Repression of the defense gene PR-10a by the single-stranded DNA binding protein SEBF.
Repression of the defense gene PR-10a by the single-stranded DNA binding protein SEBF.
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DOI：
10.2307/3871592
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发表时间：
2001
期刊：
影响因子：
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通讯作者：
B. Boyle;N. Brisson
中科院分区：
文献类型：
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作者：
B. Boyle;N. Brisson
马铃薯病程相关基因PR-10a在病原菌感染或诱导子处理时被转录激活。PR-10a启动子的顺式作用元件的表征揭示了在残基-52和-27之间存在沉默元件，其有助于转录调节。在这项研究中，我们已经分离出沉默元件结合因子（SEBF）从马铃薯块茎细胞核结合到沉默元件的编码链在一个序列特异性的方式。SEBF的共有结合位点PyTGTCNC存在于许多PR基因中，并且与生长素反应元件显示出惊人的相似性。PR-10a启动子的突变分析揭示了SEBF的体外结合与PR-10a的表达之间的负相关。从马铃薯块茎中纯化SEBF至同质，并对该蛋白的N末端进行测序，从而分离出cDNA克隆。序列分析表明，SEBF是同源的叶绿体RNA结合蛋白，具有一致的序列类型的RNA结合结构域的特征的异质性核核糖核蛋白（hnRNP）。SEBF在原生质体中的过表达以沉默元件依赖的方式抑制PR-10a报告构建体的活性，证实了SEBF作为转录抑制因子的作用。
The potato pathogenesis-related gene PR-10a is transcriptionally activated in response to pathogen infection or elicitor treatment. Characterization of the cis-acting elements of the PR-10a promoter revealed the presence of a silencing element between residues -52 and -27 that contributes to transcriptional regulation. In this study, we have isolated a silencing element binding factor (SEBF) from potato tuber nuclei that binds to the coding strand of the silencing element in a sequence-specific manner. The consensus binding site of SEBF, PyTGTCNC, is present in a number of PR genes and shows striking similarity to the auxin response element. Mutational analysis of the PR-10a promoter revealed an inverse correlation between the in vitro binding of SEBF and the expression of PR-10a. SEBF was purified to homogeneity from potato tubers, and sequencing of the N terminus of the protein led to the isolation of a cDNA clone. Sequence analysis revealed that SEBF is homologous with chloroplast RNA binding proteins that possess consensus sequence-type RNA binding domains characteristic of heterogeneous nuclear ribonucleoproteins (hnRNPs). Overexpression of SEBF in protoplasts repressed the activity of a PR-10a reporter construct in a silencing element-dependent manner, confirming the role of SEBF as a transcriptional repressor.