Isoquinoline Alkaloid Biosynthesis is Regulated by a Unique bHLH-Type Transcription Factor in Coptis japonica
Isoquinoline Alkaloid Biosynthesis is Regulated by a Unique bHLH-Type Transcription Factor in Coptis japonica
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DOI：
10.1093/pcp/pcr062
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发表时间：
2011-07-01
影响因子：
4.9
通讯作者：
Sato, Fumihiko
中科院分区：
文献类型：
--
作者：
Yamada, Yasuyuki;Kokabu, Yasuhisa;Sato, Fumihiko
特定的植物物种产生独特的异喹啉生物碱（IQAs）;然而，它们的进化机制和生物合成的调节在很大程度上是未知的。我们在这里报告的一种新的碱性螺旋-环-螺旋蛋白，CjbHLH 1，从生产IQA的日本黄连分离。BLAST搜索表明，CjbHLH 1同源物仅在产生IQAs的植物物种中发现。瞬时RNA干扰（RNAi）和CjbHLH 1在C. Japonica原生质体中发现CjbHLH 1在IQA生物合成基因的转录中具有活性，而在参与初级代谢或胁迫反应的基因的转录中几乎没有活性。使用CjbHLH 1特异性抗体的染色质免疫沉淀实验揭示了CjbHLH 1与IQA生物合成基因的启动子序列在体内的直接相互作用。我们讨论了CjbHLH 1在IQA生物合成中的独特作用。
Specific plant species produce unique isoquinoline alkaloids (IQAs); however, the mechanism of their evolution and the regulation of their biosynthesis are largely unknown. We report here the isolation of a novel basic helix-loop-helix protein, CjbHLH1, from IQA-producing Coptis japonica. A BLAST search indicated that CjbHLH1 homologs were only found in plant species that produce IQAs. Transient RNA interference (RNAi) and overexpression of CjbHLH1 in C. japonica protoplasts revealed the activity of CjbHLH1 in transcription of IQA biosynthetic genes, and little activity in the transcription of genes involved in primary metabolism or the stress response. A chromatin immunoprecipitation experiment using CjbHLH1-specific antibodies revealed the direct interaction of CjbHLH1 with promoter sequences of IQA biosynthetic genes in vivo. We discuss the unique role of CjbHLH1 in IQA biosynthesis.