A MYB coiled-coil transcription factor interacts with NSP2 and is involved in nodulation in Lotus japonicus
A MYB coiled-coil transcription factor interacts with NSP2 and is involved in nodulation in Lotus japonicus
复制标题
MYB 卷曲螺旋转录因子与 NSP2 相互作用并参与百脉根的结瘤。
DOI：
10.1111/nph.12593
复制
发表时间：
2014-02-01
期刊：
影响因子：
9.4
通讯作者：
Zhang, Zhongming
中科院分区：
文献类型：
--
作者：
Kang, Heng;Chu, Xiaojie;Zhang, Zhongming
转录因子复合体的形成是调控基因表达的中心步骤。本文报道了一种新的与NSP2蛋白相互作用的MYB螺旋螺旋转录因子IPN2，并通过蛋白质下拉实验和双分子荧光互补(BIFC)检测了IPN2与NSP2之间的相互作用。对分别表达标签重组蛋白、启动子-报告基因和RNA干扰(RNAi)结构的转基因毛状根中蛋白质的亚细胞定位、基因表达和基因功能进行了研究，发现NSP2的Gras结构域和IPN2的卷曲线圈结构域负责这两种蛋白之间的相互作用。IPN2具有很强的转录激活活性，直接与NIN基因启动子结合，定位于莲花根细胞的细胞核。IPN2在根瘤发育过程中表达增强，与NSP2基因在根瘤器官发生过程中表达增强相一致。RNAi介导的IPN2基因的敲除表达不影响丛枝菌根的发育，但对根瘤菌的侵染和根瘤的形成有不利影响。这些结果证明了IPN2在根瘤器官发生中的重要作用，并将一个新的MYB转录因子置于NOD信号通路中。
Transcription factor complex formation is a central step in regulating gene expression. In this report, a novel MYB coiled-coil transcription factor referred to as IPN2, for Interacting Protein of NSP2, is described.The interaction between IPN2 and NSP2 was examined by protein pull-down assays and bimolecular fluorescence complementation (BiFC). Subcellular localization of proteins, gene expression and gene function were assessed in transgenic hairy roots expressing tagged recombinant proteins, promoter-reporter and RNA interference (RNAi) constructs, respectively.The GRAS domain of NSP2 and the coiled-coil domain of IPN2 were found to be responsible for the interaction between the two proteins. IPN2 had strong transcription activation activity, bound directly to the NIN gene promoter, and was localized to the nuclei of Lotus japonicus root cells. The expression of IPN2 was elevated during nodule development, coinciding with increased NSP2 gene expression during nodule organogenesis. RNAi-mediated knockdown expression of IPN2 did not affect arbuscular mycorrhizal development, but had deleterious effects on rhizobial infection and nodule formation in L. japonicus.These results demonstrate an important role of IPN2 in nodule organogenesis and place a new MYB transcription factor in the Nod signaling pathway.