Actions of two different cAMP-responsive sequences and an enhancer of the human CYP11A1 (P450scc) gene in adrenal Y1 and placental JEG-3 cells.
We have characterized three cis-acting elements of the human CYP11A1 gene. A proximal cAMP-responsive sequence (P-CRS) functioned in both adrenal Y1 and placental JEG-3 cells. An upstream cAMP-responsive sequence (U-CRS) and an enhancer, localized by transfections of deleted gene segments linked to a reporter gene to bases -1621 to -1503 and -1931 to -1822, respectively, functioned in Y1 but not JEG-3 cells. Both regions bind proteins only from Y1 cells as identified by footprinting analysis. U-CRS contains the TCAAGGTCA sequence that binds the nuclear receptor family of proteins. The cAMP-dependent transcription mediated by U-CRS, but not by P-CRS, was abolished in a cell line deficient in cAMP-dependent protein kinase. Therefore, P-CRS and U-CRS use different effectors to mediate cAMP response. Gel mobility shift, competition, and antibody supershift experiments showed that nucleotides -117 to -94, which contributed to P-CRS activity in transfection experiments, bound weakly to Sp1-like proteins. This feature is shared by many proximal regulatory elements of steroidogenic genes. Therefore, steroidogenic genes could be coordinately regulated through common regulatory elements such as P-CRS, U-CRS, and cell type-selective enhancers.
Guo
I C
IC
Institute of Molecular Biology, Academia Sinica, Nankang, Taiwan, Republic of China.
Tsai
H M
HM
Chung
B C
BC
D000311:Adrenal Glands / Q000201:enzymology; D001483:Base Sequence; D001665:Binding Sites; D001667:Binding, Competitive; D002460:Cell Line; D002786:Cholesterol Side-Chain Cleavage Enzyme / Q000096:biosynthesis / Q000235:genetics*; D000242:Cyclic AMP / Q000378:metabolism*; D004247:DNA / Q000302:isolation & purification / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004742:Enhancer Elements, Genetic; D005260:Female; D015870:Gene Expression; D006801:Humans; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D010920:Placenta / Q000201:enzymology; D010957:Plasmids; D011247:Pregnancy; D011401:Promoter Regions, Genetic; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism*; D012045:Regulatory Sequences, Nucleic Acid; D017384:Sequence Deletion; D014158:Transcription, Genetic; D014162:Transfection
D004268:DNA-Binding Proteins; D009838:Oligodeoxyribonucleotides; D018160:Receptors, Cytoplasmic and Nuclear; D004247:DNA; D000242:Cyclic AMP; D002786:Cholesterol Side-Chain Cleavage Enzyme