Kinesin Family, Member 1B (KIF1B)

Kif1b was expressed in all tissues tested. In situ hybridization revealed that Kif1b was expressed abundantly in differentiated nerve cells.Northern blot analysis demonstrated that human KIF1B has at least 2 isoforms. The long isoform (KIF1B-beta) was expressed in a wide variety of tissues, while the short isoform (KIF1B-alpha) was detected only in adult testis.Rotary shadowing electron microscopy revealed mostly single globular structures. Immunocytochemically, Kif1b was colocalized with mitochondria in vivo. A subcellular fractionation study showed that Kif1b was concentrated in the mitochondrial fraction, and purified Kif1b could transport mitochondria along microtubules in vitro. These data suggested that Kif1b works as a monomeric motor for anterograde transport of mitochondria.