Bead Movement by Kinesin

Movement of plastic beads by kinesin, a molecular motor protein. Many cargoes (organelles, RNAs and proteins) are transported within cells along microtubule tracks by molecular motor proteins. This motion can be reconstituted with purified proteins in a "test tube". Here a molecular motor protein called kinesin is attached to a plastic bead that is 1 micron in size (one-millionth of a meter) and these motors transport the plastic beads along a microtubule track (made from purified tubulin). This video is shown in "real time" and the motion occurs at a rate of 0.5 microns per second. Credit: Ron Vale (UCSF)