Department of Biological Sciences, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931, USA.
Gene. 2013 Sep 10;526(2):400-10. doi: 10.1016/j.gene.2013.05.060. Epub 2013 Jun 10.
Bidirectional promoters are defined as those that regulate adjacent genes organized in a divergent fashion (head to head orientation) and separated by <1 kb. In order to dissect bidirectional promoter activity in a model plant, deletion analysis was performed for seven rice promoters using promoter-reporter gene constructs, which identified three promoters to be bidirectional. Regulatory elements located in or close to the 5'-untranslated regions (UTR) of one of the genes (divergent gene pair) were found to be responsible for their bidirectional activity. DNA footprinting analysis identified unique protein binding sites in these promoters. Deletion/alteration of these motifs resulted in significant loss of expression of the reporter genes on either side of the promoter. Changes in the motifs at both the positions resulted in a remarkable decrease in bidirectional activity of the reporter genes flanking the promoter. Based on our results, we propose a novel mechanism for the bidirectionality of rice bidirectional promoters.
双向启动子被定义为那些调节以发散方式（头对头取向）组织的相邻基因的启动子，它们之间的间隔小于 1 kb。为了在模式植物中剖析双向启动子的活性，使用启动子-报告基因构建体对七个水稻启动子进行了缺失分析，鉴定出三个启动子为双向启动子。位于一个基因（发散基因对）的 5'非翻译区（UTR）内或附近的调节元件负责其双向活性。DNA 足迹分析在这些启动子中鉴定出了独特的蛋白结合位点。这些基序的缺失/改变导致报告基因在启动子两侧的表达显著丧失。在这两个位置上的基序的改变导致了侧翼启动子的报告基因的双向活性显著降低。基于我们的结果，我们提出了一个用于水稻双向启动子双向性的新机制。
