Hatton D, Sablowski R, Yung M H, Smith C, Schuch W, Bevan M
Molecular Genetics Department, John Innes Centre, Norwich, UK.
Plant J. 1995 Jun;7(6):859-76. doi: 10.1046/j.1365-313x.1995.07060859.x.
Genes encoding phenylalanine ammonia-lyase (PAL) are expressed in a complex pattern during plant development and in response to light, pathogen ingress, mechanical damage and other stresses. Analysis of the promoter of the bean PAL2 gene in transgenic tobacco has shown that some regions responsible for developmental expression are functionally compensatory. The minimum sequence containing all cis sequences necessary for developmental patterns of expression is within -254 bp of the transcription start site. Footprinting and electrophoretic mobility shift assay studies of this region revealed potential cis sequences which coincided with the functional domains defined by small deletions and promoter fusions. Mutations in these potential cis sequences in the context of the minimal -254 bp promoter altered tissue-specific expression patterns, confirming the importance of these sequences for expression in vivo. A functional model for the promoter is presented which predicts that three AC-elements, which are possible Myb protein binding sites, together with a G-box, interact to direct the complex patterns of tissue-specific expression observed.
编码苯丙氨酸解氨酶（PAL）的基因在植物发育过程中以及对光、病原体入侵、机械损伤和其他胁迫的响应中以复杂的模式表达。对转基因烟草中豆类PAL2基因启动子的分析表明，一些负责发育表达的区域具有功能补偿性。包含表达发育模式所需所有顺式序列的最小序列在转录起始位点的-254 bp范围内。对该区域的足迹分析和电泳迁移率变动分析研究揭示了潜在的顺式序列，这些序列与由小缺失和启动子融合定义的功能域一致。在最小的-254 bp启动子背景下，这些潜在顺式序列中的突变改变了组织特异性表达模式，证实了这些序列在体内表达中的重要性。提出了一个启动子的功能模型，该模型预测三个AC元件（可能是Myb蛋白结合位点）与一个G盒相互作用，以指导观察到的组织特异性表达的复杂模式。
