Driving chromosome segregation: lessons from the human and Drosophila centromere–kinetochore machinery

The kinetochore is a complex molecular machine that serves as the interface between sister chromatids and the mitotic spindle. The kinetochore assembles at a particular chromosomal locus, the centromere, which is essential to maintain genomic stability during cell division. The kinetochore is a macromolecular puzzle of subcomplexes assembled in a hierarchical manner and fulfils three main functions: microtubule attachment, chromosome and sister chromatid movement, and regulation of mitotic progression though the spindle assembly checkpoint. In the present paper we compare recent results on the assembly, organization and function of the kinetochore in human and Drosophila cells and conclude that, although essential functions are highly conserved, there are important differences that might help define what is a minimal chromosome segregation machinery.