Chalcone synthase is ubiquitinated and degraded via interactions with a RING-H2 protein in petals of Paeonia 'He Xie'
Chalcone synthase is ubiquitinated and degraded via interactions with a RING-H2 protein in petals of Paeonia 'He Xie'
复制标题
查耳酮合酶通过与“何协”芍药花瓣中的 RING-H2 蛋白相互作用而被泛素化和降解
DOI：
10.1093/jxb/erz245
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发表时间：
2019-09-15
影响因子：
6.9
通讯作者：
Wang, Liangsheng
中科院分区：
文献类型：
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作者：
Gu, Zhaoyu;Men, Siqi;Wang, Liangsheng
黄酮类化合物是广泛存在于被子植物中的次生代谢物，在植物的生长、发育和进化中发挥着不同的作用。植物类黄酮生物合成的调控已经在转录水平上得到了广泛的研究，但对类黄酮生物合成的转录后、翻译后和翻译后控制仍知之甚少。在这项研究中，我们利用蛋白质组和泛素组图谱，结合转录组数据，分析了观赏植物牡丹类黄酮生物合成的翻译后调节。参与类黄酮生物合成的三种酶被确定为泛素介导的降解靶标。其中查尔酮合酶(PhCHS)具有最多的泛素化位点。我们使用PhCHS特异性抗体检测了花瓣中PhCHS的丰度，发现在发育后期，由于26S蛋白酶体介导的降解，其积累减少。我们进一步鉴定了一个环状结构域蛋白(PhRING-H2)，它与PhCHS物理上相互作用，并证明了PhCHS泛素化需要PhRING-H2。综上所述，我们的结果表明，PhRING-H2-介导的PhCHS泛素化和降解是牡丹类黄酮生物合成的翻译后调控的重要机制，为植物类黄酮生物合成的调控提供了理论基础。
Flavonoids are secondary metabolites widely distributed among angiosperms, where they play diverse roles in plant growth, development, and evolution. The regulation of flavonoid biosynthesis in plants has been extensively studied at the transcriptional level, but post-transcriptional, translational, and post-translational control of flavonoid biosynthesis remain poorly understood. In this study, we analysed post-translational regulation of flavonoid biosynthesis in the ornamental plant Paeonia, using proteome and ubiquitylome profiling, in conjunction with transcriptome data. Three enzymes involved in flavonoid biosynthesis were identified as being putative targets of ubiquitin-mediated degradation. Among these, chalcone synthase (PhCHS) was shown to have the greatest number of ubiquitination sites. We examined PhCHS abundance in petals using PhCHS-specific antibody and found that its accumulation decreased at later developmental stages, resulting from 26S proteasome-mediated degradation. We further identified a ring domain-containing protein (PhRING-H2) that physically interacts with PhCHS and demonstrated that PhRING-H2 is required for PhCHS ubiquitination. Taken together, our results suggest that PhRING-H2-mediates PhCHS ubiquitination and degradation is an important mechanism of post-translational regulation of flavonoid biosynthesis in Paeonia, providing a theoretical basis for the manipulation of flavonoid biosynthesis in plants.