FBXL2 is a ubiquitin E3 ligase subunit that triggers mitotic arrest

Cell Cycle. 2011 Oct 15;10(20):3487-94. doi: 10.4161/cc.10.20.17742. Epub 2011 Oct 15.

Abstract

Mitotic progression is regulated by ubiquitin E3 ligase complexes to carefully orchestrate eukaryotic cell division. Here, we show that a relatively new E3 ligase component belonging to the SCF (Skip-Cullin1-F-box protein) E3 ligase family, SCF (FBXL2) , impairs cell proliferation by mediating cyclin D3 polyubiquitination and degradation. Both cyclin D3 and FBXL2 colocalize within the centrosome. FBXL2 overexpression led to G 2/M-phase arrest in transformed epithelia, resulting in the appearance of supernumerary centrosomes, tetraploidy and nuclei where condensed chromosomes are arranged on circular monopolar spindles typical of mitotic arrest. RNAi-mediated knockdown of cyclin D3 recapitulated effects of SCF (FBXL2) expression. SCF (FBXL2) impaired the ability of cyclin D3 to associate with centrosomal assembly proteins [Aurora A, polo-like kinase 4 (Plk4), CDK11]. Thus, these results suggest a role for SCF (FBXL2) in regulating the fidelity of cellular division.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Analysis of Variance
  • Animals
  • Cell Cycle Checkpoints / physiology*
  • Cell Line
  • Cyclin D3 / genetics
  • Cyclin D3 / metabolism*
  • F-Box Proteins / metabolism*
  • Fluorescence
  • Immunoblotting
  • Immunoprecipitation
  • Mice
  • Mitosis / physiology*
  • Models, Biological*
  • RNA Interference
  • Time Factors
  • Ubiquitin-Protein Ligases / metabolism*
  • Ubiquitination

Substances

  • Cyclin D3
  • F-Box Proteins
  • FBXL2 protein, mouse
  • Ubiquitin-Protein Ligases