title: The mechanisms by which a human apolipoprotein B gene enhancer and reducer interact with the promoter are different in cultured cells of hepatic and intestinal origin.
abstract: In the preceding paper (Paulweber, B., Onasch, M. A., Nagy, B. P., and Levy-Wilson, B. (1991) J. Biol. Chem. 266, 24149-24160) we demonstrated that the segment of the apolipoprotein B promoter extending from -260 to -85 is functionally different in hepatic (HepG2) and intestinal (CaCo-2) cells. These functional differences could be explained at least in part by differences in binding of three nuclear proteins to the region from -111 to -88. In this article we present further evidence suggesting that the mechanisms involved in transcriptional control of the apolipoprotein B gene in HepG2 and CaCo-2 cells are different, by demonstrating that an enhancer and a reducer can alter the activity of various apolipoprotein B promoter segments in widely differing ways in these two cell lines. Furthermore, we have localized a 329-base pair segment that is found within a negative regulatory region in the 5' distal portion of the gene. It displays a strong reducer effect upon promoter sequences that exhibit maximal transcriptional activity in CaCo-2 cells, but not in HepG2 cells.
authors.affiliation: Gladstone Foundation Laboratories for Cardiovascular Disease, University of California, San Francisco 94140-0608.
authors.forename: B
authors.initials: B
authors.lastname: Paulweber
authors.forename: B
authors.initials: B
authors.lastname: Levy-Wilson
mesh_terms: D001055:Apolipoproteins B / Q000235:genetics*; D001483:Base Sequence; D006528:Carcinoma, Hepatocellular; D002460:Cell Line; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics / Q000378:metabolism; D002872:Chromosome Deletion; D003110:Colonic Neoplasms; D004273:DNA, Neoplasm / Q000235:genetics / Q000302:isolation & purification; D003850:Deoxyribonuclease I; D004742:Enhancer Elements, Genetic; D005796:Genes; D006801:Humans; D008113:Liver Neoplasms; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010957:Plasmids; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012045:Regulatory Sequences, Nucleic Acid; D015183:Restriction Mapping; D014162:Transfection
chemical_list: D001055:Apolipoproteins B; D004273:DNA, Neoplasm; D011993:Recombinant Fusion Proteins; D015500:Chloramphenicol O-Acetyltransferase; D003850:Deoxyribonuclease I