A novel promoter controls Cyp19a1 gene expression in mouse adipose tissue

<p>Abstract</p> <p>Background</p> <p>Aromatase, the key enzyme in estrogen biosynthesis, is encoded by the Cyp19a1 gene. Thus far, 3 unique untranslated first exons associated with distinct promoters in the mouse Cyp19a1 gene have been described (brain, ovary, and testi...

Full description

Bibliographic Details
Main Authors: Lin Zhihong, Yilmaz Mehmet B, Reierstad Scott, Brooks David C, Innes Joy, Zhao Hong, Bulun Serdar E
Format: Article
Language:English
Published: BMC 2009-04-01
Series:Reproductive Biology and Endocrinology
Online Access:http://www.rbej.com/content/7/1/37
_version_ 1818233444131405824
author Lin Zhihong
Yilmaz Mehmet B
Reierstad Scott
Brooks David C
Innes Joy
Zhao Hong
Bulun Serdar E
author_facet Lin Zhihong
Yilmaz Mehmet B
Reierstad Scott
Brooks David C
Innes Joy
Zhao Hong
Bulun Serdar E
author_sort Lin Zhihong
collection DOAJ
description <p>Abstract</p> <p>Background</p> <p>Aromatase, the key enzyme in estrogen biosynthesis, is encoded by the Cyp19a1 gene. Thus far, 3 unique untranslated first exons associated with distinct promoters in the mouse Cyp19a1 gene have been described (brain, ovary, and testis-specific). It remains unknown whether aromatase is expressed in other mouse tissues via novel and tissue-specific promoters.</p> <p>Methods</p> <p>Real-time PCR was used to examine the aromatase expression levels in various C57BL/6 mouse tissues. 5'-rapid amplification of cDNA ends (5'-RACE) was used to determine the transcriptional start sites of Cyp19a1 transcripts. Promoter activity was measured using serial deletion mutants of DNA fused to the luciferase reporter gene. Primary mouse adipose fibroblasts were isolated and cultured from 16-week-old mouse gonadal fat pads.</p> <p>Results</p> <p>We systematically analyzed Cyp19a1 expression in a large number of mouse tissues, and demonstrated for the first time that aromatase was expressed in the male but not female gonadal fat pad. Subcutaneous and brown adipose tissue did not contain detectable Cyp19a1 mRNA. We used 5'-RACE to clone a novel gonadal fat-specific untranslated first exon, which is spliced onto a common junction 15 bp upstream of the translation start site. This adipose-specific first exon was mapped to approximately 75 kb upstream of the translation start site. Transfection of luciferase reporter gene plasmids containing the promoter region upstream of the adipose-specific first exon into murine 3T3-L1 adipose fibroblasts demonstrated significant basal promoter activity conferred primarily by the sequence located at -343/-1 bp. Dexamethasone significantly induced activity of this adipose-specific promoter region. Adipose-specific Cyp19a1 mRNA was expressed in primary mouse adipose fibroblasts and significantly induced by dexamethasone alone or serum plus dexamethasone.</p> <p>Conclusion</p> <p>Taken together, this research identified a novel, adipose-specific first exon of Cyp19a1 and its hormonally regulated promoter region in male murine gonadal fat. These results expand the known 5'-regulatory region of the murine Cyp19a1 gene to 75 kb upstream of the translation start site. Cyp19a1 expression in mouse adipose tissue may play an important role in reproductive biology and lipid metabolism.</p>
first_indexed 2024-12-12T11:22:16Z
format Article
id doaj.art-dfbb7ea3c4bb4537986552d289d2880e
institution Directory Open Access Journal
issn 1477-7827
language English
last_indexed 2024-12-12T11:22:16Z
publishDate 2009-04-01
publisher BMC
record_format Article
series Reproductive Biology and Endocrinology
