Mechanism of phosphate sensing and signaling revealed by rice SPX1-PHR2 complex structure.
Mechanism of phosphate sensing and signaling revealed by rice SPX1-PHR2 complex structure.
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水稻SPX1-PHR2复合体结构揭示的磷酸盐传感和信号转导机制
DOI：
10.1038/s41467-021-27391-5
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发表时间：
2021-12-02
影响因子：
16.6
通讯作者：
Xing W
中科院分区：
文献类型：
--
作者：
Zhou J;Hu Q;Xiao X;Yao D;Ge S;Ye J;Li H;Cai R;Liu R;Meng F;Wang C;Zhu JK;Lei M;Xing W
磷是一种关键的植物营养物质，通过含有SPX结构域的蛋白通过肌醇多聚磷酸盐(INSPs)来感知。SPX1 AN抑制PHR2转录因子，维持PI内环境平衡。SPX1如何识别Insp分子并抑制PHR2的转录激活尚不清楚。在这里，我们表明，与InsP6结合后，SPX1可以破坏PHR2二聚体，形成1：1的SPX1-PHR2复合体。复杂的结构表明，SPX1螺旋α1在与PHR2二聚体相互作用时可以施加空间位阻。通过稳定螺旋α1，InsP6变构解偶联PHR2二聚体，稳定SPX1-PHR2相互作用。在这样做的过程中，InsP6进一步允许SPX1与PHR2 MYB结构域结合，并立体地阻止其与DNA的相互作用。综上所述，我们的结果表明，在感应到磷酸盐的替代信号后，SPX1通过双重机制抑制PHR2，从而减弱PHR2的二聚化和DNA结合活性。SPX蛋白通过与肌醇多磷酸(InSP)结合并抑制PHR转录因子的活性来感知植物细胞中的磷酸盐水平。在这里，作者表明，当与InsP6结合时，水稻SPX1蛋白通过减弱其二聚化和DNA结合活性来抑制PHR2的活性。
Phosphate, a key plant nutrient, is perceived through inositol polyphosphates (InsPs) by SPX domain-containing proteins. SPX1 an inhibit the PHR2 transcription factor to maintain Pi homeostasis. How SPX1 recognizes an InsP molecule and represses transcription activation by PHR2 remains unclear. Here we show that, upon binding InsP6, SPX1 can disrupt PHR2 dimers and form a 1:1 SPX1-PHR2 complex. The complex structure reveals that SPX1 helix α1 can impose a steric hindrance when interacting with the PHR2 dimer. By stabilizing helix α1, InsP6 allosterically decouples the PHR2 dimer and stabilizes the SPX1-PHR2 interaction. In doing so, InsP6 further allows SPX1 to engage with the PHR2 MYB domain and sterically block its interaction with DNA. Taken together, our results suggest that, upon sensing the surrogate signals of phosphate, SPX1 inhibits PHR2 via a dual mechanism that attenuates dimerization and DNA binding activities of PHR2. SPX proteins sense phosphate levels in plant cells by binding to inositol polyphosphates (InsP) and suppressing the activity of PHR transcription factors. Here the authors show that when bound to InsP6, the rice SPX1 protein inhibits the activity of PHR2 by attenuating both its dimerization and DNA binding activity.
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影响因子：
56.9
作者：
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通讯作者：
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影响因子：
16.8
作者：
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影响因子：
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影响因子：
1.6
作者：
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通讯作者：
DODSON, AN
DOI：
10.1073/pnas.1404680111
发表时间：
2014-10-14
影响因子：
11.1
作者：
Wang, Zhiye;Ruan, Wenyuan;Wu, Ping
通讯作者：
Wu, Ping