Takatsuji H, Mori M, Benfey P N, Ren L, Chua N H
Laboratory of Plant Molecular Biology, Rockefeller University, New York, NY 10021.
EMBO J. 1992 Jan;11(1):241-9. doi: 10.1002/j.1460-2075.1992.tb05047.x.
In Petunia, the expression of the 5-enolpyruvylshikimate-3-phosphate synthase gene (EPSPS) is tissue-specific and developmentally regulated. Nuclear extracts from Petunia petal contain a factor that interacts with the 5' upstream region of EPSPS. DNase I footprinting experiments revealed four strong binding sites (EP1-EP4) and several weaker sites that appear to bind the same factor. We have isolated a cDNA clone (EPF1) encoding a DNA-binding protein that has similar binding activity to that of the nuclear factor. The deduced amino acid sequence shows that the encoded protein, EPF1, contains two repeats of a Cys2/His2 zinc finger motif. EPF1 and the factor detected in nuclear extracts appear to differ in their molecular weight and Zn2+ requirements. Nevertheless, Northern blot analyses showed that the expression pattern of EPF1 is remarkably similar to that of EPSPS. In addition, as determined by translational fusion of the EPF1 upstream region to the beta-glucuronidase reporter gene, the cell specific expression pattern of EPF1 in flower and seedling is nearly identical to that of EPSPS. Taken together with the results of cis-element analyses, these observations suggest that EPF1 may be one of the factors involved in the activation of EPSPS.
在矮牵牛中，5-烯醇丙酮酰莽草酸-3-磷酸合酶基因（EPSPS）的表达具有组织特异性且受发育调控。矮牵牛花瓣的核提取物含有一种与EPSPS 5'上游区域相互作用的因子。DNA酶I足迹实验揭示了四个强结合位点（EP1-EP4）和几个较弱的位点，这些位点似乎结合相同的因子。我们分离出了一个编码DNA结合蛋白的cDNA克隆（EPF1），该蛋白具有与核因子相似的结合活性。推导的氨基酸序列表明，编码的蛋白EPF1包含两个Cys2/His2锌指基序重复。EPF1和在核提取物中检测到的因子在分子量和锌离子需求方面似乎有所不同。然而，Northern印迹分析表明，EPF1的表达模式与EPSPS的表达模式非常相似。此外，通过将EPF1上游区域与β-葡萄糖醛酸酶报告基因进行翻译融合测定，EPF1在花和幼苗中的细胞特异性表达模式与EPSPS几乎相同。结合顺式元件分析结果，这些观察结果表明EPF1可能是参与激活EPSPS的因子之一。
