Inhibition of transcription factors belonging to the rel/NF-kappa B family by a transdominant negative mutant

EMBO J. 1991 Jul;10(7):1827-32.


The KBF1 factor, which binds to the enhancer A located in the promoter of the mouse MHC class I gene H-2Kb, is indistinguishable from the p50 DNA binding subunit of the transcription factor NF-kappa B, which regulates a series of genes involved in immune and inflammatory responses. The KBF1/p50 factor binds as a homodimer but can also form heterodimers with the products of other members of the same family, like the c-rel and v-rel (proto)oncogenes. The dimerization domain of KBF1/p50 is contained between amino acids 201 and 367. A mutant of KBF1/p50 (delta SP), unable to bind to DNA but able to form homo- or heterodimers, has been constructed. This protein reduces or abolishes in vitro the DNA binding activity of wild-type proteins of the same family (KBF1/p50, c- and v-rel). This mutant also functions in vivo as a trans-acting dominant negative regulator: the transcriptional inducibility of the HIV long terminal repeat (which contains two potential NF-kappa B binding sites) by phorbol ester (PMA) is inhibited when it is co-transfected into CD4+ T cells with the delta SP mutant. Similarly the basal as well as TNF or IL1-induced activity of the MHC class I H-2Kb promoter can be inhibited by this mutant in two different cell lines. These results constitute the first formal demonstration that these genes are regulated by members of the rel/NF-kappa B family.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • CD4-Positive T-Lymphocytes / drug effects
  • CD4-Positive T-Lymphocytes / metabolism
  • Cell Line
  • Chromosome Deletion
  • Enhancer Elements, Genetic
  • Genes, Dominant
  • HIV Long Terminal Repeat
  • Humans
  • Mice
  • Molecular Sequence Data
  • Mutation*
  • NF-kappa B / antagonists & inhibitors*
  • NF-kappa B / genetics
  • NF-kappa B p50 Subunit
  • Oncogene Proteins v-rel
  • Phorbol Esters / pharmacology
  • Retroviridae Proteins, Oncogenic / genetics*
  • Transcription Factors / genetics*
  • Transfection


  • NF-kappa B
  • NF-kappa B p50 Subunit
  • NFKB1 protein, human
  • Oncogene Proteins v-rel
  • Phorbol Esters
  • Retroviridae Proteins, Oncogenic
  • Transcription Factors