology.

Dan Strehle1, Paul Mollenkopf2,3, Martin Glaser4,5

  • 1Faculty of Physics and Earth Sciences, Peter Debye Institute, Leipzig University, Linnéstr. 5, 04103 Leipzig, Germany. dan.strehle@gmx.net.

Molecules (Basel, Switzerland)
|October 25, 2017
PubMed
Summary

Researchers developed a new method to measure the bending stiffness of actin bundles. Thin bundles act like semiflexible polymers, while thicker bundles exhibit frequency-dependent stiffness not predicted by current models.

Keywords:
actinbiopolymersbundlesdynamicsmechanical propertiesoptical tweezersrheology

More Related Videos

Probing Myosin Ensemble Mechanics in Actin Filament Bundles Using Optical Tweezers
06:53

Probing Myosin Ensemble Mechanics in Actin Filament Bundles Using Optical Tweezers

Published on: May 4, 2022

2.7K
Reconstituting and Characterizing Actin-Microtubule Composites with Tunable Motor-Driven Dynamics and Mechanics
09:10

Reconstituting and Characterizing Actin-Microtubule Composites with Tunable Motor-Driven Dynamics and Mechanics

Published on: August 25, 2022

3.9K

Related Experiment Videos

Last Updated: Feb 20, 2026

Using Microfluidics and Fluorescence Microscopy to Study the Assembly Dynamics of Single Actin Filaments and Bundles
08:02

Using Microfluidics and Fluorescence Microscopy to Study the Assembly Dynamics of Single Actin Filaments and Bundles

Published on: May 5, 2022

3.2K
Probing Myosin Ensemble Mechanics in Actin Filament Bundles Using Optical Tweezers
06:53

Probing Myosin Ensemble Mechanics in Actin Filament Bundles Using Optical Tweezers

Published on: May 4, 2022

2.7K
Reconstituting and Characterizing Actin-Microtubule Composites with Tunable Motor-Driven Dynamics and Mechanics
09:10

Reconstituting and Characterizing Actin-Microtubule Composites with Tunable Motor-Driven Dynamics and Mechanics

Published on: August 25, 2022

3.9K

Area of Science:

  • Cell biology
  • Biophysics
  • Materials science

Background:

  • Bundled actin structures are crucial for cell mechanics but are understudied compared to single filaments.
  • Previous methods for determining bundle mechanical properties relied on passive observation of thermal fluctuations.
  • Anisotropic bundled structures present unique challenges for mechanical characterization.

Purpose of the Study:

  • To develop and apply a novel method for measuring the bending stiffness of individual actin bundles.
  • To investigate the mechanical behavior of actin bundles with varying thickness and filament composition.
  • To compare experimental results with theoretical models like the wormlike chain model.

Main Methods:

  • Active oscillation induction and decay measurement to determine bending stiffness.
  • Systematic testing of anisotropic bundled actin structures.
  • Comparison of thin (depletion force-induced) and thick (merged) bundles.

Main Results:

  • Thin actin bundles behave as semiflexible polymers, consistent with wormlike chain model predictions.
  • Thicker actin bundles exhibit frequency-dependent bending stiffness.
  • This frequency-dependent behavior deviates from standard wormlike chain model predictions.

Conclusions:

  • The new method allows for systematic characterization of anisotropic actin bundle mechanics.
  • Thicker bundles display complex mechanical properties, suggesting internal processes not captured by simple polymer models.
  • Further theoretical development, such as wormlike bundle theory, may be needed to explain the behavior of thicker bundles.