2. Academic Validation
  3. Mitotic phosphorylation by NEK6 and NEK7 reduces the microtubule affinity of EML4 to promote chromosome congression

Mitotic phosphorylation by NEK6 and NEK7 reduces the microtubule affinity of EML4 to promote chromosome congression

  • Sci Signal. 2019 Aug 13;12(594):eaaw2939. doi: 10.1126/scisignal.aaw2939.
Rozita Adib 1,  Jessica M Montgomery 1,  Joseph Atherton 2,  Laura O'Regan 1,  Mark W Richards 3,  Kees R Straatman 4,  Daniel Roth 5,  Anne Straube 5,  Richard Bayliss 3,  Carolyn A Moores 2,  Andrew M Fry 6
Affiliations

Affiliations

  • 1 Department of Molecular and Cell Biology, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK.
  • 2 Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, London WC1E 7HX, UK.
  • 3 Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK.
  • 4 Centre for Core Biotechnology Services, University of Leicester, University Road, Leicester LE1 7RH, UK.
  • 5 Centre for Mechanochemical Cell Biology and Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK.
  • 6 Department of Molecular and Cell Biology, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK. amf5@le.ac.uk.
PMID: 31409757 DOI: 10.1126/scisignal.aaw2939
Abstract

EML4 is a microtubule-associated protein that promotes microtubule stability. We investigated its regulation across the cell cycle and found that EML4 was distributed as punctate foci along the microtubule lattice in interphase but exhibited reduced association with spindle microtubules in mitosis. Microtubule sedimentation and cryo-electron microscopy with 3D reconstruction revealed that the basic N-terminal domain of EML4 mediated its binding to the acidic C-terminal tails of α- and β-tubulin on the microtubule surface. The mitotic kinases NEK6 and NEK7 phosphorylated the EML4 N-terminal domain at Ser144 and Ser146 in vitro, and depletion of these kinases in cells led to increased EML4 binding to microtubules in mitosis. An S144A-S146A double mutant not only bound inappropriately to mitotic microtubules but also increased their stability and interfered with chromosome congression. In addition, constitutive activation of NEK6 or NEK7 reduced the association of EML4 with interphase microtubules. Together, these data support a model in which NEK6- and NEK7-dependent phosphorylation promotes the dissociation of EML4 from microtubules in mitosis in a manner that is required for efficient chromosome congression.

Figures