A novel transcriptional regulator RXE1 modulates the essential transactivator XYR1 and cellulase gene expression in Trichoderma reesei
A novel transcriptional regulator RXE1 modulates the essential transactivator XYR1 and cellulase gene expression in Trichoderma reesei
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一种新型转录调节因子 RXE1 调节里氏木霉中必需的反式激活因子 XYR1 和纤维素酶基因表达
DOI：
10.1007/s00253-019-09739-6
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发表时间：
2019-06-01
影响因子：
5
通讯作者：
Zhang, Weixin
中科院分区：
文献类型：
--
作者：
Wang, Lei;Lv, Xinxing;Zhang, Weixin
XYR1是模型丝状真菌里氏木霉中纤维素酶基因表达的关键转录激活因子，因其具有大量分泌纤维素酶的优异能力而在工业上得到广泛应用。尽管XYR1发挥着重要的作用，但其表达调控在芦荻纤维素水解反应中的作用尚不清楚。在本研究中，我们通过酵母单杂交筛选，发现了一个与xyr1启动子结合活性较强的转录因子RXE1。RXE1同源物存在于相当多的丝状真菌中，但尚未对其参与植物细胞壁降解的功能进行评估。使用铜介导的RNAi系统敲除rxe1不仅可以消除条件，还可以显著降低xyr1和纤维素酶基因的表达。在rxe1敲低菌株中，XYR1的组成表达完全恢复了缺陷的纤维素酶，而不是分生孢子的产生。因此，我们的研究发现了一个新的调控xyr1和纤维素酶基因表达的转录调控因子，这将有助于阐明纤维素酶基因调控的复杂网络。
XYR1 is the key transcription activator for cellulase gene expression in the model filamentous fungus Trichoderma reesei, which is widely applied in the industry due to its excellent capability of secreting a large quantity of cellulases. Despite the essential role of XYR1, the regulation of its expression in T. reesei cellulolytic response is poorly understood. In this study, we identified a transcription factor RXE1 exhibiting strong binding activity to the xyr1 promoter using yeast one-hybrid screen. RXE1 homologs exist in quite a few filamentous fungi but none of them have been assessed regarding their functional involvement in plant cell wall degradation. Knockdown of rxe1 in T. reesei using a copper-mediated RNAi system not only abrogated conidiation, but also remarkably compromised xyr1 and cellulase gene expression. The defective cellulase but not conidia production in the rxe1-knockdown strain was fully rescued by the constitutive expression of XYR1. Our study thus identified a novel transcriptional regulator controlling xyr1 and cellulase gene expression, which will contribute to elaborating the intricate network of cellulase gene regulation in T. reesei.