A Copal-8-ol Diphosphate Synthase from the Angiosperm Cistus creticus subsp creticus Is a Putative Key Enzyme for the Formation of Pharmacologically Active, Oxygen-Containing Labdane-Type Diterpenes
A Copal-8-ol Diphosphate Synthase from the Angiosperm Cistus creticus subsp creticus Is a Putative Key Enzyme for the Formation of Pharmacologically Active, Oxygen-Containing Labdane-Type Diterpenes
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DOI：
10.1104/pp.110.159566
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发表时间：
2010-09-01
期刊：
影响因子：
7.4
通讯作者：
Kanellis, Angelos K.
中科院分区：
文献类型：
--
作者：
Falara, Vasiliki;Pichersky, Eran;Kanellis, Angelos K.
Cistus creticus subsp. 的树脂。 creticus 是一种原产于克里特岛的植物，富含拉丹丹型二萜，具有显着的抗菌和细胞毒活性。从 C. creticus 毛状体 cDNA 文库中分离出推定二萜合酶的全长 cDNA。该蛋白的推导氨基酸序列与来自其他被子植物物种的催化质子化引发环化的 B 型二萜合酶高度相似（59%-70% 相同）。亲和纯化的重组大肠杆菌表达蛋白以香叶基香叶基二磷酸为底物，催化8-醇二磷酸的形成。因此，这种二萜合酶被命名为 CcCLS（C. creticus copal-8-ol 二磷酸合酶）。 Copal-8-ol 二磷酸可能是该植物树脂中丰富的含氧劳丹烷型二萜生物合成的中间体。 RNA凝胶印迹分析显示，CcCLS优先在毛状体中表达，幼叶腺体中的转录水平高于完全展开的叶子，而机械损伤后CcCLS转录水平增加。化学分析表明，拉丹丹型二萜的产生遵循类似的模式，幼叶毛状体中的浓度较高，并且受伤时积累增加。
The resin of Cistus creticus subsp. creticus, a plant native to Crete, is rich in labdane-type diterpenes with significant antimicrobial and cytotoxic activities. The full-length cDNA of a putative diterpene synthase was isolated from a C. creticus trichome cDNA library. The deduced amino acid sequence of this protein is highly similar (59%-70% identical) to type B diterpene synthases from other angiosperm species that catalyze a protonation-initiated cyclization. The affinity-purified recombinant Escherichia coli-expressed protein used geranylgeranyl diphosphate as substrate and catalyzed the formation of copal-8-ol diphosphate. This diterpene synthase, therefore, was named CcCLS (for C. creticus copal-8-ol diphosphate synthase). Copal-8-ol diphosphate is likely to be an intermediate in the biosynthesis of the oxygen-containing labdane-type diterpenes that are abundant in the resin of this plant. RNA gel-blot analysis revealed that CcCLS is preferentially expressed in the trichomes, with higher transcript levels found in glands on young leaves than on fully expanded leaves, while CcCLS transcript levels increased after mechanical wounding. Chemical analyses revealed that labdane-type diterpene production followed a similar pattern, with higher concentrations in trichomes of young leaves and increased accumulation upon wounding.