SWAP, SWITCH, and STABILIZE: Mechanisms of Kinetochore-Microtubule Error Correction

For correct chromosome segregation in mitosis, eukaryotic cells must establish chromosome biorientation where sister kinetochores attach to microtubules extending from opposite spindle poles. To establish biorientation, any aberrant kinetochore-microtubule interactions must be resolved in the process called error correction. For resolution of the aberrant interactions in error correction, kinetochore-microtubule interactions must be exchanged until biorientation is formed (the SWAP process). At initiation of biorientation, the state of weak kinetochore-microtubule interactions should be converted to the state of stable interactions (the SWITCH process)-the conundrum of this conversion is called the initiation problem of biorientation. Once biorientation is established, tension is applied on kinetochore-microtubule interactions, which stabilizes the interactions (the STABILIZE process). Aurora B kinase plays central roles in promoting error correction, and Mps1 kinase and Stu2 microtubule polymerase also play important roles. In this article, we review mechanisms of error correction by considering the SWAP, SWITCH, and STABILIZE processes. We mainly focus on mechanisms found in budding yeast, where only one microtubule attaches to a single kinetochore at biorientation, making the error correction mechanisms relatively simpler.

Automated summary

This article discusses how eukaryotic cells ensure correct chromosome segregation during mitosis, focusing on the mechanisms of error correction through the SWAP, SWITCH, and STABILIZE processes. Key players in this process include Aurora B kinase, Mps1 kinase, and Stu2 microtubule polymerase. The study mainly examines mechanisms in budding yeast, where error correction mechanisms are relatively simpler due to a single microtubule attachment at biorientation.