Terpenoid biosynthesis in the cultivated mushroom Cyclocybe aegerita

萜类化合物构成了一组结构多样的天然产物，在制药、营养、调味和香料工业中具有不可或缺的应用。已知担子菌门的真菌产生大量种类的萜类化合物，但它们的生物合成途径仍然在很大程度上未被探索。蘑菇模式系统Cyclocybe aegerita（syn.茶树菇（Agrocybe aegerita）含有九种功能性倍半萜烯脱氢酶（STS），其中四种是生物合成基因簇的一部分。通过这些簇在相关模式真菌灰盖鬼伞中的异源表达，将详细研究这些生物合成途径的独特特性。1)最近检测到的boviferase A-C是由Diels-Alderase组装的，其底物谱将通过体外反应来确定。2)它们的隐色菌素前体含有一个三元环结构，这是它们强烈的细胞毒性作用的原因。尽管这种骨架在真菌中分布非常广泛，但显然由P450型单加氧酶催化的关键环收缩反应仍然是一个谜。3)C. aegerita，预计将由具有特征的STS Agr 2生产。我们将研究这种酶是否接受香叶基香叶基焦磷酸除了法呢焦磷酸。由于我们确定了挥发性和非挥发性次级代谢产物的结构和生物活性，我们不仅可以进一步挖掘食用菌C的次级代谢物组。aegerita，但也试图了解一般的一个典型的担子菌类萜类生物合成。

Terpenoids constitute a structurally diverse group of natural products with indispensable applications in the pharmaceutical, nutritional, flavour and fragrance industries. Fungi of the phylum Basidiomycota are known to produce a large variety of terpenoids, yet their biosynthesis pathways remain largely unexplored. The genome of the mushroom model system Cyclocybe aegerita (syn. Agrocybe aegerita) contains nine functional sesquiterpene synthases (STS), of which four are part of biosynthetic gene clusters. By the heterologous expression of these clusters in the related model agaric fungus Coprinopsis cinerea, the peculiar characteristics of these biosynthesis pathways will be investigated in detail. 1) The recently detected bissesquiterpenoids bovistol A-C are assembled by a Diels-Alderase, whose substrate spectrum will be determined by in vitro reactions. 2) Their illudin-precursors contain a three-membered ring structure, which is responsible for their strong cytotoxic effects. Despite the very broad distribution of this skeletal in fungi, the key ring contraction reaction catalysed apparently by P450-type monooxygenases remains an enigma. 3) A new viridiflorene-based diterpene is produced by C. aegerita, which is expected to be produced by the characterised STS Agr2. We will investigate whether this enzyme accepts geranylgeranyl pyrophosphate in addition to farnesyl pyrophosphate. Since we determine the structures and bioactivities of both volatile and non-volatile secondary metabolite products, we will not only further tap the secondary metabolome of the edible mushroom C. aegerita, but also seek to understand the terpenoid biosynthesis of a typical Basidiomycota in general.