I-Rel: a novel rel-related protein that inhibits NF-kappa B transcriptional activity

Genes Dev. 1992 May;6(5):745-60. doi: 10.1101/gad.6.5.745.

Abstract

The NF-kappa B transcription factor complex is comprised of two subunits, p50 and p65, that share significant homology to the rel oncogene. We have isolated a cDNA encoding a novel 66-kD rel-related protein, designated I-Rel. Unlike other rel-related proteins, I-Rel does not interact with DNA. I-Rel forms heterodimers with p50, however, and greatly attenuates its DNA-binding activity--an effect probably resulting from the presence of a domain inhibitory to DNA binding present within the 121 amino-terminal residues of I-Rel. In contrast, I-Rel does not associate with p65. Transfection experiments demonstrate that I-Rel suppresses NF-kappa B-induced transcription, probably through its association with p50. Expression of I-Rel mRNA is induced by mitogenic stimulation and accumulates after the appearance of p50 transcripts. Our findings suggest that p50 and I-Rel are components of a feedback pathway where expression of I-Rel may modulate indirectly the expression of genes responsive to the NF-kappa B transcription factor complex.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Blotting, Northern
  • DNA / metabolism
  • Escherichia coli / genetics
  • Gene Expression Regulation / genetics*
  • Molecular Sequence Data
  • NF-kappa B / genetics*
  • Oncogene Proteins v-rel
  • Phosphoproteins / chemistry
  • Phosphoproteins / genetics*
  • Phosphoproteins / metabolism
  • Precipitin Tests
  • Protein-Tyrosine Kinases / chemistry
  • Protein-Tyrosine Kinases / genetics*
  • Protein-Tyrosine Kinases / metabolism
  • Proto-Oncogene Proteins / chemistry
  • Proto-Oncogene Proteins / genetics*
  • Retroviridae Proteins, Oncogenic / chemistry
  • Retroviridae Proteins, Oncogenic / genetics*
  • Retroviridae Proteins, Oncogenic / metabolism
  • T-Lymphocytes
  • Transcription Factor RelB
  • Transcription Factors*
  • Transcription, Genetic / genetics

Substances

  • NF-kappa B
  • Oncogene Proteins v-rel
  • Phosphoproteins
  • Proto-Oncogene Proteins
  • Retroviridae Proteins, Oncogenic
  • Transcription Factors
  • Transcription Factor RelB
  • DNA
  • Protein-Tyrosine Kinases

Associated data

  • GENBANK/M79310
  • GENBANK/M81118
  • GENBANK/M82885
  • GENBANK/M82886
  • GENBANK/M82887
  • GENBANK/M83221
  • GENBANK/S49473
  • GENBANK/S49475
  • GENBANK/X65112
  • GENBANK/X65113