Differential Regulation of Dynein and Kinesin
Motor Proteins by Tau.
Science. 319:1086-1089. 2008.
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.