Zwilch, Kinetochore Associated Homolog (ZWILCH)

Williams et al. (2003) identified a novel protein in Drosophila, which they designated Zwilch, that associates with Sw10 and Rod (KNTC1) in a complex that recruits cytoplasmic dynein to the kinetochore and participates in the spindle checkpoint. They isolated a Zwilch mutant that exhibits the same mitotic phenotypes associated with Zw10 and Rod mutations: lagging chromosomes at anaphase and precocious sister-chromatid separation upon activation of the spindle checkpoint. ZWILCH forms a complex with SW10 and KNTC1. Like SW10 and KNTC1, ZWILCH is recruited to the kinetochores early in prophase, where it localizes through metaphase. Unlike all 3 proteins in Drosophila and human SW10 and KNTC1, however, ZWILCH was not detected on kinetochore microtubules during metaphase or on kinetochores during anaphase.