Specificity protein-1 and -3 trans-activate the ovine placental lactogen gene promoter.
Specificity protein-1 and -3 trans-activate the ovine placental lactogen gene promoter.
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特异性蛋白-1 和-3 反式激活绵羊胎盘催乳素基因启动子。
DOI：
10.1016/j.mce.2009.04.006
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发表时间：
2009
影响因子：
4.1
通讯作者：
Anthony,RV
中科院分区：
文献类型：
--
作者：
Jeckel,KM;Limesand,SW;Anthony,RV
绵羊胎盘催乳素（oPL）基因的近端启动子（−383/+16）在体外提供滋养层特异性表达。Footprint 6（FP6; −319/−349）位于该区域内，将FP 6上的两个碱基对突变转染到BeWo细胞中，确定了CCAAT增强子结合蛋白（CEBP）和特异性蛋白（Sp）的潜在结合位点。转染CEBP显性阴性或过表达构建体不影响近端启动子的反式激活。然而，Sp1和Sp3过表达构建体增加（p≤0.05）反式激活。此外，Sp1和Sp3短发夹RNA构建体降低了（p≤0.01）近端启动子的反式激活。在EMSA超位移测定中，Sp1和Sp3抗体能够抑制与BeWo细胞和绵羊绒毛膜双核细胞（oBNC）的核提取物形成的复合物的迁移。此外，对oBNC核提取物的Southwestern分析鉴定了与Sp3对应的核蛋白，其通过Western分析鉴定。综上所述，这些结果表明Sp1和Sp3能够与oPL基因近端启动子的FP 6相互作用，并起增强其反式激活的作用。
The proximal promoter (−383/+16) of the ovine placental lactogen (oPL) gene provides trophoblast-specific expression in vitro. Footprint 6 (FP6; −319/−349) lies within this region, and transfection of two-base pair mutations across FP6 into BeWo cells identified potential binding sites for CCAAT-enhancer binding protein (CEBP) and specificity proteins (Sp). Transfection of CEBP dominant negative or over-expression constructs did not impact transactivation of the proximal promoter. However, Sp1 and Sp3 over-expression constructs increased (p≤0.05) transactivation. Additionally, Sp1 and Sp3 short-hairpin RNA constructs reduced (p≤0.01) transactivation of the proximal promoter. In EMSA supershift assays, Sp1 and Sp3 antibodies were able to inhibit migration of the complexes formed with nuclear extracts from BeWo cells and ovine chorionic binucleate cells (oBNC). Furthermore, Southwestern analysis of oBNC nuclear extracts identified a nuclear protein corresponding with Sp3, identified by Western analysis. In conclusion, these results indicate that Sp1 and Sp3 are capable of interacting with FP6 of the oPL gene proximal promoter and function to enhance its transactivation.