Stirring up development with the heterotrimeric kinesin KIF3.

KIF3 is a heterotrimeric member of the kinesin superfamily of microtubule associated motors. This functionally diverse family of motor is involved in anterograde transport of membrane bound organelles in neurons and melanosomes, mediates transport between the endoplasmic reticulum and the Golgi, and transports protein complexes within cilia and flagella required for their morphogenesis. Interestingly, a mutation of KIF3, which impairs ciliogenesis in nodal cells, prevents the unidirectional leftward flow (nodal flow) of putative morphogens during embryogenesis, thereby altering the development of left-right asymmetry in mammals.