查看文章

To further elucidate the mechanism of organelle transport, we cloned a novel member of the mouse kinesin superfamily, KIFlB. This N-terminal-type motor protein is expressed ubiquitously in various kinds of tissues. In situ hybridization revealed that KlFl B is expressed abundantly in differentiated nerve cells. Interestingly, KlFlB works as a monomer, having a microtubule plus end-directed motility. Our rotary shadowing electron microscopy revealed mostly single globular structures. lmmunocytochemically, KlFl B was colocalized with mitochondria in vivo. Furthermore, a subcellular fractionation study showed that KIFlB was concentrated in the mitochondrial fraction, and purified KlFl B could transport mitochondria along microtubules in vitro. These data strongly suggested that KIFlB works as a monomeric motor for anterograde transport of mitochondria.