Autoregulation of mouse BMP-2 gene transcription is directed by the proximal promoter element
Autoregulation of mouse BMP-2 gene transcription is directed by the proximal promoter element
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DOI：
10.1006/bbrc.2001.5351
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发表时间：
2001-08-10
影响因子：
3.1
通讯作者：
Harris, SE
中科院分区：
文献类型：
--
作者：
Ghosh-Choudhury, N;Choudhury, GG;Harris, SE
骨形态发生蛋白 2 (BMP-2) 刺激前体间充质细胞向成熟骨的定型和分化。我们分离并测序了小鼠 BMP-2 基因 5' 侧翼区域的 2712 个碱基对 (bp)。使用 RNase 保护测定，我们在 BAM-2 基因的这个 2712 bp 区域内鉴定了两个转录起始位点。相对于近端起始位点 (+1)，远端起始位点被映射到 -736 bp。重组 BMP-2 优先刺激近端起始位点的转录起始。为了研究从这两个起始位点开始转录的机制，我们鉴定了近端和远端转录起始位点上游的两个启动子元件。将启动子-荧光素酶报告基因构建体转染到不同器官的细胞中，显示近端和远端启动子的转录活性存在差异，其中在成骨细胞谱系中活性最高。在成骨细胞中，BMP-2 仅刺激近端启动子的转录。我们的数据共同提供了小鼠 BMP-2 基因中存在两个转录起始位点和两个上游启动子元件的第一个证据。此外，我们首次证明 BMP-2 通过近端启动子依赖性转录机制自动调节其在成骨细胞中的表达。 (C) 2001 年学术出版社。
Bone morphogenetic protein-2 (BMP-2) stimulates the commitment and differentiation of precursor mesenchymal cells to mature bone. We have isolated and sequenced 2712 base pairs (bp) of the 5 ' flanking region of mouse BMP-2 gene. Using RNase protection assay we identified two transcription initiation sites within this 2712 bp region of the BAM-2 gene. The distal start site was mapped to -736 bp in relation to the proximal start site (+1). Recombinant BMP-2 preferentially stimulated transcription initiation from the proximal start site. To investigate the mechanism of transcription initiation from these two start sites, we identified two promoter elements upstream of the proximal and distal transcription initiation sites. Transfection of promoter-luciferase reporter constructs into cells of different organs demonstrated differential transcriptional activity of proximal and distal promoters, with highest activity in the osteoblast cell lineage. In osteoblasts, BMP-2 stimulated transcription from the proximal promoter only. Together our data provide the first evidence for the presence of two transcription initiation sites with two upstream promoter elements in mouse BMP-2 gene. Furthermore, we demonstrate for the first time that BMP-2 autoregulates its expression in osteoblasts through the proximal promoter-dependent transcriptional mechanism. (C) 2001 Academic Press.