Cdk1 regulates centrosome separation by restraining proteolysis of microtubule-associated proteins

Karen Crasta, Phillips Huang, Garry Morgan, Mark Winey, Uttam Surana

Research output: Contribution to journalArticlepeer-review

63 Scopus citations


In yeast, separation of duplicated spindle pole bodies (SPBs) (centrosomes in higher eukaryotes) is an indispensable step in the assembly of mitotic spindle and is triggered by severing of the bridge that connects the sister SPBs. This process requires Cdk1 (Cdc28) activation by Tyrosine 19 dephosphorylation. We show that cells that fail to activate Cdk1 are devoid of spindles due to persistently active APCCdh1, which targets microtubule-associated proteins Cin8, Kip1 and Ase1 for degradation. Tyrosine 19 dephosphorylation of Cdk1 is necessary to specifically prevent proteolysis of these proteins. Interestingly, SPB separation is dependent on the microtubule-bundling activity of Cin8 but not on its motor function. Since ectopic expression of proteolysis-resistant Cin8, Kip1 or Ase1 is sufficient for SPB separation even in the absence of Cdc28-Clb activity, we suggest that stabilization of these mechanical force-generating proteins is the predominant role of Cdc28-Clb in centrosome separation.

Original languageEnglish (US)
Pages (from-to)2551-2563
Number of pages13
JournalEMBO Journal
Issue number11
StatePublished - Jul 7 2006
Externally publishedYes


  • Cdh1
  • Centrosomes
  • Mitosis
  • SPB
  • Spindle

ASJC Scopus subject areas

  • Neuroscience(all)
  • Molecular Biology
  • Biochemistry, Genetics and Molecular Biology(all)
  • Immunology and Microbiology(all)


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