The 65-kDa subunit of human NF-kappa B functions as a potent transcriptional activator and a target for v-Rel-mediated repression

Proc Natl Acad Sci U S A. 1992 Mar 1;89(5):1875-9. doi: 10.1073/pnas.89.5.1875.


Molecular cloning of the polypeptide component of the Rel-related human p75 nucleoprotein complex has revealed its identity with the 65-kDa (p65) subunit of NF-kappa B. Functional analyses of chimeric proteins composed of NF-kappa B p65 C-terminal sequences linked to the DNA-binding domain of the yeast GAL4 polypeptide have indicated that the final 101 amino acids of NF-kappa B p65 comprise a potent transcriptional activation domain. Transient transfection of human T cells with an expression vector encoding NF-kappa B p65, but not NF-kappa B p50, produced marked transcriptional activation of a basal promoter containing duplicated kappa B enhancer motifs from the long terminal repeat of type 1 human immunodeficiency virus. These stimulatory effects of NF-kappa B p65 were synergistically enhanced by coexpression of NF-kappa B p50 but were completely inhibited by coexpression of the v-rel oncogene product. Together, these functional studies demonstrate that NF-kappa B p65 is a transactivating subunit of the heterodimeric NF-kappa B complex and serves as one cellular target for v-Rel-mediated transcriptional repression.

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Cloning, Molecular
  • Enhancer Elements, Genetic
  • Gene Expression Regulation
  • Humans
  • Macromolecular Substances
  • Molecular Sequence Data
  • Molecular Weight
  • NF-kappa B / chemistry
  • NF-kappa B / physiology*
  • Oligodeoxyribonucleotides / chemistry
  • Oncogene Proteins v-rel
  • Repressor Proteins / chemistry
  • Repressor Proteins / physiology*
  • Retroviridae Proteins, Oncogenic / physiology*
  • Trans-Activators
  • Transcription Factors / chemistry
  • Transcription Factors / physiology*
  • Transcription, Genetic


  • Macromolecular Substances
  • NF-kappa B
  • Oligodeoxyribonucleotides
  • Oncogene Proteins v-rel
  • Repressor Proteins
  • Retroviridae Proteins, Oncogenic
  • Trans-Activators
  • Transcription Factors