Rb and FZR1/Cdh1 determine CDK4/6-cyclin D requirement in C. elegans and human cancer cells

Nat Commun. 2015 Jan 6;6:5906. doi: 10.1038/ncomms6906.

Abstract

Cyclin-dependent kinases 4 and 6 (CDK4/6) in complex with D-type cyclins promote cell cycle entry. Most human cancers contain overactive CDK4/6-cyclin D, and CDK4/6-specific inhibitors are promising anti-cancer therapeutics. Here, we investigate the critical functions of CDK4/6-cyclin D kinases, starting from an unbiased screen in the nematode Caenorhabditis elegans. We found that simultaneous mutation of lin-35, a retinoblastoma (Rb)-related gene, and fzr-1, an orthologue to the APC/C co-activator Cdh1, completely eliminates the essential requirement of CDK4/6-cyclin D (CDK-4/CYD-1) in C. elegans. CDK-4/CYD-1 phosphorylates specific residues in the LIN-35 Rb spacer domain and FZR-1 amino terminus, resembling inactivating phosphorylations of the human proteins. In human breast cancer cells, simultaneous knockdown of Rb and FZR1 synergistically bypasses cell division arrest induced by the CDK4/6-specific inhibitor PD-0332991. Our data identify FZR1 as a candidate CDK4/6-cyclin D substrate and point to an APC/C(FZR1) activity as an important determinant in response to CDK4/6-inhibitors.

Publication types

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

MeSH terms

  • Animals
  • Base Sequence
  • Caenorhabditis elegans
  • Caenorhabditis elegans Proteins / genetics
  • Cdh1 Proteins / genetics
  • Cdh1 Proteins / metabolism*
  • Cell Cycle / physiology*
  • Cell Line, Tumor
  • Cyclin D / metabolism
  • Cyclin-Dependent Kinase 4 / metabolism
  • Cyclin-Dependent Kinase 6 / metabolism
  • Gene Knockdown Techniques
  • HEK293 Cells
  • Humans
  • Immunoprecipitation
  • Mass Spectrometry
  • Microscopy, Fluorescence
  • Molecular Sequence Data
  • Multiprotein Complexes / metabolism*
  • Repressor Proteins / genetics
  • Retinoblastoma Protein / genetics
  • Retinoblastoma Protein / metabolism*
  • Sequence Analysis, DNA

Substances

  • Caenorhabditis elegans Proteins
  • Cdh1 Proteins
  • Cyclin D
  • FZR1 protein, human
  • Multiprotein Complexes
  • Repressor Proteins
  • Retinoblastoma Protein
  • lin-35 protein, C elegans
  • Cyclin-Dependent Kinase 4
  • Cyclin-Dependent Kinase 6