Self-regulated Plk1 recruitment to kinetochores by the Plk1-PBIP1 interaction is critical for proper chromosome segregation

Mol Cell. 2006 Nov 3;24(3):409-22. doi: 10.1016/j.molcel.2006.10.016.


The polo-box domain (PBD) of mammalian polo-like kinase 1 (Plk1) is essential in targeting its catalytic activity to specific subcellular structures critical for mitosis. The mechanism underlying Plk1 recruitment to the kinetochores and the role of Plk1 at this site remain elusive. Here, we demonstrate that a PBD-binding protein, PBIP1, is crucial for recruiting Plk1 to the interphase and mitotic kinetochores. Unprecedentedly, Plk1 phosphorylated PBIP1 at T78, creating a self-tethering site that specifically interacted with the PBD of Plk1, but not Plk2 or Plk3. Later in mitosis, Plk1 also induced PBIP1 degradation in a T78-dependent manner, thereby enabling itself to interact with other components critical for proper kinetochore functions. Absence of the p-T78-dependent Plk1 localization induced a chromosome congression defect and compromised the spindle checkpoint, ultimately leading to aneuploidy. Thus, Plk1 self-regulates the Plk1-PBIP1 interaction to timely localize to the kinetochores and promote proper chromosome segregation.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural

MeSH terms

  • Amino Acid Motifs
  • Amino Acid Sequence
  • Carrier Proteins / chemistry
  • Carrier Proteins / metabolism*
  • Cell Cycle Proteins / metabolism*
  • Chromosome Segregation / genetics*
  • Epitopes / metabolism
  • HeLa Cells
  • Humans
  • Kinetochores / metabolism*
  • Models, Biological
  • Molecular Sequence Data
  • Phosphorylation
  • Prometaphase / physiology
  • Prophase / physiology
  • Protein Binding
  • Protein Processing, Post-Translational
  • Protein Structure, Tertiary
  • Protein Transport
  • Protein-Serine-Threonine Kinases / metabolism*
  • Proteins / chemistry
  • Proteins / metabolism*
  • Proto-Oncogene Proteins / metabolism*
  • Serine / metabolism
  • Spindle Apparatus / metabolism
  • Threonine / metabolism


  • Carrier Proteins
  • Cell Cycle Proteins
  • Epitopes
  • Proteins
  • Proto-Oncogene Proteins
  • Threonine
  • Serine
  • Protein-Serine-Threonine Kinases
  • polo-like kinase 1