CELL BIOLOGY:
Kinesin Movements Revealed
Elizabeth Pennisi
Last month, at the annual meeting of the American Society for Cell Biology, which was held in Washington, D.C., two groups of cell biologists described new results showing that two different kinesins, motor proteins that drag protein-laden vesicles along microscopic tracks called microtubules to the cell's periphery, move in very different ways. The classic "double-headed" kinesin studied by one group plods systematically step by step along the microtubules, whereas the single-headed variant kinesin studied by the other group ambles forward, relying on random movements to make progress.