Porcine glucocorticoid receptor (NR3C1) gene: Tissue-specificity of transcriptional strength and glucocorticoid responsiveness of alternative promoters

详细信息    查看全文

• 作者：Zheng Jiang^a ; Lu Qian^b ; Huafeng Zou^a ; Yimin Jia^a ; Yingdong Ni^a ; Xiaojing Yang^a ; Zhihua Jiang^c ; Ruqian Zhao^a ; ^{zhao.ruqian@gmail.com" class="auth_mail}
• 关键词：AP-1 ; Activator protein-1 ; 5&prime ; UTR ; 5&prime ; untranslated region ; Cell Counting Kit-8 ; CCK-8 ; ChIP ; chromatin immunoprecipitation ; CREB ; cAMP response element binding protein ; DEX ; dexamethasone ; EOH ; ethanol ; GCs ; glucocorticoids ; GR ; glucocorticoid receptor ; HPA axis ; hypothalamic&ndash ; pituitary&ndash ; adrenal axis ; nGRE ; negative glucocorticoid response element ; NR3C1 ; nuclear receptor subfamily 3 ; group C ; member 1 ; RU-486 ; mifepristone ; SP1 ; specificity protein 1 ; YY1 ; Yin Yang 1 ; TSS ; t
• 刊名：The Journal of Steroid Biochemistry and Molecular Biology
• 出版年：May, 2014
• 年：2014
• 卷：141
• 期：Complete
• 页码：87-93
• 全文大小：1322 K

文摘

Glucocorticoid receptor (GR) is transcribed in a tissue- and cell-specific manner with multiple exon 1 mRNA variants driven by selective promoters. We recently cloned and characterized the 5.3 kb proximal promoter sequence of porcine GR gene containing 7 untranslated alternative first exons each processed by a distinct promoter. In this study, we showed tissue-specific expression of total GR and its exon 1 mRNA variants in hippocampus, muscle and liver of pigs. Total GR mRNA was most abundant in liver, followed by muscle and hippocampus in descending order. Among all the GR exon 1 mRNA variants detected, GR exon 1-9/10 and 1-4 were the most predominant variants in all the three tissues. The abundance of GR exon 1-4 mRNA was similar to that of 1-10 in muscle, but was significantly lower than 1-10 in liver and hippocampus. The activities of truncated short (S) and long (L) promoters of respective GR exon 1 mRNA variants were analyzed by luciferase reporter assay in 3 representative cell lines, SY5Y, C2C12 and HepG2. S1-10 and S1-4 demonstrated significantly higher activities than other short promoters in all the cell lines examined. Nevertheless, the strongest activity and cell specificity were detected for L1-10 promoter, which was consistent with the predominant exon 1-9/10 expression in porcine tissues. Moreover, with 3 potential nGRE binding sites, L1-10 promoter was more sensitive to dexamethasone (DEX) in HepG2. Our data provide basic knowledge of the transcriptional mechanism underlying the tissue- and cell-specific expression of porcine GR under basal or ligand-stimulated conditions.