spelling doaj.art-dfbb7ea3c4bb4537986552d289d2880e2022-12-22T00:26:00ZengBMCReproductive Biology and Endocrinology1477-78272009-04-01713710.1186/1477-7827-7-37A novel promoter controls Cyp19a1 gene expression in mouse adipose tissueLin ZhihongYilmaz Mehmet BReierstad ScottBrooks David CInnes JoyZhao HongBulun Serdar E<p>Abstract</p> <p>Background</p> <p>Aromatase, the key enzyme in estrogen biosynthesis, is encoded by the Cyp19a1 gene. Thus far, 3 unique untranslated first exons associated with distinct promoters in the mouse Cyp19a1 gene have been described (brain, ovary, and testis-specific). It remains unknown whether aromatase is expressed in other mouse tissues via novel and tissue-specific promoters.</p> <p>Methods</p> <p>Real-time PCR was used to examine the aromatase expression levels in various C57BL/6 mouse tissues. 5'-rapid amplification of cDNA ends (5'-RACE) was used to determine the transcriptional start sites of Cyp19a1 transcripts. Promoter activity was measured using serial deletion mutants of DNA fused to the luciferase reporter gene. Primary mouse adipose fibroblasts were isolated and cultured from 16-week-old mouse gonadal fat pads.</p> <p>Results</p> <p>We systematically analyzed Cyp19a1 expression in a large number of mouse tissues, and demonstrated for the first time that aromatase was expressed in the male but not female gonadal fat pad. Subcutaneous and brown adipose tissue did not contain detectable Cyp19a1 mRNA. We used 5'-RACE to clone a novel gonadal fat-specific untranslated first exon, which is spliced onto a common junction 15 bp upstream of the translation start site. This adipose-specific first exon was mapped to approximately 75 kb upstream of the translation start site. Transfection of luciferase reporter gene plasmids containing the promoter region upstream of the adipose-specific first exon into murine 3T3-L1 adipose fibroblasts demonstrated significant basal promoter activity conferred primarily by the sequence located at -343/-1 bp. Dexamethasone significantly induced activity of this adipose-specific promoter region. Adipose-specific Cyp19a1 mRNA was expressed in primary mouse adipose fibroblasts and significantly induced by dexamethasone alone or serum plus dexamethasone.</p> <p>Conclusion</p> <p>Taken together, this research identified a novel, adipose-specific first exon of Cyp19a1 and its hormonally regulated promoter region in male murine gonadal fat. These results expand the known 5'-regulatory region of the murine Cyp19a1 gene to 75 kb upstream of the translation start site. Cyp19a1 expression in mouse adipose tissue may play an important role in reproductive biology and lipid metabolism.</p>http://www.rbej.com/content/7/1/37
spellingShingle Lin Zhihong
Yilmaz Mehmet B
Reierstad Scott
Brooks David C
Innes Joy
Zhao Hong
Bulun Serdar E
A novel promoter controls Cyp19a1 gene expression in mouse adipose tissue
Reproductive Biology and Endocrinology
title A novel promoter controls Cyp19a1 gene expression in mouse adipose tissue
title_full A novel promoter controls Cyp19a1 gene expression in mouse adipose tissue
title_fullStr A novel promoter controls Cyp19a1 gene expression in mouse adipose tissue
title_full_unstemmed A novel promoter controls Cyp19a1 gene expression in mouse adipose tissue
title_short A novel promoter controls Cyp19a1 gene expression in mouse adipose tissue
title_sort novel promoter controls cyp19a1 gene expression in mouse adipose tissue
url http://www.rbej.com/content/7/1/37
work_keys_str_mv AT linzhihong anovelpromotercontrolscyp19a1geneexpressioninmouseadiposetissue
AT yilmazmehmetb anovelpromotercontrolscyp19a1geneexpressioninmouseadiposetissue
AT reierstadscott anovelpromotercontrolscyp19a1geneexpressioninmouseadiposetissue
AT brooksdavidc anovelpromotercontrolscyp19a1geneexpressioninmouseadiposetissue
AT innesjoy anovelpromotercontrolscyp19a1geneexpressioninmouseadiposetissue
AT zhaohong anovelpromotercontrolscyp19a1geneexpressioninmouseadiposetissue
AT bulunserdare anovelpromotercontrolscyp19a1geneexpressioninmouseadiposetissue
AT linzhihong novelpromotercontrolscyp19a1geneexpressioninmouseadiposetissue
AT yilmazmehmetb novelpromotercontrolscyp19a1geneexpressioninmouseadiposetissue
AT reierstadscott novelpromotercontrolscyp19a1geneexpressioninmouseadiposetissue
AT brooksdavidc novelpromotercontrolscyp19a1geneexpressioninmouseadiposetissue
AT innesjoy novelpromotercontrolscyp19a1geneexpressioninmouseadiposetissue
AT zhaohong novelpromotercontrolscyp19a1geneexpressioninmouseadiposetissue
AT bulunserdare novelpromotercontrolscyp19a1geneexpressioninmouseadiposetissue