Paniagua Candelas, Bilkova Anna, Jackson Phil, Dabravolski Siarhei, Riber Willi, Didi Vojtech, Houser Josef, Gigli-Bisceglia Nora, Wimmerova Michaela, Budínská Eva, Hamann Thorsten, Hejatko Jan
Laboratory of Molecular Plant Physiology and Functional Genomics and Proteomics of Plants, CEITEC-Central European Institute of Technology and National Centre for Biomolecular Research, Masaryk University Kamenice 5, CZ-625 00 Brno, Czech Republic.
Research Centre for Toxic Compounds in the Environment (RECETOX), Masaryk University Kamenice 5, CZ-625 00 Brno, Czech Republic.
J Exp Bot. 2017 Jun 15;68(13):3287-3301. doi: 10.1093/jxb/erx141.
Dirigent (DIR) proteins were found to mediate regio- and stereoselectivity of bimolecular phenoxy radical coupling during lignan biosynthesis. Here we summarize the current knowledge of the importance of DIR proteins in lignan and lignin biosynthesis and highlight their possible importance in plant development. We focus on the still rather enigmatic Arabidopsis DIR gene family, discussing the few members with known functional importance. We comment on recent discoveries describing the detailed structure of two DIR proteins with implications in the mechanism of DIR-mediated catalysis. Further, we summarize the ample evidence for stress-induced dirigent gene expression, suggesting the role of DIRs in adaptive responses. In the second part of our work, we present a preliminary bioinformatics-based characterization of the AtDIR family. The phylogenetic analysis of AtDIRs complemented by comparison with DIR proteins of mostly known function from other species allowed us to suggest possible roles for several members of this family and identify interesting AtDIR targets for further study. Finally, based on the available metadata and our in silico analysis of AtDIR promoters, we hypothesize about the existence of specific transcriptional controls for individual AtDIR genes and implicate them in various stress responses, hormonal regulations, and developmental processes.
已发现 dirigent（DIR）蛋白在木脂素生物合成过程中介导双分子苯氧基自由基偶联的区域选择性和立体选择性。在此，我们总结了目前关于 DIR 蛋白在木脂素和木质素生物合成中的重要性的知识，并强调了它们在植物发育中的潜在重要性。我们聚焦于仍然相当神秘的拟南芥 DIR 基因家族，讨论了少数具有已知功能重要性的成员。我们对最近描述两种 DIR 蛋白详细结构及其对 DIR 介导催化机制影响的发现进行了评论。此外，我们总结了大量关于胁迫诱导 DIR 基因表达的证据，表明 DIR 在适应性反应中的作用。在我们工作的第二部分，我们基于生物信息学对 AtDIR 家族进行了初步表征。通过与来自其他物种的大多具有已知功能的 DIR 蛋白进行比较，对 AtDIR 进行系统发育分析，这使我们能够推测该家族几个成员的可能作用，并确定值得进一步研究的有趣的 AtDIR 靶点。最后，基于现有的元数据以及我们对 AtDIR 启动子的计算机分析，我们推测单个 AtDIR 基因存在特定的转录调控，并认为它们参与各种胁迫反应、激素调节和发育过程。
