The 65-kDa subunit of human NF-kappa B functions as a potent transcriptional activator and a target for v-Rel-mediated repression.
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.
Ballard
D W
DW
Howard Hughes Medical Institute, Department of Medicine, Duke University Medical Center, Durham, NC 27710.
Dixon
E P
EP
Peffer
N J
NJ
Bogerd
H
H
Doerre
S
S
Stein
B
B
Greene
W C
WC
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004742:Enhancer Elements, Genetic; D005786:Gene Expression Regulation; D006801:Humans; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016328:NF-kappa B / Q000737:chemistry / Q000502:physiology*; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D020572:Oncogene Proteins v-rel; D012097:Repressor Proteins / Q000737:chemistry / Q000502:physiology*; D015682:Retroviridae Proteins, Oncogenic / Q000502:physiology*; D015534:Trans-Activators; D014157:Transcription Factors / Q000737:chemistry / Q000502:physiology*; D014158:Transcription, Genetic
D046911:Macromolecular Substances; D016328:NF-kappa B; D009838:Oligodeoxyribonucleotides; D020572:Oncogene Proteins v-rel; D012097:Repressor Proteins; D015682:Retroviridae Proteins, Oncogenic; D015534:Trans-Activators; D014157:Transcription Factors