Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Generation of Straight or Branched Actin Filaments

Generation of Straight or Branched Actin Filaments

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...

Introduction to Actin

Introduction to Actin

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 different species.

Formation of Higher-order Actin Filaments

Formation of Higher-order Actin Filaments

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 networks...

Actin Polymerization

Actin Polymerization

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 actin...

Actin Polymerization and Cell Motility

Actin Polymerization and Cell Motility

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.

Actin Filament Depolymerization

Actin Filament Depolymerization

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...

You might also read

Related Articles

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

Sort by

Same author

The molecular architecture of tunneling nanotubes.

bioRxiv : the preprint server for biology·2026

Same author

Force-modulated structural landscape of the catch bonding F-actin crosslinker α-actinin-4.

bioRxiv : the preprint server for biology·2026

Same author

Synthetic nanomachine reveals mechanics of a non-muscle actinopathy mutation in γ-actin.

The Journal of physiology·2026

Same author

Cytoskeleton Spotlight: Alfred C. Chin.

Cytoskeleton (Hoboken, N.J.)·2025

Same author

Cryo-EM captures early intermediate steps in dynein activation by LIS1.

Nature communications·2025

Same author

Multiple steps of dynein activation by Lis1 visualized by cryo-EM.

Nature structural & molecular biology·2025

Search research articles

Related Experiment Video

Updated: May 19, 2026

Measuring Protein Binding to F-actin by Co-sedimentation

Measuring Protein Binding to F-actin by Co-sedimentation

Published on: May 18, 2017

Foundational Discoveries in Actin Regulation: An Interview With Tom Pollard.

Alfred C Chin¹, Eva P Karasmanis^2,3

¹Weill Cornell/Rockefeller/Sloan Kettering Tri-Institutional MD-PhD Program, New York, New York, USA.

Cytoskeleton (Hoboken, N.J.)

|May 18, 2026

Summary

Dr. Pollard pioneered quantitative cell biology, defining actin dynamics and cellular motility principles. His work integrated diverse methods, establishing the mechanistic basis of cytoskeleton organization and function.

More Related Videos

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

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

Published on: May 5, 2022

Aip1p Dynamics Are Altered by the R256H Mutation in Actin

Aip1p Dynamics Are Altered by the R256H Mutation in Actin

Published on: July 30, 2014

Related Experiment Videos

Last Updated: May 19, 2026

Measuring Protein Binding to F-actin by Co-sedimentation

Measuring Protein Binding to F-actin by Co-sedimentation

Published on: May 18, 2017

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

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

Published on: May 5, 2022

Aip1p Dynamics Are Altered by the R256H Mutation in Actin

Aip1p Dynamics Are Altered by the R256H Mutation in Actin

Published on: July 30, 2014

Area of Science:

Cell Biology
Biochemistry
Biophysics

Background:

Cytoskeleton research historically lacked quantitative and mechanistic approaches.
Actin dynamics were poorly understood at a molecular level.

Purpose of the Study:

To review Dr. Thomas D. Pollard's transformative contributions to cytoskeleton research.
To highlight the integration of quantitative methods in understanding actin dynamics and cellular motility.

Main Methods:

Biochemistry and structural biology to elucidate molecular mechanisms.
Genetics and advanced microscopy for in vivo visualization.
Mathematical modeling to define kinetic and dynamic principles.

Main Results:

Established core principles of actin filament polarity and assembly kinetics.
Defined the role of unconventional myosins in cellular processes.
Elucidated the molecular basis of branched actin networks and contractile ring formation.

Conclusions:

Dr. Pollard's work established a quantitative, mechanistic framework for cytoskeleton research.
His interdisciplinary approach fostered a new generation of cell biologists.
Quantitative thinking is crucial for advancing our understanding of cellular architecture and motility.