DPY30 regulates pathways in cellular senescence through ID protein expression

EMBO J. 2013 Aug 14;32(16):2217-30. doi: 10.1038/emboj.2013.159. Epub 2013 Jul 19.

Abstract

Cellular senescence is an intrinsic defense mechanism to various cellular stresses: while still metabolically active, senescent cells stop dividing and enter a proliferation arrest. Here, we identify DPY30, a member of all mammalian histone H3K4 histone methyltransferases (HMTases), as a key regulator of the proliferation potential of human primary cells. Following depletion of DPY30, cells show a severe proliferation defect and display a senescent phenotype, including a flattened and enlarged morphology, elevated level of reactive oxygen species (ROS), increased SA-β-galactosidase activity, and formation of senescence-associated heterochromatin foci (SAHFs). While DPY30 depletion leads to a reduced level of H3K4me3-marked active chromatin, we observed a concomitant activation of CDK inhibitors, including p16INK4a, independent of H3K4me3. ChIP experiments show that key regulators of cell-cycle progression, including ID proteins, are under direct control of DPY30. Because ID proteins are negative regulators of the transcription factors ETS1/2, depletion of DPY30 leads to the transcriptional activation of p16INK4a by ETS1/2 and thus to a senescent-like phenotype. Ectoptic re-introduction of ID protein expression can partially rescue the senescence-like phenotype induced by DPY30 depletion. Thus, our data indicate that DPY30 controls proliferation by regulating ID proteins expression, which in turn lead to senescence bypass.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blotting, Western
  • Cellular Senescence / physiology*
  • Chromatin Immunoprecipitation
  • Colony-Forming Units Assay
  • Flow Cytometry
  • Fluorescent Antibody Technique
  • Gene Expression Regulation / physiology*
  • Gene Knockdown Techniques
  • Humans
  • Inhibitor of Differentiation Protein 1 / metabolism*
  • Microarray Analysis
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • RNA Interference
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction / physiology*
  • Transcription Factors
  • beta-Galactosidase

Substances

  • DPY30 protein, human
  • ID1 protein, human
  • Inhibitor of Differentiation Protein 1
  • Nuclear Proteins
  • Transcription Factors
  • beta-Galactosidase