Two Saccharomyces cerevisiae kinesin-related gene products required for mitotic spindle assembly

Saccharomyces cerevisiae genes KIP1 and CIN8 are kinesin domain-containing genes which are involved in mitotic spindle assembly. The genes were expressed and their proteins, Kip1p and Cin8p, were further characterized. The results showed that Kip1p and Cin8p perform essential but overlapping functions. Cin8p is required for pole separation during mitotic spindle assembly, and is a component of the mitotic spindle. Furthermore, at least one of the two proteins are required to separate duplicated spindle poles during the assembly of the mitotic spindle. Both proteins appear to interact with the spindle microtubules to generate the force required for separation.