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

Overview of Myosin Structure and Function

Overview of Myosin Structure and Function

Myosins are a family of molecular motor proteins, first identified in the skeletal muscles, where they are responsible for muscle contraction. Along with their role in muscle contraction, these proteins also play a role in the intracellular transport of molecules and vesicles. There are twenty-four classes of myosins based on their domain sequence and organization. Of the twenty-four, six classes (Myosin I, Myosin II, Myosin V, Myosin VI, Myosin VII, and Myosin X) have been well characterized.

Role of Myosin in Cell Migration

Role of Myosin in Cell Migration

Myosins are multimeric motor proteins involved in various cellular processes such as migration, adhesion, and proliferation. Myosin II is the most common type in animal cells, which binds and cross-links actin filaments.
Myosin II is a hexamer comprising two heavy chains with globular heads and coiled-coil tails, two regulatory light chains, and two essential light chains. The ATPase sites on the myosin heads hydrolyze ATP, and the released phosphate generates the force for contraction. It is...

Actin and Myosin in Muscle Contraction

Actin and Myosin in Muscle Contraction

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...

Mechanical Protein Functions

Mechanical Protein Functions

Proteins perform many mechanical functions in a cell. These proteins can be classified into two general categories- proteins that generate mechanical forces and proteins that are subjected to mechanical forces. Proteins providing mechanical support to the structure of the cell, such as keratin, are subjected to mechanical force, whereas proteins involved in cell movement and transport of molecules across cell membranes, such as an ion pump, are examples of generating mechanical force.

The Role of Actin and Myosin in Non-muscle Cells

The Role of Actin and Myosin in Non-muscle Cells

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...

The Sarcomere

The Sarcomere

A sarcomere is a microscopic segment repeating in a myofibril. The sarcomere fundamentally consists of two main myofilaments: thick filaments called myosin and thin filaments called actin. These filaments interact by sliding past each other in response to stimulus. In addition to myosin and actin, several other proteins, such as tropomyosin, troponin, titin, nebulin, myomesin, α-actinin, and dystrophin, play crucial roles in regulating, structuring, and functioning of the sarcomere.
Each myosin...

You might also read

Related Articles

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

Sort by

Same author

Modeling time to visual insight in Mooney image recognition with a chaotic recurrent neural network.

Cognitive neurodynamics·2026

Same author

Impact of Different Attitudes toward Face-to-Face and Online Classes on Learning Outcomes in Japan.

Pharmacy (Basel, Switzerland)·2023

Same author

Singing Experience Influences RSST Scores.

Healthcare (Basel, Switzerland)·2022

Same author

Functional cortical localization of tongue movements using corticokinematic coherence with a deep learning-assisted motion capture system.

Scientific reports·2022

Same author

The Synergic Role of Actomyosin Architecture and Biased Detachment in Muscle Energetics: Insights in Cross Bridge Mechanism Beyond the Lever-Arm Swing.

International journal of molecular sciences·2021

Same author

Activation probability of a single naïve T cell upon TCR ligation is controlled by T cells interacting with the same antigen-presenting cell.

FEBS letters·2021

Search research articles

Related Experiment Video

Updated: Jul 18, 2026

Probing Myosin Ensemble Mechanics in Actin Filament Bundles Using Optical Tweezers

Probing Myosin Ensemble Mechanics in Actin Filament Bundles Using Optical Tweezers

Published on: May 4, 2022

Cooperative actions between myosin heads bring effective functions.

Seiji Esaki¹, Yoshiharu Ishii, Masatoshi Nishikawa

¹Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan. esaki@phys1.med.osaka-u.ac.jp

|December 26, 2006

Summary

Muscle myosin motors generate multiple steps per ATP molecule, but individual heads move less than a half actin filament pitch. Cooperative action in muscles allows greater movement, loosely coupled to ATP hydrolysis.

More Related Videos

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

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

Published on: February 4, 2021

Related Experiment Videos

Last Updated: Jul 18, 2026

Probing Myosin Ensemble Mechanics in Actin Filament Bundles Using Optical Tweezers

Probing Myosin Ensemble Mechanics in Actin Filament Bundles Using Optical Tweezers

Published on: May 4, 2022

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

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

Published on: February 4, 2021

Area of Science:

Biophysics
Molecular Biology
Muscle Physiology

Background:

Single molecule studies show muscle myosin (a molecular motor) takes multiple steps along actin filaments per ATP hydrolysis.
Previous models demonstrated thermal fluctuation is key to myosin's stochastic movement.
Individual myosin heads move less than a half actin filament pitch, contrasting with muscle observations of >60 nm displacement.

Purpose of the Study:

To investigate the cooperative action between myosin heads in muscle.
To extend a model of isolated myosin heads to a system simulating muscle arrangement.
To understand how cooperativity enables larger displacements than observed for single heads.

Main Methods:

Developed a computational model of aligned myosin heads in a muscle arrangement.
Incorporated ATPase reaction cycles and interactions between myosin heads.
Simulated actin filament rotation, ATP binding, and ATPase product release.

Main Results:

The model demonstrated that cooperative action allows myosin filaments to move greater than a half actin filament pitch per ATP hydrolysis.
Actin filament rotation and interactions between myosin heads contribute to enhanced movement.
The simulated movement was loosely coupled to the ATPase cycle, mirroring muscle observations.

Conclusions:

Cooperative interactions among myosin heads are crucial for efficient muscle contraction.
The model successfully reproduces the large displacements observed in muscle, suggesting a mechanism for coordinated motor function.
Muscle myosin's movement is not tightly coupled to ATP hydrolysis, allowing for flexibility and efficiency in contraction.