Interaction of an NF-kappa B-like factor with a site upstream of the c-myc promoter.
The c-myc protooncogene has been implicated in control of growth and differentiation of mammalian cells. For instance, growth arrest is often preceded by reduction in c-myc mRNA and gene transcription. To elucidate the mechanisms of control of c-myc gene transcription, we have begun to characterize the interaction of nuclear factors with the 719-base-pair (bp) c-myc regulatory domain, located 1139-421 bp upstream of the P1 start site of the mouse gene. Nuclear extracts from exponentially growing WEHI 231 murine B-lymphoma cells formed multiple complexes in mobility-shift assays. Changes in complex distribution were observed in growth-arrested WEHI 231 cells, and a major site of this interaction mapped to a 21-bp sequence that is similar to the sequences recognized by the NF-kappa B family of proteins. Binding of NF-kappa B-like factors was demonstrated by oligonucleotide competition. Induction of complex formation upon 70Z/3 pre-B- to B-cell differentiation, enhancement of binding by GTP, and detergent-induced release of inhibitor protein suggested that NF-kappa B itself is one member of the family that can bind. Transfection of thymidine kinase-chloramphenicol acetyltransferase constructs containing the 21-bp c-myc sequence into Jurkat cells demonstrated increased chloramphenicol acetyltransferase activity upon phorbol ester and phytohemagglutinin treatment. These results suggest the involvement of NF-kappa B-like factors in the regulation of c-myc transcription.
Department of Biochemistry, Boston University School of Medicine, MA 02118.
M P
MP
Duyao
A J
AJ
Buckler
G E
GE
Sonenshein
D001483:Base Sequence; D001665:Binding Sites; D001667:Binding, Competitive; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D016328:NF-kappa B; D015345:Oligonucleotide Probes / Q000138:chemical synthesis; D010957:Plasmids; D011401:Promoter Regions, Genetic; D011505:Protein-Tyrosine Kinases / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D016271:Proto-Oncogene Proteins c-myc; D011519:Proto-Oncogenes; D014157:Transcription Factors / Q000378:metabolism*; D014162:Transfection
D004268:DNA-Binding Proteins; D016328:NF-kappa B; D015345:Oligonucleotide Probes; D011518:Proto-Oncogene Proteins; D016271:Proto-Oncogene Proteins c-myc; D014157:Transcription Factors; D015500:Chloramphenicol O-Acetyltransferase; D011505:Protein-Tyrosine Kinases