Jupin I, Chua N H
Laboratory of Plant Molecular Biology, Rockefeller University, New York, NY 10021, USA.
EMBO J. 1996 Oct 15;15(20):5679-89.
Transcription from the as-1 element of the cauliflower mosaic virus is induced by salicylic acid (SA), an endogenous signal involved in plant defence responses. Electrophoretic mobility shift assays demonstrated that the binding of a tobacco cellular factor, named SARP, correlates with the SA-induced activation of transcription. SARP was shown to contain proteins immunologically related to TGA1a, a transcription factor previously cloned for its ability to bind to the as-1 element. The molecular mass of SARP was estimated to be 40 kDa by South-Western experiments. Treatment of the extracts with dissociating agents led to an increase in the DNA binding activity, suggesting the presence of an inhibitor that sequesters SARP. The DNA binding activity appeared sensitive to phosphatase treatment, suggesting a role for phosphorylation in the SA-induced gene activation. These results represent an analysis of immediate early response to SA and potentially elucidate the events of the SA signal transduction pathway.
水杨酸（SA）可诱导花椰菜花叶病毒as-1元件的转录，SA是一种参与植物防御反应的内源性信号。电泳迁移率变动分析表明，一种名为SARP的烟草细胞因子的结合与SA诱导的转录激活相关。结果显示，SARP含有与TGA1a免疫相关的蛋白质，TGA1a是先前因其与as-1元件结合的能力而被克隆的转录因子。通过South-Western实验估计SARP的分子量为40 kDa。用解离剂处理提取物导致DNA结合活性增加，表明存在一种隔离SARP的抑制剂。DNA结合活性似乎对磷酸酶处理敏感，表明磷酸化在SA诱导的基因激活中起作用。这些结果代表了对SA即时早期反应的分析，并可能阐明SA信号转导途径的事件。
