Korfhage U, Trezzini G F, Meier I, Hahlbrock K, Somssich I E
Max-Planck-Institut für Züchtungsforschung, Abteilung Biochemie, Köln, Germany.
Plant Cell. 1994 May;6(5):695-708. doi: 10.1105/tpc.6.5.695.
Transcription of the parsley pr2 gene, encoding pathogenesis-related protein 2 (PR2), is rapidly stimulated by fungal or bacterial elicitors. Previous work has revealed a 125-bp region within the pr2 promoter; this region encompasses all important cis-regulatory elements required for fungal elicitor-mediated expression. We now report the identification of a functionally relevant 11-bp DNA motif (CTAATTGTTTA) contained within this region; it specifically binds to factors present in both parsley and Arabidopsis nuclear protein extracts. From both plant species, full-length cDNA clones were isolated that encode proteins with high affinity fo this DNA motif. The proteins from both species contain stretches of 61 amino acids that are characteristic of homeodomain (HD) proteins. Binding studies and use of a polyclonal antiserum raised against a fusion polypeptide of glutathione S-transferase with the HD portion of the parsley protein indicated that the 11-bp DNA motif is a potential in vivo target site and that the HD protein is contained within the observed complex formed between the DNA motif and nuclear protein extracts. Transient expression studies using the authentic and a mutated target site suggested a functional role of the HD-DNA interaction in the regulation of the pr2 gene expression.
编码病程相关蛋白2（PR2）的欧芹pr2基因的转录受到真菌或细菌激发子的快速刺激。先前的研究揭示了pr2启动子内一个125bp的区域；该区域包含真菌激发子介导表达所需的所有重要顺式调控元件。我们现在报告在该区域内鉴定出一个功能相关的11bp DNA基序（CTAATTGTTTA）；它特异性结合欧芹和拟南芥核蛋白提取物中存在的因子。从这两种植物中分离出全长cDNA克隆，其编码的蛋白质对该DNA基序具有高亲和力。这两种植物的蛋白质都含有一段61个氨基酸的序列，这是同源结构域（HD）蛋白的特征。结合研究以及使用针对谷胱甘肽S-转移酶与欧芹蛋白HD部分的融合多肽产生的多克隆抗血清表明，11bp DNA基序是一个潜在的体内靶位点，并且HD蛋白包含在DNA基序与核蛋白提取物形成的观察到的复合物中。使用真实和突变靶位点的瞬时表达研究表明HD-DNA相互作用在pr2基因表达调控中具有功能作用。
