Dean G, Young D A, Edwards D R, Clark I M
School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, United Kingdom.
J Biol Chem. 2000 Oct 20;275(42):32664-71. doi: 10.1074/jbc.275.42.32664.
Expression of the TIMP-1 (tissue inhibitor of metalloproteinases-1) gene is tightly controlled during embryonic development and in the adult animal. Previous studies have focused on elements within the gene promoter which activate transcription of the gene. Here, we identify two regions of the gene which repress transcription: An element upstream of the basal gene promoter at -1718/-1458, represses expression of a reporter gene by approximately 50%; addition of the first intron to any promoter-reporter construct also strongly represses gene expression. The TIMP-1 gene has a short first exon which is transcribed but not translated, with the translation start site located in exon 2. Deletion analysis through intron 1 reveals a number of potential regions which might mediate its effect. Protein binding studies and mutational analyses reveal that a repressive element at +684/+748 binds Sp1, Sp3, and an unidentified Ets-related factor to suppress transcription.
金属蛋白酶组织抑制剂-1（TIMP-1）基因的表达在胚胎发育过程和成年动物体内受到严格调控。以往的研究集中在基因启动子内激活该基因转录的元件上。在此，我们鉴定出该基因的两个抑制转录的区域：位于基础基因启动子上游-1718/-1458处的一个元件，可使报告基因的表达降低约50%；将第一个内含子添加到任何启动子-报告基因构建体中也会强烈抑制基因表达。TIMP-1基因有一个短的第一外显子，它被转录但不被翻译，翻译起始位点位于外显子2中。通过内含子1进行的缺失分析揭示了一些可能介导其作用的潜在区域。蛋白质结合研究和突变分析表明，位于+684/+748处的一个抑制元件可结合Sp1、Sp3和一个未鉴定的Ets相关因子以抑制转录。
