Sawant Samir V, Kiran Kanti, Mehrotra Rajesh, Chaturvedi Chandra Prakash, Ansari Suraiya A, Singh Pratibha, Lodhi Niraj, Tuli Rakesh
National Botanical Research Institute, Rana Pratap Marg, Lucknow-226001, India.
J Exp Bot. 2005 Sep;56(419):2345-53. doi: 10.1093/jxb/eri227. Epub 2005 Jul 12.
Several synthetic promoters containing a variety of commonly found cis-acting DNA sequence motifs were constructed to study the motif-motif and motif-protein interactions involved in gene expression in plants. Transient expression of the reporter gene gusA in tobacco leaves was used to demonstrate that several sequence elements can be arranged upstream of a basal promoter to function synergistically in enhancing gene expression. A cis-acting DNA motif could function as an activator by itself as well as a synergizing activator in the presence of other homologous as well as heterologous motifs in the neighbourhood. The function of a complex promoter comprising several activation motifs was arrested nearly completely in vivo, following titration with any one of the motifs. The results suggested a hierarchical assembly of several motif-binding factors, leading to the stabilization of the transcriptional complex formed on the TATA-box.
构建了几个含有多种常见顺式作用DNA序列基序的合成启动子，以研究植物基因表达中涉及的基序-基序和基序-蛋白质相互作用。利用报告基因gusA在烟草叶片中的瞬时表达来证明，几个序列元件可以排列在基础启动子上游，协同发挥作用以增强基因表达。一个顺式作用DNA基序本身可以作为激活剂，在其附近存在其他同源和异源基序时也可以作为协同激活剂。在用任何一个基序进行滴定后，包含几个激活基序的复合启动子的功能在体内几乎完全被抑制。结果表明存在几个基序结合因子的分级组装，导致在TATA盒上形成的转录复合物的稳定。
