Tjaden G, Coruzzi G M
Department of Biology, New York University, New York 10003.
Plant Cell. 1994 Jan;6(1):107-18. doi: 10.1105/tpc.6.1.107.
There is growing evidence that AT-rich promoter elements play a role in transcription of plant genes. For the promoter of the nuclear gene for chloroplast glutamine synthetase from pea (GS2), the deletion of a 33-bp AT-rich sequence (box 1 native) from the 5' end of a GS2 promoter-beta-glucuronidase (GUS) fusion resulted in a 10-fold reduction in GUS activity. The box 1 native element was used in gel shift analysis and two distinct complexes were detected. One complex is related to the low-mobility complex reported previously for AT-rich elements from several other plant promoters. A multimer of the box 1 sequence was used to isolate a cDNA encoding an AT-rich DNA binding protein (ATBP-1). ATBP-1 is not a high-mobility group protein, but it is a novel protein that combines a high-mobility group I/Y-like DNA binding domain with a glutamine-rich putative transcriptional domain.
越来越多的证据表明，富含AT的启动子元件在植物基因转录中发挥作用。对于豌豆叶绿体谷氨酰胺合成酶（GS2）核基因的启动子，从GS2启动子-β-葡萄糖醛酸酶（GUS）融合体的5'端缺失一个33bp富含AT的序列（天然框1）导致GUS活性降低10倍。天然框1元件用于凝胶迁移分析，检测到两种不同的复合物。一种复合物与先前报道的来自其他几种植物启动子的富含AT元件的低迁移率复合物有关。框1序列的多聚体用于分离编码富含AT的DNA结合蛋白（ATBP-1）的cDNA。ATBP-1不是高迁移率族蛋白，而是一种新型蛋白，它将高迁移率族I/Y样DNA结合结构域与富含谷氨酰胺的假定转录结构域结合在一起。
