Department for Evolutionary Biology, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany.
Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA.
Cell Chem Biol. 2018 Jun 21;25(6):787-796.e12. doi: 10.1016/j.chembiol.2018.04.004. Epub 2018 May 17.
In the nematodes Caenorhabditis elegans and Pristionchus pacificus, a modular library of small molecules control behavior, lifespan, and development. However, little is known about the final steps of their biosynthesis, in which diverse building blocks from primary metabolism are attached to glycosides of the dideoxysugar ascarylose, the ascarosides. We combine metabolomic analysis of natural isolates of P. pacificus with genome-wide association mapping to identify a putative carboxylesterase, Ppa-uar-1, that is required for attachment of a pyrimidine-derived moiety in the biosynthesis of ubas#1, a major dauer pheromone component. Comparative metabolomic analysis of wild-type and Ppa-uar-1 mutants showed that Ppa-uar-1 is required specifically for the biosynthesis of ubas#1 and related metabolites. Heterologous expression of Ppa-UAR-1 in C. elegans yielded a non-endogenous ascaroside, whose structure confirmed that Ppa-uar-1 is involved in modification of a specific position in ascarosides. Our study demonstrates the utility of natural variation-based approaches for uncovering biosynthetic pathways.
在秀丽隐杆线虫和太平洋真涡虫中，一个小分子的模块化文库控制着行为、寿命和发育。然而，对于它们生物合成的最后步骤知之甚少，在这个步骤中，来自初级代谢物的各种构建块被连接到二脱氧糖 ascarylose（阿聚糖）的糖苷上，形成 ascariosides。我们将太平洋真涡虫天然分离株的代谢组学分析与全基因组关联图谱分析相结合，鉴定出一个假定的羧酸酯酶 Ppa-uar-1，它是合成 ubas#1（一种主要的 dauer 信息素成分）过程中嘧啶衍生部分连接所必需的。野生型和 Ppa-uar-1 突变体的比较代谢组学分析表明，Ppa-uar-1 特异性地参与了 ubas#1 和相关代谢物的生物合成。在秀丽隐杆线虫中异源表达 Ppa-UAR-1 产生了一种非内源性 ascarioside，其结构证实 Ppa-uar-1 参与了 ascarioside 特定位置的修饰。我们的研究证明了基于自然变异的方法在揭示生物合成途径方面的实用性。
