M. Nangaku et al., KIF1B, A NOVEL MICROTUBULE PLUS END-DIRECTED MONOMERIC MOTOR PROTEIN FOR TRANSPORT OF MITOCHONDRIA, Cell, 79(7), 1994, pp. 1209-1220
To further elucidate the mechanism of organelle transport, we cloned a
navel member of the mouse kinesin superfamily, KIF1B. This N-terminal
-type motor protein is expressed ubiquitously in various kinds of tiss
ues. In situ hybridization revealed that KIF1B is expressed abundantly
in differentiated nerve cells. Interestingly, KIF1B works as a monome
r, having a microtubule plus end-directed motility, Our rotary shadowi
ng electron microscopy revealed mostly single globular structures. Imm
unocytochemically, KIF1B was colocalized with mitochondria in vivo. Fu
rthermore, a subcellular fractionation study showed that KIF1B was con
centrated in the mitochondrial fraction, and purified KIF1B could tran
sport mitochondria along microtubules in vitro. These data strongly su
ggested that KIF1B works as a monomeric motor for anterograde transpor
t of mitochondria.