title: The inducible lac operator-repressor system is functional in mammalian cells.
abstract: We have investigated the use of the Escherichia coli lac operator-repressor system to regulate expression of transfected genes in mammalian cells. We show that lac repressor produced in mouse L cells by transfection of a lacl expression vector blocks transcription of an MSV-CAT fusion gene when the lac operator is inserted at any one of the following sites within the promoter region: between the initiation codon (ATG) and the transcription start site; between the transcription start and TATA box regions; or upstream of the TATA box region. This last result suggests that the repressor may prevent protein-protein interactions involved in transcription activation. The inducer IPTG causes a marked derepression of CAT expression. The lac repressor-operator complex may be useful as an on/off "switch" in the regulation of gene expression for gene transfer experiments.
mesh_terms: D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002467:Cell Nucleus / Q000032:analysis; D003593:Cytoplasm / Q000032:analysis; D004262:DNA Restriction Enzymes / Q000378:metabolism; D004278:DNA, Superhelical; D004926:Escherichia coli / Q000235:genetics; D005786:Gene Expression Regulation; D007763:Lac Operon; D051379:Mice; D012097:Repressor Proteins / Q000096:biosynthesis*; D014157:Transcription Factors / Q000096:biosynthesis*; D014158:Transcription, Genetic; D014162:Transfection
chemical_list: D004278:DNA, Superhelical; D012097:Repressor Proteins; D014157:Transcription Factors; D004262:DNA Restriction Enzymes