Reconstitution reveals two paths of force transmission through the kinetochore

Partitioning duplicated chromosomes equally between daughter cells is a microtubule-mediated process essential to eukaryotic life. A multi-protein machine, the kinetochore, drives chromosome segregation by coupling the chromosomes to dynamic microtubule tips, even as the tips grow and shrink through the gain and loss of subunits. The kinetochore must harness, transmit, and sense mitotic forces, as a lack of tension signals incorrect chromosome-microtubule attachment and precipitates error correction mechanisms. But though the field has arrived at a 'parts list' of dozens of kinetochore proteins organized into subcomplexes, the path of force transmission through these components has remained unclear. Here we report reconstitution of functionalSaccharomyces cerevisiaekinetochore assemblies from recombinantly expressed proteins. The reconstituted kinetochores are capable of self-assemblingin vitro, coupling centromeric nucleosomes to dynamic microtubules, and withstanding mitotically relevant forces. They reveal two distinct pathways of force transmission and Ndc80c recruitment.
Source: eLife - Category: Biomedical Science Tags: Biochemistry and Chemical Biology Cell Biology Source Type: research