Candidate cis-elements for human renin gene expression in the promoter region

The regulation of renin gene expression, the rate‐limiting enzyme of the system, is thought to be fundamental to the total system. Previously, we mapped six putative cis‐elements in the promoter region of the human renin gene with nuclear proteins from human chorionic cells and human renal cortex by DNase I protection assay (footprint A–F). Each footprint contains Ets motif like site (A), HOXñPBX recognition sequence (B), unknown sequence as DNA binding consensus (C), CRE (D), COUP‐TFII (ARP‐1) motif like site (E), and AGE3 like site (F). Footprint D has been characterized by means of functional studies as the genuine human renin gene CRE interacting with CREB in cooperation with the site of footprint B. To obtain further clues to the specific expression in the promoter region, these putative cis‐elements were conducted to a consensus‐specific binding assay to compare renin‐producing and non‐renin‐producing cells by EMSA and electromobility super‐shift assay. Different sequence‐specific DNA/protein binding was obtained among the different cell lines with footprint B site, with COUP‐TFII (ARP‐1) motif like site and possibly with footprint F site. The results implicate these putative cis‐elements and each corresponding trans‐factor in the specific expression of the human renin gene in the promoter region. Further functional characterization of these elements would provide important data for a better understanding of human renin gene expression. © 2004 Wiley‐Liss, Inc.     

Sequence analysis of the promoter region of the glioblastoma derived T cell suppressor factor/transforming growth factor (TGF)-beta 2 gene reveals striking differences to the TGF-beta 1 and -beta 3 genes

Human glioblastoma cells secrete a factor termed glioblastoma derived T cell suppressor factor (G-TsF) or transforming growth factor beta 2 (TGF-beta 2) which inhibits the response of T cells to mitogenic or antigenic stimulation. In the present study we isolated the promoter region of the G-TsF/TGF-beta 2 gene. The promoter region shares no homology to the promoter of the TGF-beta 1 or the 5' region of the TGF-beta 3 gene and harbours several familiar DNA motifs, including the cytokine-1 region, an octamer-like sequence, Sp1- and AP-2-like elements and a putative NF-kappa B site. In contrast to the TGF-beta 1 gene, the G-TsF/TGF-beta 2 gene contains three TATA-like sequences but lacks an AP-1 site. To understand the cell type specificity of expression of G-TsF/TGF-beta 2, the individual contribution of the DNA elements detected in the promoter has to be analysed in further studies.     

人NFBD1启动子的鉴定与初步分析

NFBD1,也称MDC1,是一个参与细胞内DNA损伤后细胞应答反应的重要分子.为了进一步深入研究其转录调控机制,本研究克隆鉴定了NFBD1的启动子.首先应用5′ RACE技术鉴定了NFBD1的转录起始位点,首次发现NFBD1至少存在3种丰度和转录起始位点不同的转录变异体.然后,通过PCR定向克隆和酶切亚克隆策略,构建了覆盖NFBD1基因5′侧翼区起始密码子ATG上游5 kb区域的一系列NFBD1启动子荧光素酶报告基因重组体.启动子活性分析表明,NFBD1启动子区域定位于主要转录起始位点区域附近1.5 kb的区域内.采用转录因子结合位点预测分析软件分析表明,NFBD1启动子缺乏TATA盒,但含有典型的CCAAT盒和GC盒以及其它潜在的转录因子结合位点,提示Sp1和NF-Y等转录因子可能参与NFBD1的转录调控