Apoptosis-stimulating protein of p53-2 (ASPP2/53BP2L) is an E2F target gene

Cell Death Differ. 2005 Apr;12(4):358-68. doi: 10.1038/sj.cdd.4401536.

Abstract

The p53 pathway is a central apoptotic regulator. Deregulation of the Rb/E2F pathway occurs in a majority of tumors, resulting in both unrestrained proliferation and enhanced apoptosis sensitivity via p53-dependent and independent mechanisms. However, the mechanisms coupling the p53 and Rb/E2F pathways remain incompletely understood. We report that ASPP2/53BP2L, a p53/p73-binding protein that promotes p53/p73-dependent apoptosis, is an E2F target gene. The ASPP2/53BP2L promoter was identified and ectopic expression of transcription-competent E2F-1 (E2F-2 and E2F-3) stimulated an ASPP2/53BP2L promoter-luciferase reporter. Mutational analysis of the ASPP2/53BP2L promoter identified E2F-binding sites that cooperate for E2F-1 induction and basal repression of ASPP2/53BP2L. Moreover, endogenous ASPP2/53BP2L levels increased after E2F-1 expression, and E2F-1 bound the endogenous ASPP2/53BP2L promoter after chromatin immunoprecipitation. Typical for an E2F target, ASPP2/53BP2L expression was maximal in early S-phase. Thus, ASPP2/53BP2L is downstream of E2F, suggesting that it functions as a common link between the p53/p73 and Rb/E2F apoptotic pathways.

Publication types

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

MeSH terms

  • Apoptosis / genetics
  • Apoptosis / physiology*
  • Apoptosis Regulatory Proteins
  • Base Sequence
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Cell Cycle Proteins / metabolism*
  • DNA-Binding Proteins / metabolism*
  • E2F Transcription Factors
  • E2F1 Transcription Factor
  • E2F2 Transcription Factor
  • E2F3 Transcription Factor
  • Gene Expression Regulation / physiology
  • Genes, Tumor Suppressor
  • Humans
  • Molecular Sequence Data
  • Nuclear Proteins / metabolism
  • Promoter Regions, Genetic
  • S Phase / physiology
  • Transcription Factors / metabolism*
  • Tumor Protein p73
  • Tumor Suppressor Protein p53 / metabolism
  • Tumor Suppressor Proteins

Substances

  • Apoptosis Regulatory Proteins
  • Carrier Proteins
  • Cell Cycle Proteins
  • DNA-Binding Proteins
  • E2F Transcription Factors
  • E2F1 Transcription Factor
  • E2F1 protein, human
  • E2F2 Transcription Factor
  • E2F2 protein, human
  • E2F3 Transcription Factor
  • Nuclear Proteins
  • TP53BP2 protein, human
  • TP73 protein, human
  • Transcription Factors
  • Tumor Protein p73
  • Tumor Suppressor Protein p53
  • Tumor Suppressor Proteins