Flexural stiffness of myosin Va subdomains as measured from tethered particle motion

Research output: Contribution to journalArticle

Authors

  • Arthur J. Michalek
  • Guy G. Kennedy
  • David M. Warshaw
  • M. Yusuf Ali

External Institution(s)

  • University of Vermont
  • Clarkson University

Details

Original languageEnglish (US)
Article number465693
JournalJournal of Biophysics
Volume2015
StatusPublished - Jan 1 2015
Peer-reviewedYes

Abstract

Myosin Va (MyoVa) is a processive molecular motor involved in intracellular cargo transport on the actin cytoskeleton. The motor's processivity and ability to navigate actin intersections are believed to be governed by the stiffness of various parts of the motor's structure. Specifically, changes in calcium may regulate motor processivity by altering the motor's lever arm stiffness and thus its interhead communication. In order to measure the flexural stiffness of MyoVa subdomains, we use tethered particle microscopy, which relates the Brownian motion of fluorescent quantum dots, which are attached to various single- and double-headed MyoVa constructs bound to actin in rigor, to the motor's flexural stiffness. Based on these measurements, the MyoVa lever arm and coiled-coil rod domain have comparable flexural stiffness (0.034 pN/nm). Upon addition of calcium, the lever arm stiffness is reduced 40% as a result of calmodulins potentially dissociating from the lever arm. In addition, the flexural stiffness of the full-length MyoVa construct is an order of magnitude less stiff than both a single lever arm and the coiled-coil rod. This suggests that the MyoVa lever arm-rod junction provides a flexible hinge that would allow the motor to maneuver cargo through the complex intracellular actin network.

Citation formats

APA

Michalek, A. J., Kennedy, G. G., Warshaw, D. M., & Ali, M. Y. (2015). Flexural stiffness of myosin Va subdomains as measured from tethered particle motion. Journal of Biophysics, 2015, [465693]. https://doi.org/10.1155/2015/465693

Harvard

Michalek, AJ, Kennedy, GG, Warshaw, DM & Ali, MY 2015, 'Flexural stiffness of myosin Va subdomains as measured from tethered particle motion', Journal of Biophysics, vol. 2015, 465693. https://doi.org/10.1155/2015/465693