Related Experiment Video

Updated: Jun 20, 2025

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

5.9K

Functional control of myosin motors in the cardiac cycle

Malcolm Irving1

  • 1Randall Centre for Cell and Molecular Biophysics and BHF Centre for Research Excellence, King's College London, London, UK. malcolm.irving@kcl.ac.uk.

Nature Reviews. Cardiology
|July 19, 2024
PubMed

Insights

Heart muscle contraction relies on myosin and actin interactions. Efficient heart function depends on regulating active myosin motors, a process often disrupted in inherited heart disease.

Area of Science:

  • Cardiovascular Physiology
  • Muscle Contraction Biology
  • Biophysics of Cardiac Muscle

Background:

  • Cardiac contraction is driven by myosin-actin interactions fueled by ATP hydrolysis.
  • Heart muscle structure and synchronized beating ensure coupling between molecular and organ-level cycles.
  • Myosin motors drive pressure changes, controlling heart valve function and contraction modes.

Purpose of the Study:

  • To elucidate the relationship between myosin motor activity and cardiac cycle dynamics.
  • To investigate the regulation of myosin motor engagement in heart contraction.
  • To explore the implications of myosin motor regulation for inherited heart disease therapies.

Main Methods:

  • Analysis of myosin ATPase cycle and cardiac cycle coupling.
  • Computational modeling to estimate myosin motor involvement in pressure generation.
  • Review of existing literature on myosin motor function in cardiac muscle.

Main Results:

  • Peak filament stress in the heart is significantly lower than in skeletal muscle.
  • Approximately 5% of cardiac myosin motors generate peak systolic pressure; more are needed for ejection.
  • Regulation of active myosin motor number is critical for healthy heart function.

Conclusions:

  • Tight regulation of myosin motor activity is essential for efficient cardiac function.
  • Disruption of this regulation by gene variants is linked to inherited heart disease.
  • Restoring myosin motor control may offer a therapeutic target for heart disease.

More Related Videos

Probing Myosin Ensemble Mechanics in Actin Filament Bundles Using Optical Tweezers06:53

Probing Myosin Ensemble Mechanics in Actin Filament Bundles Using Optical Tweezers

Published on: May 4, 2022

2.2K
Mechanical Control of Relaxation Using Intact Cardiac Trabeculae07:51

Mechanical Control of Relaxation Using Intact Cardiac Trabeculae

Published on: February 17, 2023

1.2K

Related Concept Videos

Specialized Characteristics of Cardiac Muscles01:27

Specialized Characteristics of Cardiac Muscles

The primary role of cardiac muscles is to propel blood throughout the cardiovascular system. The cardiac muscle cells, or cardiomyocytes, exhibit specialized characteristics that allow them to perform this function.
Cardiac muscle cells are smaller than skeletal muscles, averaging 10–20 mm in diameter and 50–100 mm in length. However, they have large energy demands for continuous contraction and relaxation. This energy is almost exclusively derived from aerobic metabolism of energy...
2.4K
Actin and Myosin in Muscle Contraction01:16

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...
9.8K
Overview of Myosin Structure and Function01:15

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...
4.1K
Cross-bridge Cycle01:26

Cross-bridge Cycle

As muscle contracts, the overlap between the thin and thick filaments increases, decreasing the length of the sarcomere—the contractile unit of the muscle—using energy in the form of ATP. At the molecular level, this is a cyclic, multistep process that involves binding and hydrolysis of ATP, and movement of actin by myosin.
117.2K
Smooth Muscle Contraction01:25

Smooth Muscle Contraction

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...
2.7K
Pathophysiology of Cardiac Performance01:29

Pathophysiology of Cardiac Performance

Typical heart performance is influenced by heart rate, rhythm, myocardial contraction, and metabolism or blood flow. The cardiac muscle exhibits distinct electrophysiological features, including pacemaker activity and calcium channel control, which play a vital role in the heart's response to various drugs. The autonomic nervous system, comprising the sympathetic and parasympathetic branches, regulates heart rate. Sympathetic activation increases heart rate, while parasympathetic activation...
625