title: The candidate oncoprotein Bcl-3 is an antagonist of p50/NF-kappa B-mediated inhibition.
abstract: The candidate oncogene bcl-3 was discovered as a translocation into the immunoglobulin alpha-locus in some cases of B-cell chronic lymphocytic leukaemias. The protein Bcl-3 contains seven so-called ankyrin repeats. Similar repeat motifs are found in a number of diverse regulatory proteins but the motifs of Bcl-3 are most closely related to those found in I kappa B proteins in which the ankyrin repeat domain is thought to be directly involved in inhibition of NF-kappa B activity. No biological function has yet been described for Bcl-3, but it was noted recently that Bcl-3 interferes with DNA-binding of the p50 subunit of NF-kappa B in vitro. Here we demonstrate that Bcl-3 can aid kappa B site-dependent transcription in vivo by counteracting the inhibitory effects of p50/NF-kappa B homodimers. Bcl-3 may therefore aid activation of select NF-kappa B-regulated genes, including those of the human immunodeficiency virus.
authors.affiliation: Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892.
authors.forename: G
authors.initials: G
authors.lastname: Franzoso
authors.forename: V
authors.initials: V
authors.lastname: Bours
authors.forename: S
authors.initials: S
authors.lastname: Park
authors.forename: M
authors.initials: M
authors.lastname: Tomita-Yamaguchi
authors.forename: K
authors.initials: K
authors.lastname: Kelly
authors.forename: U
authors.initials: U
authors.lastname: Siebenlist
mesh_terms: D000818:Animals; D017487:Ankyrins / Q000235:genetics; D000081242:B-Cell Lymphoma 3 Protein; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D006678:HIV / Q000235:genetics; D016325:HIV Long Terminal Repeat; D006801:Humans; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid; D013601:T-Lymphocytes / Q000378:metabolism; D014157:Transcription Factors; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D017487:Ankyrins; D000081242:B-Cell Lymphoma 3 Protein; C000631344:BCL3 protein, human; D016328:NF-kappa B; D011518:Proto-Oncogene Proteins; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha; D015500:Chloramphenicol O-Acetyltransferase; D005982:Glutathione Transferase