Scientific article
Open access

The Ska complex promotes Aurora B activity to ensure chromosome biorientation

Published inThe Journal of Cell Biology, vol. 215, no. 1, p. 77-93
Publication date2016

Chromosome biorientation and accurate segregation rely on the plasticity of kinetochore-microtubule (KT-MT) attachments. Aurora B facilitates KT-MT dynamics by phosphorylating kinetochore proteins that are critical for KT-MT interactions. Among the substrates whose microtubule and kinetochore binding is curtailed by Aurora B is the spindle and kinetochore-associated (Ska) complex, a key factor for KT-MT stability. Here, we show that Ska is not only a substrate of Aurora B, but is also required for Aurora B activity. Ska-deficient cells fail to biorient and display chromosome segregation errors underlying suppressed KT-MT turnover. These defects coincide with KNL1-Mis12-Ndc80 network hypophosphorylation, reduced mitotic centromere-associated kinesin localization, and Aurora B T-loop phosphorylation at kinetochores. We further show that Ska requires its microtubule-binding capability to promote Aurora B activity in cells and stimulates Aurora B catalytic activity in vitro. Finally, we show that protein phosphatase 1 counteracts Aurora B activity to enable Ska kinetochore accumulation once biorientation is achieved. We propose that Ska promotes Aurora B activity to limit its own microtubule and kinetochore association and to ensure that KT-MT dynamics and stability fall within an optimal balance for biorientation.

  • Aurora Kinase B/metabolism
  • Biocatalysis
  • Centromere/metabolism
  • Chromosomal Proteins
  • Non-Histone/metabolism
  • Chromosome Positioning
  • Chromosome Segregation
  • HeLa Cells
  • Humans
  • Kinetochores/metabolism
  • Microtubules/metabolism
  • Multiprotein Complexes/metabolism
  • Phosphorylation
  • Protein Phosphatase 1/metabolism
  • Swiss National Science Foundation - 31003A 160006
Citation (ISO format)
REDLI, Patrick M et al. The Ska complex promotes Aurora B activity to ensure chromosome biorientation. In: The Journal of Cell Biology, 2016, vol. 215, n° 1, p. 77–93. doi: 10.1083/jcb.201603019
Main files (1)
Article (Published version)
ISSN of the journal0021-9525

Technical informations

Creation09/10/2017 11:44:00 PM
First validation09/10/2017 11:44:00 PM
Update time03/15/2023 2:25:56 AM
Status update03/15/2023 2:25:56 AM
Last indexation10/19/2023 7:14:26 AM
All rights reserved by Archive ouverte UNIGE and the University of GenevaunigeBlack