FEV acts as a transcriptional repressor through its DNA-binding ETS domain and alanine-rich domain

Oncogene. 2003 May 22;22(21):3319-29. doi: 10.1038/sj.onc.1206572.

Abstract

Although most Ets transcription factors have been characterized as transcriptional activators, some of them display repressor activity. Here we characterize an Ets-family member, the very specifically expressed human Fifth Ewing Variant (FEV), as a transcriptional repressor. We show that among a broad range of human cell lines, only Dami megakaryocytic cells express FEV. This nuclear protein binds to Ets-binding sites, such as that of the human ICAM-1 promoter. We used this promoter to demonstrate that FEV can repress both basal transcription and, even more strongly, ectopically Ets-activated transcription. We identified two domains responsible for FEV-mediated repression: the ETS domain, responsible for passive repression, and the carboxy-terminal alanine-rich domain, involved in active repression. In the Ets-independent LEXA system also, FEV acts as a transcriptional repressor via its alanine-rich carboxy-terminal domain. The mechanism by which FEV actively represses transcription is currently unknown, since FEV-triggered repression is not reversed by the histone deacetylase inhibitor trichostatin A. We also showed that long-term overexpression of FEV proteins containing the alanine-rich domain prevents cell clones from growing, whereas clones expressing a truncated FEV protein lacking this domain develop like control cells. This confirms the importance of this domain in FEV-triggered repression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alanine / analysis*
  • Animals
  • COS Cells
  • Cell Line
  • Cell Nucleus / chemistry
  • DNA-Binding Proteins / chemistry*
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / physiology*
  • Gene Silencing*
  • Humans
  • Nuclear Proteins / chemistry*
  • Nuclear Proteins / genetics
  • Nuclear Proteins / physiology*
  • Protein Structure, Tertiary
  • Proto-Oncogene Proteins / antagonists & inhibitors
  • Proto-Oncogene Proteins / chemistry
  • Proto-Oncogene Proteins / metabolism
  • Proto-Oncogene Proteins c-ets
  • Rabbits
  • Repressor Proteins / chemistry*
  • Repressor Proteins / physiology*
  • Response Elements
  • Transcription Factors / antagonists & inhibitors
  • Transcription Factors / chemistry
  • Transcription Factors / metabolism
  • Transcription, Genetic
  • Transfection
  • Tumor Cells, Cultured

Substances

  • DNA-Binding Proteins
  • FEV protein, human
  • Nuclear Proteins
  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-ets
  • Repressor Proteins
  • Transcription Factors
  • Alanine