The unconventional kinetoplastid kinetochore: from discovery toward functional understanding.

Bungo Akiyoshi

doi:10.1042/bst20160112

Abstract

The kinetochore is the macromolecular protein complex that drives chromosome segregation in eukaryotes. Its most fundamental function is to connect centromeric DNA to dynamic spindle microtubules. Studies in popular model eukaryotes have shown that centromere protein (CENP)-A is critical for DNA-binding, whereas the Ndc80 complex is essential for microtubule-binding. Given their conservation in diverse eukaryotes, it was widely believed that all eukaryotes would utilize these components to make up a core of the kinetochore. However, a recent study identified an unconventional type of kinetochore in evolutionarily distant kinetoplastid species, showing that chromosome segregation can be achieved using a distinct set of proteins. Here, I review the discovery of the two kinetochore systems and discuss how their studies contribute to a better understanding of the eukaryotic chromosome segregation machinery.

Highlights

Faithful transmission of genetic information from generation to generation is essential for the survival of all organisms
Chromosome replication occurs during S phase and duplicated chromosomes are physically connected by the cohesin complex [1] (Figure 1)
Chromosome segregation is directed by the kinetochore, the proteinaceous structure that assembles onto the centromeric DNA and interacts with spindle microtubules during mitosis and meiosis [2,3,4,5]

Summary

Introduction

Faithful transmission of genetic information from generation to generation is essential for the survival of all organisms. Chromosome segregation is directed by the kinetochore, the proteinaceous structure that assembles onto the centromeric DNA and interacts with spindle microtubules during mitosis and meiosis [2,3,4,5]. This was a very exciting finding because it revealed that CENP-A is a DNA-binding protein and suggested a possible mechanism for how kinetochore positions could be epigenetically inherited [47,48].

Results

Conclusion