Chromosome biorientation produces hundreds of piconewtons at a metazoan kinetochore

• Published in: Nature communications Vol. 7; no. 1; p. 13221
• Main Authors: Ye, Anna A., Cane, Stuart, Maresca, Thomas J.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 20.10.2016; Nature Publishing Group; Nature Portfolio
• Subjects: 13/106; 14; 14/19; 14/33; 14/35; 14/63; 38/89; 631/337/103/1966; 631/337/641/1966; 631/80/103/1966; 631/80/641/1966; 64/24; Cell division; Chromosomes; Humanities and Social Sciences; Insects; multidisciplinary; Proteins; Science; Science (multidisciplinary); Sensors; United States > US; Massachusetts
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms13221

High-fidelity transmission of the genome through cell division requires that all sister kinetochores bind to dynamic microtubules (MTs) from opposite spindle poles. The application of opposing forces to this bioriented configuration produces tension that stabilizes kinetochore–microtubule (kt–MT) attachments. Defining the magnitude of force that is applied to kinetochores is central to understanding the mechano-molecular underpinnings of chromosome segregation; however, existing kinetochore force measurements span orders of magnitude. Here we measure kinetochore forces by engineering two calibrated force sensors into the Drosophila kinetochore protein centromere protein (CENP)-C. Measurements of both reporters indicate that they are, on average, under ∼1–2 piconewtons (pNs) of force at metaphase. Based on estimates of the number of CENP-C molecules and MTs per Drosophila kinetochore and envisioning kinetochore linkages arranged such that they distribute forces across them, we propose that kinetochore fibres (k-fibres) exert hundreds of pNs of poleward-directed force to bioriented kinetochores. Chromosomes bind microtubules (MT) from opposite spindle poles and the generated tension stabilizes kinetochore-MT attachments. Here the authors measure kinetochore forces by engineering two force sensors and propose that kinetochore fibers exert hundreds of pNs of force to bioriented kinetochores.