cis-acting sequences required for inducible interleukin-2 enhancer function bind a novel Ets-related protein, Elf-1

Mol Cell Biol. 1992 Mar;12(3):1043-53. doi: 10.1128/mcb.12.3.1043-1053.1992.

Abstract

The recent definition of a consensus DNA binding sequence for the Ets family of transcription factors has allowed the identification of potential Ets binding sites in the promoters and enhancers of many inducible T-cell genes. In the studies described in this report, we have identified two potential Ets binding sites, EBS1 and EBS2, which are conserved in both the human and murine interleukin-2 enhancers. Within the human enhancer, these two sites are located within the previously defined DNase I footprints, NFAT-1 and NFIL-2B, respectively. Electrophoretic mobility shift and methylation interference analyses demonstrated that EBS1 and EBS2 are essential for the formation of the NFAT-1 and NFIL-2B nuclear protein complexes. Furthermore, in vitro mutagenesis experiments demonstrated that inducible interleukin-2 enhancer function requires the presence of either EBS1 or EBS2. Two well-characterized Ets family members, Ets-1 and Ets-2, are reciprocally expressed during T-cell activation. Surprisingly, however, neither of these proteins bound in vitro to EBS1 or EBS2. We therefore screened a T-cell cDNA library under low-stringency conditions with a probe from the DNA binding domain of Ets-1 and isolated a novel Ets family member, Elf-1. Elf-1 contains a DNA binding domain that is nearly identical to that of E74, the ecdysone-inducible Drosophila transcription factor required for metamorphosis (hence the name Elf-1, for E74-like factor 1). Elf-1 bound specifically to both EBS1 and EBS2 in electrophoretic mobility shift assays. It also bound to the purine-rich CD3R element from the human immunodeficiency virus type 2 long terminal repeat, which is required for inducible virus expression in response to signalling through the T-cell receptor. Taken together, these results demonstrate that multiple Ets family members with apparently distinct DNA binding specificities regulate differential gene expression in resting and activated T cells.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Amino Acid Sequence
  • Base Sequence
  • Binding Sites
  • Cell Line
  • Cells, Cultured
  • DNA / metabolism
  • DNA-Binding Proteins / metabolism*
  • Electrophoresis, Polyacrylamide Gel
  • Enhancer Elements, Genetic*
  • Humans
  • Interleukin-2 / genetics*
  • Methylation
  • Molecular Sequence Data
  • Proto-Oncogene Protein c-ets-1
  • Proto-Oncogene Proteins / metabolism*
  • Proto-Oncogene Proteins c-ets
  • T-Lymphocytes / metabolism
  • Transcription Factors / metabolism*

Substances

  • DNA-Binding Proteins
  • ETS1 protein, human
  • Interleukin-2
  • Proto-Oncogene Protein c-ets-1
  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-ets
  • Transcription Factors
  • DNA

Associated data

  • GENBANK/M82882