Deconvolution live-cell microscopy reveals the role of CDK1 kinase in regulating human chromosome-microtubule attachments

Abstract number
Presentation Form
Corresponding Email
[email protected]
Poster Session 1
Xinhong Song (1), Viji Draviam (1)
1. School of Biological and Chemical Sciences, Queen Mary University of London, London (UK)

high-resolution, time-lapse, deconvolution, Astrin, CDK1, Mps1, kinetochore

Abstract text

Bi-oriented attached chromosomes separate equally under the pulling force from opposing poles of the spindle; non-bioriented attachments are removed by Aurora-B mediated error correction pathway. But this opens a puzzle: before the formation of bi-oriented attachment, mono-oriented attachments should be protected from being destabilised by the error correction mechanism. However, how mature mono-oriented end-on attachment is recognised and preserved remains unclear. Tracking the dynamic localisation of the microtubule-associated protein, Astrin, with time-lapse deconvolution microscopy allows us to study the kinetochore composition and function. Quantitative analysis shows a distinct increase in the Astrin level on the mono-oriented end-on attached kinetochore following the inhibition of CDK1, a master mitotic kinase, independent of the error correction pathway mediated by Aurora-B. This suggests that CDK1 plays an important role in regulating outer kinetochore composition and mono-oriented attachment stability. What is more, unlike CDK1, the mitotic checkpoint complex member Mps1 does not regulate Astrin level at the end-on attached kinetochore. Here, we will present high-resolution 3D movie stills to show how the mitotic kinase CDK1, but not MPS1, negatively regulate Astrin recruitment at the kinetochore. The work provides insight into how cells protect the mature end-on kinetochore-microtubule attachment to ensure accurate chromosome segregation.