To understand the physics of muscle contraction and molecular motor movement, we develop a model for nonequilibrium free energy transduction based on a diffusion in a periodic force field. It is shown that a nonconservative force is sufficient and necessary for a steady state with circular flux, but is not sufficient for a global unidirectional transport synonymous to motor protein movement. A ...

Motor proteins that couple ATP hydrolysis to movement along nucleic acids play a variety of essential roles in DNA metabolism. Often these enzymes function as components of macromolecular complexes, and DNA translocation by the motor protein drives movement of other components of the complex. In order to understand how the activity of motor proteins is regulated within multi-protein complexes w...

There is accumulating evidence from behavioral, neurophysiological, and neuroimaging studies that the acquisition of motor skills involves both perceptual and motor learning. Perceptual learning alters movements, motor learning, and motor networks of the brain. Motor learning changes perceptual function and the sensory circuits of the brain. Here, we review studies of both human limb movement a...

Proper alignment of duplicated chromosomes at the metaphase plate involves both motor-driven chromosome movement and the functional and physical end-on connection (K-fiber formation) between the kinetochore and the plus-end of microtubules. The B56 family of protein phosphatase 2A (PP2A) regulatory subunits (B56-PP2A), through their interaction with the mitotic checkpoint protein BUBR1, are req...

The processive movement of the dimeric motor protein kinesin 1 along microtubules requires communication between the two motor domains. Yildiz et al. (2008) now show that tension between the motor domains not only is necessary for normal processivity but also may be sufficient for motor motility under some conditions.

The yeast kinesin motor protein Kar3 forms a heterodimer with a nonmotor protein Vik1. A study in this issue by Allingham et al. (2007) reveals that Vik1 unexpectedly has a structure similar to a kinesin motor domain yet lacks a nucleotide-binding site and is thus catalytically inactive. However, this does not hinder movement of the heterodimer because other features of the remarkably divergent...

Objectives: Movement is a continuous aspect of life and an important factor to achieve the goals and meet the needs. Regarding the importance of infantś motor assessment and the large number of children with motor disorders, a valid and reliable test is required to help evaluation of motor development and provide appropriate interventions by therapists and educators. This study was implemented ...