Kinesin-14 proteins have a C-terminal motor domain. At least four members of the group (Dm Ncd, Sc KAR3, Cg CHO2, At KCBP) have been demonstrated to be minus-end directed motors (Walker et al. 1990), in contrast to the usual plus-end directed motility of other kinesin proteins.
During spindle formation, Kinesin-14 cross-links antiparallel microtubules and slides them together (thereby generating inward forces) to balance the outward forces generated by plus-end-directed kinesins of the Kinesin-5 family. Kinesin-14 family members also gather microtubule minus-ends and focus them into spindle poles. Mutation or inhibition of Kinesin-14 family members often results in disordered or splayed meiotic spindle poles (Ambrose et al. 2005).