Simple centromere, complex kinetochore: linking spindle microtubules and centromeric DNA in budding yeast

Abstract

Although the budding yeast centromere is extremely short (125 bp) compared to those of other eukaryotes, the kinetochore that assembles on this DNA displays a rich molecular complexity. Here, we describe recent advances in our understanding of kinetochore function in budding yeast and present a model describing the attachment that is formed between spindle microtubules and centromeric DNA. This analysis may provide general principles for kinetochore function and regulation.

Figure 1.

Budding yeast kinetochore proteins and their homologues. Classification of budding yeast kinetochore proteins based on their function and interactions within the kinetochore. Essential genes are shown in red, and nonessential genes are shown in black. When applicable, the metazoan homologue of each protein is listed. For proteins with no identifiable metazoan homologue, the S. pombe homologue is listed in blue. In cases where kinetochore function has not been definitively established, that protein is indicated with a question mark.

Figure 2.

Schematic diagram of the kinetochore. This model is based on the organization of the DNA-binding proteins (Espelin et al., 1997; Meluh and Koshland, 1997; Meluh et al., 1998) and the known physical interactions of the different kinetochore proteins (Cheeseman et al., 2001a).