Pauw Bea, Hilliou Frédérique A O, Martin Virginia Sandonis, Chatel Guillaume, de Wolf Cocky J F, Champion Antony, Pré Martial, van Duijn Bert, Kijne Jan W, van der Fits Leslie, Memelink Johan
Institute of Biology, Leiden University, Clusius Laboratory, Wassenaarseweg 64, 2333 AL Leiden, The Netherlands.
J Biol Chem. 2004 Dec 17;279(51):52940-8. doi: 10.1074/jbc.M404391200. Epub 2004 Oct 1.
In Catharanthus roseus cell suspensions, the expression of several terpenoid indole alkaloid biosynthetic genes, including two genes encoding strictosidine synthase (STR) and tryptophan decarboxylase (TDC), is coordinately induced by fungal elicitors such as yeast extract. To identify molecular mechanisms regulating the expression of these genes, a yeast one-hybrid screening was performed with an elicitor-responsive part of the TDC promoter. This screening identified three members of the Cys(2)/His(2)-type (transcription factor IIIA-type) zinc finger protein family from C. roseus, ZCT1, ZCT2, and ZCT3. These proteins bind in a sequence-specific manner to the TDC and STR promoters in vitro and repress the activity of these promoters in trans-activation assays. In addition, the ZCT proteins can repress the activating activity of APETALA2/ethylene response-factor domain transcription factors, the ORCAs, on the STR promoter. The expression of the ZCT genes is rapidly induced by yeast extract and methyljasmonate. These results suggest that the ZCT proteins act as repressors in the regulation of elicitor-induced secondary metabolism in C. roseus.
在长春花细胞悬浮液中，几种萜类吲哚生物碱生物合成基因的表达，包括两个编码异胡豆苷合酶（STR）和色氨酸脱羧酶（TDC）的基因，受到酵母提取物等真菌激发子的协同诱导。为了确定调控这些基因表达的分子机制，利用TDC启动子的激发子响应部分进行了酵母单杂交筛选。该筛选从长春花中鉴定出了Cys(2)/His(2)型（转录因子IIIA型）锌指蛋白家族的三个成员，即ZCT1、ZCT2和ZCT3。这些蛋白在体外以序列特异性方式与TDC和STR启动子结合，并在反式激活试验中抑制这些启动子的活性。此外，ZCT蛋白可以抑制APETALA2/乙烯响应因子结构域转录因子ORCAs对STR启动子的激活活性。ZCT基因的表达受到酵母提取物和茉莉酸甲酯的快速诱导。这些结果表明，ZCT蛋白在长春花激发子诱导的次生代谢调控中起阻遏作用。
