Cyclin A/Cdk1 modulates Plk1 activity in prometaphase to regulate kinetochore-microtubule attachment stability

Elife. 2017 Nov 20:6:e29303. doi: 10.7554/eLife.29303.


The fidelity of chromosome segregation in mitosis is safeguarded by the precise regulation of kinetochore microtubule (k-MT) attachment stability. Previously, we demonstrated that Cyclin A/Cdk1 destabilizes k-MT attachments to promote faithful chromosome segregation. Here, we use quantitative phosphoproteomics to identify 156 Cyclin A/Cdk1 substrates in prometaphase. One Cyclin A/Cdk1 substrate is myosin phosphatase targeting subunit 1 (MYPT1), and we show that MYPT1 localization to kinetochores depends on Cyclin A/Cdk1 activity and that MYPT1 destabilizes k-MT attachments by negatively regulating Plk1 at kinetochores. Thus, Cyclin A/Cdk1 phosphorylation primes MYPT1 for Plk1 binding. Interestingly, priming of PBIP1 by Plk1 itself (self-priming) increased in MYPT1-depleted cells showing that MYPT1 provides a molecular link between the processes of Cdk1-dependent priming and self-priming of Plk1 substrates. These data demonstrate cross-regulation between Cyclin A/Cdk1-dependent and Plk1-dependent phosphorylation of substrates during mitosis to ensure efficient correction of k-MT attachment errors necessary for high mitotic fidelity.

Keywords: Plk1; cell biology; cyclin dependent kinase; human; kinetochore; microtubule; mitosis.

MeSH terms

  • CDC2 Protein Kinase / metabolism*
  • Cell Cycle Proteins / metabolism*
  • Cell Line
  • Chromosome Segregation
  • Cyclin A / metabolism*
  • Humans
  • Kinetochores / metabolism*
  • Microtubules / metabolism*
  • Myosin-Light-Chain Phosphatase / metabolism*
  • Phosphorylation
  • Prometaphase*
  • Protein Processing, Post-Translational
  • Protein Serine-Threonine Kinases / metabolism*
  • Proto-Oncogene Proteins / metabolism*


  • Cell Cycle Proteins
  • Cyclin A
  • Proto-Oncogene Proteins
  • Protein Serine-Threonine Kinases
  • polo-like kinase 1
  • CDC2 Protein Kinase
  • CDK1 protein, human
  • Myosin-Light-Chain Phosphatase
  • PPP1R12A protein, human