Dynein-like cytoplasmic microtubule translocators

The eukaryotic flagellum presents an excellent predictive model of microtubule-mediated motility: movement is caused by microtubule translocators, called dyneins, which actively slide outer doublet microtubules against each other. Cytoplasmic movements, such as certain aspects of mitotic motion, may also be powered by dynein-like molecules. It is important, then, to carefully assess potential cytoplasmic dynein-like translocators by applying criteria defined by the properties of axonemal dynein. A cytoplasmic microtubule translocator may be only partially homologous to axonemal dynein; a modular construction may provide the translocator with domains that are shared with dynein, and with other domains that give it functional specificity. Finally, it is important to consider the possibility that a dynein-like enzyme that is found in the cytoplasm may not function in the cytoplasm but rather is awaiting incorporation into an axoneme.