Related Experiment Video

Updated: Jul 9, 2026

Cardiac Muscle Cell-based Actuator and Self-stabilizing Biorobot - Part 2
09:33

Cardiac Muscle Cell-based Actuator and Self-stabilizing Biorobot - Part 2

Published on: May 9, 2017

Myosin VI is an actin-based motor that moves backwards

A L Wells1, A W Lin, L Q Chen

  • 1Department of Physiology, University of Pennsylvania School of Medicine, Philadelphia 19104-6085, USA.

Nature
|October 16, 1999
PubMed

Insights

Myosin VI, a molecular motor, moves towards the pointed end of actin filaments, unlike other myosins. This reverse movement is due to its lever arm rotating in the opposite direction.

Area of Science:

  • Molecular biology
  • Cellular mechanics
  • Biochemistry

Background:

  • Myosins and kinesins are ATP-hydrolyzing molecular motors that move along cellular tracks.
  • Conventional myosins move towards the barbed (+) end of actin filaments.
  • Kinesins exhibit diverse movement directions along microtubules.

Purpose of the Study:

  • To investigate the movement direction of myosin VI along actin filaments.
  • To elucidate the structural basis for myosin VI's unconventional motility.

Main Methods:

  • Cryo-electron microscopy was used to visualize myosin VI bound to actin.
  • Image analysis was employed to study conformational changes.
  • Structural comparison with other myosins was performed.

Main Results:

  • Myosin VI moves towards the pointed (-) end of actin filaments.
  • An ADP-mediated conformational change in myosin VI's distal domain (lever arm) was observed.
  • This conformational change occurs in the opposite direction compared to conventional myosins.

Conclusions:

  • Myosin VI achieves retrograde movement along actin filaments.
  • The opposite rotation of its lever arm is responsible for myosin VI's unique directionality.
  • This finding expands our understanding of myosin motor diversity and function.

More Related Videos

Fabrication of Carbon-Based Ionic Electromechanically Active Soft Actuators14:42

Fabrication of Carbon-Based Ionic Electromechanically Active Soft Actuators

Published on: April 25, 2020

Reconstitution of Actin-Based Motility with Commercially Available Proteins08:40

Reconstitution of Actin-Based Motility with Commercially Available Proteins

Published on: October 28, 2022

Related Concept Videos

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.
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...
The Movement of Organelles and Vesicles01:43

The Movement of Organelles and Vesicles

In eukaryotic cells,  cytoskeletal filaments such as actin, microtubules, and intermediate filaments form a mesh-like cytoskeletal network. These filaments serve as tracks for transporting cellular cargo. Specialized motor proteins use the chemical energy stored in adenosine triphosphate (ATP) for this transport. During interphase, microtubules are polarized, with the plus-end towards the cell periphery and the minus-end towards the cell center. Two microtubule-associated motor proteins,...
ATP Driven Pumps III: V-type Pumps01:30

ATP Driven Pumps III: V-type Pumps

V-type pumps are ATP-driven pumps found in the vacuolar membranes of plants, yeast, endosomal and lysosomal membranes of animal cells, plasma membranes of a few specialized eukaryotic cells, and some prokaryotes. They are also known as the V1Vo-ATPase, that couple ATP hydrolysis to transport protons against a concentration gradient.
The peripheral or cytosolic V1 domain with eight subunits is involved in ATP hydrolysis. The integral or transmembrane V0 domain containing at least five subunits...
Actin Polymerization and Cell Motility01:13

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.
Role of Myosin in Cell Migration01:18

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...