title: Target sequences for cis-acting regulation within the dual promoter of the human c-myc gene.
abstract: Recombinant plasmids of the human c-myc promoter-leader region and the bacterial chloramphenicol acetyltransferase (cat) gene were constructed. After transfection into different rodent and human cells, the 862-base-pair (bp) PvuII fragment carrying both c-myc promoters and 350 bp of the untranslated leader conferred 1/15 to 1/30 of the CAT activity mediated by the simian virus 40 promoter. The presence of additional sequences upstream of the PvuII fragment had an overall negative effect on c-myc promoter activity detectable by titration analysis with small amounts of transfected plasmid DNA. The analysis of numerous deletion constructs in the c-myc promoter-leader region as well as S1 mapping experiments demonstrated that the high CAT activity depended largely on the presence of the second promoter. By cotransfection of c-myc-cat constructs with plasmids carrying different parts of the c-myc promoter locus, targets for positively acting cellular factors were identified. Two positive regulatory elements were mapped within the 862-bp PvuII fragment. One was localized within the 248-bp PvuII-SmaI fragment -101 to -349 bp upstream of the first cap site and the other within the 142-pb XhoI-NaeI fragment of the first exon, comprising positions -95 to +47 relative to the second cap site. We conclude that the dual promotor of the human c-myc gene represents a strong eucaryotic promotor regulated by cooperation of positively and negatively acting cellular transcription factors.
mesh_terms: D000123:Acetyltransferases / Q000235:genetics; D000818:Animals; D015500:Chloramphenicol O-Acetyltransferase; D004262:DNA Restriction Enzymes; D005796:Genes; D005809:Genes, Regulator; D006801:Humans; D009693:Nucleic Acid Hybridization; D010957:Plasmids; D011401:Promoter Regions, Genetic; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D011519:Proto-Oncogenes; D014158:Transcription, Genetic
chemical_list: D011518:Proto-Oncogene Proteins; D000123:Acetyltransferases; D015500:Chloramphenicol O-Acetyltransferase; D004262:DNA Restriction Enzymes