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Direct observation of processive movement by individual myosin V molecules

T Sakamoto1, I Amitani, E Yokota

  • 1Department of Physics, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa-ken, 920-1192, Japan.

Biochemical and Biophysical Research Communications
|June 2, 2000
PubMed

Insights

Individual chick brain myosin V (BMV) molecules demonstrated highly processive movement along actin filaments. This provides direct evidence for BMV

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Biophysics

Background:

  • Myosin V is an unconventional myosin implicated in intracellular transport.
  • Previous studies suggested high processivity, but direct observation was lacking.

Purpose of the Study:

  • To provide direct evidence for the high processivity of native chick brain myosin V (BMV) molecules.
  • To characterize the movement dynamics of individual BMV molecules.

Main Methods:

  • Utilized single-molecule imaging of fluorescently labeled native chick brain myosin V (BMV).
  • Observed BMV interaction with actin filaments immobilized on a coverslip.

Main Results:

  • Individual BMV molecules exhibited highly processive movement along actin filaments.
  • BMV moved processively towards the barbed end of actin, with minimal detachment.
  • Observed maximum speeds of 1 microm/s and actin-activated ATPase rates of 2.4 s(-1).

Conclusions:

  • Direct observation confirms the highly processive nature of BMV.
  • BMV likely travels approximately 400 nm per ATPase cycle, supporting its role in long-range transport.

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