Differential Regulation of Dynein and Kinesin Motor Proteins by Tau.
Dixit, Ram; Ross, Jennifer L. *; Goldman, Yale E.; Holzbaur, Erika L. F. +
[Report]
Science.
319(5866):1086-1089, February 22, 2008.
(Format: HTML)
Dynein and kinesin motor proteins transport cellular cargoes toward opposite ends of microtubule tracks. In neurons, microtubules are abundantly decorated with microtubule-associated proteins (MAPs) such as tau. Motor proteins thus encounter MAPs frequently along their path. To determine the effects of tau on dynein and kinesin motility, we conducted single-molecule studies of motor proteins moving along tau-decorated microtubules. Dynein tended to reverse direction, whereas kinesin tended to detach at patches of bound tau. Kinesin was inhibited at about a tenth of the tau concentration that inhibited dynein, and the microtubule-binding domain of tau was sufficient to inhibit motor activity. The differential modulation of dynein and kinesin motility suggests that MAPs can spatially regulate the balance of microtubule-dependent axonal transport.
Copyright (C) 2008 by the American Association for the Advancement of Science