小鼠ob基因启动子中葡萄糖和胰岛素反应元件的鉴定

为了解葡萄糖和胰岛素调控小鼠ob基因表达调控的机制,应用荧光素酶报告基因、凝胶迁移率变动分析（ｇｅｌ ｍｏｂｉｌｉｔｙ ｓｈｉｆｔ ａｓｓａｙｓ,ＧＭＳＡ）、ＤＮａｓｅ Ｉ足迹分析和突变分析技术对小鼠ｏｂ基因启动子－１７１９～－１４５２ｂｐ之间存在负调控元件、ＧＬＲＥ和ＩＲＥ。ＧＭＳＡ结果显示葡萄糖和胰岛素抑制转录因子与顺式元件。ＤＮａｓｅ Ｉ足迹分析和突变分析显示此结合区这ＡＧＣＡＡＡＡ,位于ｏｂ     

Identification and Characterization of a Bidirectional Promoter from the Intergenic Region between the Human DDX13 and RD Genes

The human DDX13 gene encodes a putative RNA helicase of the DExH-box family. In an earlier report we showed that the human DDX13 and RD genes were arranged head-to-head in the class III MHC complex and their ATG start codons were separated by 745 base pairs. We have now analyzed the common 745 bp intergenic region in detail and characterized their promoters. Northern blot analysis revealed that DDX13 and RD exhibit distinct patterns of steady-state expression among multiple human tissues. The promoter regions for DDX13 and RD genes were identified by deletion analysis from 740 bp to 176 bp of the intergenic region fused to a chloramphenicol acetyltransferase (CAT) reporter gene using transient transfection assays. Results indicated that a promoter sequence as small as 176 bp is sufficient for basal expression of both genes in HeLa and HepG2 cells. Functional analysis using a bidirectional reporter system demonstrates that the sequence 262 bp proximal to the DDX13 gene is sufficient for concurrent expression in both directions. However, the common 740 bp intergenic region showed promoter activity in DDX13 only, suggesting the presence of a negatively acting region for the RD gene within the region -267 to -744. It appears that RD expression is controlled by a complex system of positively and negatively acting elements present on distant portions of both genes.