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Multisite phosphorylation of C-Nap1 releases it from Cep135 to trigger centrosome disjunction

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posted on 18.07.2014, 10:59 by Tara Hardy, Miseon Lee, Rebecca S. Hames, Suzanna L. Prosser, Donna-Marie Cheary, Mugdha D. Samant, Francisca Schultz, Joanne E. Baxter, Kunsoo Rhee, Andrew M. Fry
During mitotic entry, centrosomes separate to establish the bipolar spindle. Delays in centrosome separation can perturb chromosome segregation and promote genetic instability. However, interphase centrosomes are physically tethered by a proteinaceous linker composed of C-Nap1 (also known as CEP250) and the filamentous protein rootletin. Linker disassembly occurs at the onset of mitosis in a process known as centrosome disjunction and is triggered by the Nek2-dependent phosphorylation of C-Nap1. However, the mechanistic consequences of C-Nap1 phosphorylation are unknown. Here, we demonstrate that Nek2 phosphorylates multiple residues within the C-terminal domain of C-Nap1 and, collectively, these phosphorylation events lead to loss of oligomerization and centrosome association. Mutations in non-phosphorylatable residues that make the domain more acidic are sufficient to release C-Nap1 from the centrosome, suggesting that it is an increase in overall negative charge that is required for this process. Importantly, phosphorylation of C-Nap1 also perturbs interaction with the core centriolar protein, Cep135, and interaction of endogenous C-Nap1 and Cep135 proteins is specifically lost in mitosis. We therefore propose that multisite phosphorylation of C-Nap1 by Nek2 perturbs both oligomerization and Cep135 interaction, and this precipitates centrosome disjunction at the onset of mitosis.

History

Citation

Journal of Cell Science, 2014, 127, pp. 2493-2506

Author affiliation

/Organisation/COLLEGE OF MEDICINE, BIOLOGICAL SCIENCES AND PSYCHOLOGY/School of Biological Sciences/Department of Biochemistry

Version

VoR (Version of Record)

Published in

Journal of Cell Science

Publisher

The Company of Biologists Ltd

issn

0021-9533

eissn

1477-9137

Copyright date

2014

Available date

18/07/2014

Publisher version

http://jcs.biologists.org/content/127/11/2493

Notes

PMCID: PMC4038944

Language

en

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