Related Experiment Video

Updated: May 19, 2026

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

Molecular mechanics of cardiac myosin-binding protein C in native thick filaments

M J Previs1, S Beck Previs, J Gulick

  • 1Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT 05405, USA.

Science (New York, N.Y.)
|August 28, 2012
PubMed

Insights

Cardiac myosin-binding protein C (cMyBP-C) regulates heart muscle contraction by slowing actomyosin interactions. This finding offers molecular insights into hypertrophic cardiomyopathy and cardiac contractility.

Area of Science:

  • Cardiovascular Biology
  • Muscle Physiology
  • Molecular Motors

Background:

  • Heart pumping relies on actomyosin molecular motors.
  • Mutations in cardiac myosin-binding protein C (cMyBP-C) are linked to hypertrophic cardiomyopathy.
  • The precise role of cMyBP-C in regulating cardiac contractility remains unclear.

Purpose of the Study:

  • To investigate the molecular mechanisms by which cMyBP-C modulates cardiac contractility.
  • To determine the functional impact of cMyBP-C on actomyosin motor activity in native cardiac thick filaments.

Main Methods:

  • Single-particle fluorescence imaging
  • Transgenic protein expression
  • Proteomics
  • Computational modeling

Main Results:

  • cMyBP-C was found to slow actomyosin motion generation within the C-zones of cardiac thick filaments.
  • This mechanical regulation by cMyBP-C is influenced by phosphorylation and proteolytic degradation.
  • The study identified cMyBP-C as a key modulator of cardiac muscle contraction.

Conclusions:

  • cMyBP-C acts as a regulator of actomyosin motor function in the heart.
  • Understanding cMyBP-C's role provides insights into hypertrophic cardiomyopathy.
  • cMyBP-C is integral to a tripartite complex with actin and myosin for fine-tuning cardiac contraction.

More Related Videos

Myosin-Specific Adaptations of In vitro Fluorescence Microscopy-Based Motility Assays08:57

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

Published on: February 4, 2021

Related Concept Videos

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...
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 characterized.
Studying the Cytoskeleton01:17

Studying the Cytoskeleton

The cytoskeletal architecture can be studied using different microscopic and biochemical techniques. Electron microscopy was instrumental in discovering the cytoskeletal architecture around the 1960s, which allowed obtaining structural information at a high-resolution level. However, the sample preparation procedure often limits this ability in biological samples. Several protocols have been developed over the years to optimize sample preparation. In one of the protocols known as rotary...
The Sarcomere01:08

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...
The Role of Actin and Myosin in Non-muscle Cells01:10

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...
Mechanical Protein Functions01:58

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.