title: Isolation and sequence of the promoter region of the human multidrug-resistance (P-glycoprotein) gene.
abstract: Intrinsic and acquired multidrug resistance is an important problem in cancer therapy. Multidrug resistance results from overexpression of the MDR 1 gene, which encodes a drug-efflux pump called P-glycoprotein. We have isolated a 1-kilobase genomic fragment containing the major transcription initiation sites for the human MDR 1 gene. Ribonuclease protection experiments using this fragment indicate that normal human adrenal, colon, and liver cells, the human hepatoma cell line HepG2, and vinblastine-selected human KB multidrug-resistant cells initiate transcription of the MDR 1 gene at the same site within this fragment. The 0.43-kilobase region upstream from the major transcription initiation site linked to the chloramphenicol acetyltransferase gene showed promoter activity in CV-1 monkey kidney cells and in human KB cells. The putative promoter region has a consensus CAAT box and two GC box-like sequences, but no TATA sequence. This identification and isolation of promoter sequences for the MDR 1 gene will permit studies on how expression of this gene is regulated in normal human tissues and cancers.
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000123:Acetyltransferases / Q000378:metabolism; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D015500:Chloramphenicol O-Acetyltransferase; D004262:DNA Restriction Enzymes / Q000378:metabolism; D015252:Deoxyribonucleases, Type II Site-Specific; D004351:Drug Resistance / Q000235:genetics*; D006801:Humans; D008562:Membrane Glycoproteins / Q000235:genetics*; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012260:Ribonucleases / Q000378:metabolism; D014158:Transcription, Genetic; D014162:Transfection; D014407:Tumor Cells, Cultured / Q000032:analysis
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D008562:Membrane Glycoproteins; D000123:Acetyltransferases; D015500:Chloramphenicol O-Acetyltransferase; D012260:Ribonucleases; D004262:DNA Restriction Enzymes; C024388:CTGCAG-specific type II deoxyribonucleases; D015252:Deoxyribonucleases, Type II Site-Specific