Degradation of Cep68 and PCNT cleavage mediate Cep215 removal from the PCM to allow centriole separation, disengagement and licensing

Nat Cell Biol. 2015 Jan;17(1):31-43. doi: 10.1038/ncb3076. Epub 2014 Dec 15.


An intercentrosomal linker keeps a cell's two centrosomes joined together until it is dissolved at the onset of mitosis. A second connection keeps daughter centrioles engaged to their mothers until they lose their orthogonal arrangement at the end of mitosis. Centriole disengagement is required to license centrioles for duplication. We show that the intercentrosomal linker protein Cep68 is degraded in prometaphase through the SCF(βTrCP) (Skp1-Cul1-F-box protein) ubiquitin ligase complex. Cep68 degradation is initiated by PLK1 phosphorylation of Cep68 on Ser 332, allowing recognition by βTrCP. We also found that Cep68 forms a complex with Cep215 (also known as Cdk5Rap2) and PCNT (also known as pericentrin), two PCM (pericentriolar material) proteins involved in centriole engagement. Cep68 and PCNT bind to different pools of Cep215. We propose that Cep68 degradation allows Cep215 removal from the peripheral PCM preventing centriole separation following disengagement, whereas PCNT cleavage mediates Cep215 removal from the core of the PCM to inhibit centriole disengagement and duplication.

MeSH terms

  • Antigens / metabolism*
  • Cell Cycle Proteins / antagonists & inhibitors
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism
  • Cell Line, Tumor
  • Centrioles / genetics*
  • HEK293 Cells
  • HeLa Cells
  • Humans
  • Intracellular Signaling Peptides and Proteins / metabolism*
  • Metaphase / genetics
  • Microtubule-Associated Proteins / genetics*
  • Microtubule-Associated Proteins / metabolism*
  • Nerve Tissue Proteins / metabolism*
  • Phosphorylation
  • Prometaphase / genetics
  • Protein Binding
  • Protein Serine-Threonine Kinases / antagonists & inhibitors
  • Protein Serine-Threonine Kinases / genetics
  • Protein Serine-Threonine Kinases / metabolism
  • Proteolysis*
  • Proto-Oncogene Proteins / antagonists & inhibitors
  • Proto-Oncogene Proteins / genetics
  • Proto-Oncogene Proteins / metabolism
  • RNA Interference
  • RNA, Small Interfering
  • SKP Cullin F-Box Protein Ligases / genetics


  • Antigens
  • CDK5RAP2 protein, human
  • CEP68 protein, human
  • Cell Cycle Proteins
  • Intracellular Signaling Peptides and Proteins
  • Microtubule-Associated Proteins
  • Nerve Tissue Proteins
  • Proto-Oncogene Proteins
  • RNA, Small Interfering
  • pericentrin
  • SKP Cullin F-Box Protein Ligases
  • Protein Serine-Threonine Kinases
  • polo-like kinase 1