Mechanics of motility: distinct dynein binding domains on alpha- and beta-tubulin

Biochem Cell Biol. Sep-Oct 1995;73(9-10):665-71. doi: 10.1139/o95-074.


Microtubules (MTs) interact with force-generating proteins to generate a variety of intracellular movements, including intracellular particle transport, ciliary-flagellar beating, and chromosome-spindle movements during mitosis-meiosis. Relatively little is known about the mechanics of these motor-MT interactions, in part because the motor binding domains of the MT and the corresponding MT binding domains of the motor have not been well characterized. Using a flagellar motility assay, we report that the MT subunits, alpha- and beta-tubulin, each contain a dynein binding domain located near the C-termini of their respective tubulin subunits. Blocking either alpha- or beta-tubulin binding domains of dynein attenuates motility in demembranated sea urchin sperm up to 50%. Interestingly, blocking both alpha- and beta-tubulin binding domains on dynein produces much greater decreases in motility. These data suggest that flagellar dynein binds to both subunits of the MT polymer, alpha- and beta-tublin. In addition, the two subunits appear to contribute equivalent, but functionally separate, roles to flagellar motility.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Dyneins / chemistry*
  • Male
  • Protein Binding
  • Protein Structure, Tertiary*
  • Sea Urchins
  • Sperm Motility / physiology*
  • Tubulin / chemistry*


  • Tubulin
  • Dyneins