Transcriptional regulation of the rainbow trout CYP19a gene by FTZ-F1 homologue.
In rainbow trout, there are at least two CYP19 genes (CYP19a and CYP19b). They encode distinct P450arom isozymes that are differentially expressed in the ovary and brain. To understand the transcriptional regulation of the rainbow trout CYP19a (rtCYP19a) gene in the ovary, we isolated its 5'-flanking region. The presence of potential FTZ-F1-binding sites prompted us to isolate the cDNA encoding a rainbow trout FTZ-F1 homologue (rtFTZ-F1) and analyze its effect on the rtCYP19a gene transcriptional activity. RT-PCR analysis showed overlapping expression of the rtCYP19a and rtFTZ-F1 genes in the ovary. Transient transfection studies in Chinese hamster ovary-derived CHO-K1 cells revealed that the region from -247 to -105, which contains three potential FTZ-F1-binding sites, was required for rtFTZ-F1-mediated transcriptional activation of the rtCYP19a gene. Among the three potential binding sites, the two from -150 to -142 and from -118 to -110 showed strong affinities for rtFTZ-F1 in gel shift assays, and base substitutions in either site almost abolished the transcriptional activation by rtFTZ-F1. Taken together, these results demonstrate that rtFTZ-F1 plays an important role in the transcriptional regulation of the rtCYP19a gene in the ovary.
Kanda
Hiromi
H
Department of Biosciences, School of Science, Kitasato University, Sagamihara, Kanagawa 228-8555, Japan.
Okubo
Takayuki
T
Omori
Nobuhiro
N
Niihara
Hiroko
H
Matsumoto
Naoko
N
Yamada
Kayo
K
Yoshimoto
Shin
S
Ito
Michihiko
M
Yamashita
Shinya
S
Shiba
Tadayoshi
T
Takamatsu
Nobuhiko
N
D000595:Amino Acid Sequence; D000818:Animals; D001141:Aromatase / Q000235:genetics*; D001483:Base Sequence; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D024202:Electrophoretic Mobility Shift Assay; D005260:Female; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000235:genetics*; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D017686:Oncorhynchus mykiss / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics* / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D054339:Steroidogenic Factor 1; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014162:Transfection; D029961:Zebrafish Proteins / Q000235:genetics*
D018076:DNA, Complementary; D018398:Homeodomain Proteins; D018160:Receptors, Cytoplasmic and Nuclear; D011993:Recombinant Fusion Proteins; D054339:Steroidogenic Factor 1; D014157:Transcription Factors; D029961:Zebrafish Proteins; D008156:Luciferases; D001141:Aromatase; C440729:Cyp19a1a protein, zebrafish