Dissection of kinesin's processivity.

The protein family of kinesins contains processive motor proteins that move stepwise along microtubules. This mechanism requires the precise coupling of the catalytic steps in the two heads, and their precise mechanical coordination. Here we show that these functionalities can be uncoupled in chimera of processive and non-processive kinesins.

Effect of spastic paraplegia mutations in KIF5A kinesin on transport activity.

Hereditary spastic paraplegia (HSP) is a neurodegenerative disease caused by motoneuron degeneration. It is linked to at least 30 loci, among them SPG10, which causes dominant forms and originates in point mutations in the neuronal Kinesin-1 gene (KIF5A). Here, we investigate the motility of KIF5A and four HSP mutants.

Myosin-V is a mechanical ratchet.

Myosin-V is a linear molecular motor that hydrolyzes ATP to move processively toward the plus end of actin filaments. Motion of this motor under low forces has been studied recently in various single-molecule assays. In this paper we show that myosin-V reacts to high forces as a mechanical ratchet.

Flexibility of the neck domain enhances Kinesin-1 motility under load.

Kinesin-1 is a dimeric motor protein that moves stepwise along microtubules. A two-stranded alpha-helical coiled-coil formed by the neck domain links the two heads of the molecule, and forces the motor heads to alternate. By exchanging the particularly soft neck region of the conventional kinesin from the fungus Neurospora crassa with an artificial, highly stable coiled-coil we investigated how this domain affects motor kinetics and motility.

Force-dependent stepping kinetics of myosin-V.

Myosin-V is a processive two-headed actin-based motor protein involved in many intracellular transport processes. A key question for understanding myosin-V function and the communication between its two heads is its behavior under load. Since in vivo myosin-V colocalizes with other much stronger motors like kinesins, its behavior under superstall forces is especially relevant.