title: Stringent regulation of stably integrated chloramphenicol acetyl transferase genes by E. coli lac repressor in monkey cells.
abstract: Monkey cell lines that constitutively synthesize 38.6 kd lac repressor protein and bear stably integrated chloramphenicol acetyl transferase (CAT) genes linked to a lac operator-containing SV40 early promoter-enhancer were generated. When grown in medium containing isopropyl beta-D-thiogalactoside (IPTG), these cells acquired a CAT+ phenotype. In contrast, when grown in parallel in medium lacking IPTG, the cells remained CAT-. Maximum induction of CAT activity occurred after 4 days of IPTG exposure. Three days after removal of IPTG, induced cells had reverted to CAT-. Specific CAT activity increased up to 60-fold after induction, while background activity in uninduced cells was similar to or only slightly above that of parental, CAT- cells. CAT activity increased stepwise over a wide range of IPTG concentrations. Thus lac repressor-operator complexes can form on primate chromosomes and stringently block transcription from an adjoining promoter.
authors.affiliation: Division of Neoplastic Disease Mechanisms, Dana-Farber Cancer Institute, Boston, Massachusetts 02115.
authors.forename: J
authors.initials: J
authors.lastname: Figge
authors.forename: C
authors.initials: C
authors.lastname: Wright
authors.forename: C J
authors.initials: CJ
authors.lastname: Collins
authors.forename: T M
authors.initials: TM
authors.lastname: Roberts
authors.forename: D M
authors.initials: DM
authors.lastname: Livingston
mesh_terms: D000123:Acetyltransferases / Q000235:genetics*; D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D015500:Chloramphenicol O-Acetyltransferase; D004247:DNA / Q000235:genetics; D004262:DNA Restriction Enzymes; D004274:DNA, Recombinant; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D005786:Gene Expression Regulation / Q000187:drug effects; D000882:Haplorhini; D007118:Immunoassay; D007544:Isopropyl Thiogalactoside / Q000494:pharmacology; D007700:Kinetics; D008970:Molecular Weight; D010641:Phenotype; D010957:Plasmids; D011401:Promoter Regions, Genetic; D012097:Repressor Proteins / Q000235:genetics*; D013539:Simian virus 40 / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics*; D014162:Transfection
chemical_list: D004274:DNA, Recombinant; D012097:Repressor Proteins; D014157:Transcription Factors; D007544:Isopropyl Thiogalactoside; D004247:DNA; D000123:Acetyltransferases; D015500:Chloramphenicol O-Acetyltransferase; D004262:DNA Restriction Enzymes