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Myosin VI: cellular functions and motor properties

Folma Buss1, Giulietta Spudich, John Kendrick-Jones

  • 1Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 2XY, United Kingdom. fb1@mole.bio.cam.ac.uk

Annual Review of Cell and Developmental Biology
|October 12, 2004
PubMed

Insights

Myosin VI, a unique motor protein, moves cargo along actin filaments towards the minus end. Its distinct monomeric and dimeric forms may regulate intracellular transport processes.

Area of Science:

  • Molecular Biology
  • Cell Biology

Background:

  • Myosin motor proteins are essential for intracellular transport, utilizing ATP hydrolysis to move cargo along actin filaments.
  • Myosin VI is an atypical myosin, moving towards the minus end of actin filaments, and plays roles in vesicular traffic, cell migration, and mitosis.

Purpose of the Study:

  • To investigate the functional significance of Myosin VI's distinct monomeric and dimeric motor states.
  • To understand how these different forms contribute to the regulation of intracellular transport pathways.

Main Methods:

  • In vitro biochemical assays were used to characterize the motor properties of Myosin VI.
  • Analysis focused on processive dimeric and nonprocessive monomeric forms, including their working stroke characteristics.

Main Results:

  • Myosin VI functions as both a processive dimeric motor and a nonprocessive monomeric motor in vitro.
  • Both forms exhibit a large working stroke, suggesting distinct functional capabilities.

Conclusions:

  • The dual capacity of Myosin VI to operate as monomeric or dimeric motor provides a potential regulatory mechanism for intracellular transport.
  • This adaptability allows for precise control over transport steps requiring either nonprocessive or processive motor activity.

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