An inhibitory carboxyl-terminal domain in Ets-1 and Ets-2 mediates differential binding of ETS family factors to promoter sequences of the mb-1 gene

Proc Natl Acad Sci U S A. 1992 Oct 1;89(19):8889-93. doi: 10.1073/pnas.89.19.8889.

Abstract

The mb-1 gene is expressed only during the early stages of B-lymphocyte differentiation. Here we show that the mb-1 proximal promoter region contains a functionally important binding site for members of the ETS family of DNA-binding proteins. We found that both the E26 virus-encoded v-ets and the myeloid/B-cell-specific factor PU.1 bind efficiently to this site in vitro. By contrast, Ets-1, the lymphocyte-specific cellular homologue of v-ets, and the related, more ubiquitously expressed Ets-2 protein interacted weakly with this binding site. DNA binding by both Ets-1 and Ets-2, however, could be increased 20- to 50-fold by deleting as few as 16 carboxyl-terminal amino acids. The inhibitory carboxyl-terminal amino acid sequence is highly conserved between Ets-1 and Ets-2 but is not present in either v-ets or PU.1. Replacement of the carboxyl-terminal amino acids of v-ets with those of Ets-1 decreased DNA binding by v-ets drastically. Cotranslation of Ets-1 transcripts encoding proteins of different lengths suggested that Ets-1 binds DNA as a monomer. Therefore, the carboxyl-terminal inhibitory domain appears to interfere directly with DNA binding and not with homodimerization. Finally, the functional relevance of ETS factor binding to the mb-1 promoter site was evidenced by the stimulation of transcription through this site by a v-myb-v-ets fusion protein. Together, these data suggest that one or more ETS family factors are involved in the regulation of mb-1 gene expression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • B-Lymphocytes / cytology
  • B-Lymphocytes / physiology
  • Base Sequence
  • Binding Sites
  • Cell Differentiation / genetics
  • Chloramphenicol O-Acetyltransferase / genetics
  • Chloramphenicol O-Acetyltransferase / isolation & purification
  • Chloramphenicol O-Acetyltransferase / metabolism
  • DNA-Binding Proteins / metabolism
  • Gene Expression
  • Molecular Sequence Data
  • Multigene Family
  • Mutagenesis, Site-Directed
  • Oligodeoxyribonucleotides
  • Oncogenes
  • Promoter Regions, Genetic*
  • Protein Biosynthesis
  • Protein-Tyrosine Kinases / genetics
  • Protein-Tyrosine Kinases / metabolism
  • Proto-Oncogene Protein c-ets-1
  • Proto-Oncogene Protein c-ets-2
  • Proto-Oncogene Proteins / genetics
  • Proto-Oncogene Proteins / isolation & purification
  • Proto-Oncogene Proteins / metabolism*
  • Proto-Oncogene Proteins c-ets
  • Proto-Oncogenes
  • Recombinant Fusion Proteins / isolation & purification
  • Recombinant Fusion Proteins / metabolism
  • Repressor Proteins*
  • Restriction Mapping
  • Retroviridae Proteins, Oncogenic / genetics
  • Retroviridae Proteins, Oncogenic / isolation & purification
  • Retroviridae Proteins, Oncogenic / metabolism*
  • Trans-Activators*
  • Transcription Factors*
  • Transcription, Genetic

Substances

  • DNA-Binding Proteins
  • ERF protein, human
  • ETS1 protein, human
  • Oligodeoxyribonucleotides
  • Proto-Oncogene Protein c-ets-1
  • Proto-Oncogene Protein c-ets-2
  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-ets
  • Recombinant Fusion Proteins
  • Repressor Proteins
  • Retroviridae Proteins, Oncogenic
  • Trans-Activators
  • Transcription Factors
  • oncogene proteins v-ets
  • Chloramphenicol O-Acetyltransferase
  • Protein-Tyrosine Kinases