Molecular motors are proteins made up of amino acids like any other protein in a cell.
They move along tiny filaments, called microtubules, as they transport vesicles around the cell or herd chromosomes during cell division. Most motors move toward the fast-growing end of these microtubules, but some move toward the opposite, more stable end of the microtubules. Until now, it was thought that these motors could only do one or the other. Scientists believe that malfunctioning molecular motors might be responsible for some diseases caused by incorrect distribution of chromosomes during cell division, such as Down syndrome. By understanding how motors work, how they organize chromosomes and how they lead the cell through the division process, researchers hope to be able to understand what causes these diseases and how to prevent them.