title: One-dimensional diffusion of microtubules bound to flagellar dynein.
abstract: Dynein is a multisubunit ATPase that powers microtubule-based motility. We find that a dissociated dynein particle containing the beta heavy chain subunit translocates microtubules unidirectionally over a glass surface in the presence of ATP. However, after nucleotide hydrolysis is inhibited by vanadate, unidirectional translocation ceases, and microtubules instead undergo irregular back-and-forth motion along their longitudinal axes. Quantitative analysis reveals that this motion is due to thermal-driven diffusion, but, unlike a particle undergoing Brownian motion, the diffusion is restricted to one dimension. The properties of the diffusional movement indicate that dynein can interact with microtubules in a way that permits the latter to diffuse only along their longitudinal axes. This weak binding interaction may constitute an important intermediate state in dynein's force-generating cycle.
authors.affiliation: Department of Pharmacology, University of California School of Medicine, San Francisco 94143.
authors.forename: R D
authors.initials: RD
authors.lastname: Vale
authors.forename: D R
authors.initials: DR
authors.lastname: Soll
authors.forename: I R
authors.initials: IR
authors.lastname: Gibbons
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D004058:Diffusion; D004398:Dyneins / Q000378:metabolism*; D046911:Macromolecular Substances; D008297:Male; D008870:Microtubules / Q000502:physiology* / Q000648:ultrastructure; D012617:Sea Urchins; D013081:Sperm Motility; D013082:Sperm Tail / Q000201:enzymology*; D013094:Spermatozoa / Q000201:enzymology*
chemical_list: D046911:Macromolecular Substances; D000251:Adenosine Triphosphatases; D004398:Dyneins