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

Structure of Cardiac Muscles

Structure of Cardiac Muscles

Cardiac muscle, or myocardium, is a specialized type of muscle found exclusively in the heart. Its unique structural and functional characteristics enable the heart to perform its vital role of pumping blood throughout the body continuously and rhythmically. The cardiac muscle cells, or cardiomyocytes, possess an endomysium and perimysium but do not have an epimysium.
Compared to skeletal muscles, cardiac muscle cells are small and mostly have a single nucleus. Additionally, they are usually...

You might also read

Related Articles

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

Sort by

Same author

Evaluating Pathogenicity of <i>TPM1</i> Variants of Unknown Significance Using In-silico and In-vitro Models.

Journal of precision medicine (Amsterdam, Netherlands)·2026

Same author

The Structural Role of Tropomyosin in Regulating Thin Filament Activation of Actin-Myosin Interaction.

Sub-cellular biochemistry·2026

Same author

Pseudo-acetylation of ACTC1 K326 and K328 promotes dysinhibition of reconstituted human cardiac thin filaments.

Journal of molecular and cellular cardiology·2025

Same author

Screening single nucleotide changes to tropomyosin to identify novel cardiomyopathy mutants.

Journal of molecular and cellular cardiology·2025

Same author

Velcro-binding by cardiac troponin-I traps tropomyosin on actin in a low-energy relaxed state.

Biochemical and biophysical research communications·2025

Same author

Dual role of Tropomyosin-R160 in thin filament regulation: Insights into phosphorylation-dependent cardiac relaxation and cardiomyopathy mechanisms.

Archives of biochemistry and biophysics·2025

Search research articles

Related Experiment Video

Updated: Sep 5, 2025

Creating a Structurally Realistic Finite Element Geometric Model of a Cardiomyocyte to Study the Role of Cellular Architecture in Cardiomyocyte Systems Biology

Creating a Structurally Realistic Finite Element Geometric Model of a Cardiomyocyte to Study the Role of Cellular Architecture in Cardiomyocyte Systems Biology

Published on: April 18, 2018

Modeling Human Cardiac Thin Filament Structures.

Michael J Rynkiewicz¹, Elumalai Pavadai¹, William Lehman¹

¹Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA, United States.

Frontiers in Physiology

|July 11, 2022

Summary

Muscle contraction relies on calcium-dependent tropomyosin/troponin movements. This study refines thin filament models, improving understanding of interactions crucial for muscle function and disease.

Keywords:

actin cryoEM protein-protein docking tropomyosin troponin

More Related Videos

3D Human Myocardial Tissue Generation Using Melt Electrospinning Writing of Polycaprolactone Scaffolds and hiPSC-Derived Cardiac Cells

3D Human Myocardial Tissue Generation Using Melt Electrospinning Writing of Polycaprolactone Scaffolds and hiPSC-Derived Cardiac Cells

Published on: March 28, 2025

Patient-specific Modeling of the Heart: Estimation of Ventricular Fiber Orientations

Patient-specific Modeling of the Heart: Estimation of Ventricular Fiber Orientations

Published on: January 8, 2013

Related Experiment Videos

Last Updated: Sep 5, 2025

Creating a Structurally Realistic Finite Element Geometric Model of a Cardiomyocyte to Study the Role of Cellular Architecture in Cardiomyocyte Systems Biology

Creating a Structurally Realistic Finite Element Geometric Model of a Cardiomyocyte to Study the Role of Cellular Architecture in Cardiomyocyte Systems Biology

Published on: April 18, 2018

3D Human Myocardial Tissue Generation Using Melt Electrospinning Writing of Polycaprolactone Scaffolds and hiPSC-Derived Cardiac Cells

3D Human Myocardial Tissue Generation Using Melt Electrospinning Writing of Polycaprolactone Scaffolds and hiPSC-Derived Cardiac Cells

Published on: March 28, 2025

Patient-specific Modeling of the Heart: Estimation of Ventricular Fiber Orientations

Patient-specific Modeling of the Heart: Estimation of Ventricular Fiber Orientations

Published on: January 8, 2013

Area of Science:

Biophysics
Structural Biology
Muscle Physiology

Background:

Striated muscle contraction is regulated by calcium-dependent movements of the tropomyosin/troponin complex on actin filaments.
Understanding these dynamics is key to addressing mutation-induced muscle disorders like cardiomyopathies and myopathies.

Purpose of the Study:

To improve atomic-level models of the muscle thin filament.
To refine understanding of tropomyosin-troponin interactions in calcium-dependent regulation.
To provide insights into the structural basis of muscle contractile dysfunction.

Main Methods:

Utilized cryoelectron microscopy (cryoEM) data for structural analysis.
Employed computational techniques including de novo structure prediction, protein-protein docking, and molecular dynamics simulations.
Refined existing cryoEM models to correct helical parameters and improve density matching.

Main Results:

Developed improved models of the troponin T domain and its interaction with tropomyosin.
Corrected inaccuracies in previously published cryoEM models, particularly regarding alpha-helix structures.
Reinterpreted tropomyosin-troponin I interactions, identifying key features maintaining the low-calcium, blocked state.

Conclusions:

Revised thin filament models offer enhanced accuracy in intermolecular interactions for both low- and high-calcium states.
These refined models provide novel insights into the molecular mechanisms of muscle contraction regulation.
Improved structural models are essential for understanding and potentially treating muscle-related diseases.