Activation and suppression of a cryptic promoter in the intron of the human melanoma-associated ME491 antigen gene.
A deletion mutant of the human melanoma-associated ME491 antigen gene starting at the first intron (lambda R31) differentially mediates the antigen expression depending on the cell type. Cryptic promoter activity residing in a 270-base-pair (bp) fragment of the first intron was examined by primer extension analysis and recombinant chloramphenicol acetyltransferase (CAT) assay. The cryptic promoter, further localized within a 153-bp fragment (fr153BN), exerted its effect in Ltk- and H-ras-transformed NIH3T3 (3T3-Hras) but not in parental NIH3T3 cells. The results suggested that the cryptic promoter was associated with a novel ras-responsive positive regulatory element, since fr153BN did not contain an AP-1-binding sequence motif, known as the ras-responsive enhancer element. The cryptic promoter activity of fr153BN was suppressed by an upstream 121-bp fragment (fr121SB) which contained a consensus sequence motif for binding of a repressor protein, GC factor, and regions showing sequence similarity with putative cis-acting repressor elements found in the vimentin gene. The degree of the suppression was greater in 3T3-Hras than in Ltk- cells. These positive and negative regulatory elements may be differentially involved in the regulation of ME491 antigen expression depending on the cell type.
Takahashi
N
N
Department of Microbiology, Kobe University School of Medicine.
Hotta
H
H
Homma
M
M
D016475:3T3 Cells; D000818:Animals; D015703:Antigens, CD / Q000235:genetics*; D000951:Antigens, Neoplasm / Q000235:genetics*; D001483:Base Sequence; D001665:Binding Sites; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics / Q000378:metabolism; D004742:Enhancer Elements, Genetic; D015972:Gene Expression Regulation, Neoplastic; D011905:Genes, ras; D006801:Humans; D007438:Introns; D008545:Melanoma / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D010980:Platelet Membrane Glycoproteins / Q000235:genetics*; D011401:Promoter Regions, Genetic; D011994:Recombinant Proteins / Q000378:metabolism; D012045:Regulatory Sequences, Nucleic Acid; D012097:Repressor Proteins / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D013489:Suppression, Genetic; D060149:Tetraspanin 30; D014157:Transcription Factors / Q000378:metabolism; D014162:Transfection
D015703:Antigens, CD; D000951:Antigens, Neoplasm; C554586:CD63 protein, human; C554587:Cd63 protein, mouse; D009838:Oligodeoxyribonucleotides; D010980:Platelet Membrane Glycoproteins; D011994:Recombinant Proteins; D012097:Repressor Proteins; D060149:Tetraspanin 30; D014157:Transcription Factors; D015500:Chloramphenicol O-Acetyltransferase