Constitutive activation of a nuclear-localized calcium channel complex in Medicago truncatula.
Constitutive activation of a nuclear-localized calcium channel complex in Medicago truncatula.
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DOI：
10.1073/pnas.2205920119
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发表时间：
2022-08-23
影响因子：
11.1
通讯作者：
中科院分区：
文献类型：
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作者：
Ca 2+是一种普遍存在的多功能第二信使，在真核生物的信号转导通路中起着重要作用。由Nod-或Myc-因子诱导的核/核周Ca ~（2+）振荡是豆科植物与根瘤菌和丛枝菌根真菌内共生的关键。核Ca 2+信号是如何产生的还知之甚少。我们已经在离子通道DMI 1中分离出了一个功能获得性突变，该突变诱导自发性钙振荡和自发性结节。使用结构生物学和遗传学，我们表明，打破DMI 1 RCK结构域的接口，导致通道被锁定在一个活跃的形式。用自激活的DMI 1和CNGC 15转染的HEK 293 T细胞显示自发通道活性。我们的工作提供了DMI 1和CNGC 15如何编码核Ca 2+振荡的见解。核Ca 2+振荡允许共生信号，促进植物识别有益的微共生体，固氮根瘤菌和营养捕获丛枝菌根真菌。两类通道，DMI 1和CNGC 15，在一个复杂的核膜上，协调共生Ca 2+振荡。然而，Ca 2+信号产生的机制是未知的。在这里，我们证明了这个通道复合物的自发激活，通过在DMI 1的功能获得突变，导致自发的核Ca 2+振荡和自发的钙离子，在CNGC 15依赖性的方式。突变使两个RCK结构域之间的氢键或盐桥网络不稳定，导致结构变化，以及DMI 1阳离子渗透性，激活通道复合物。该通道复合物在人HEK 293 T细胞系中重建，所产生的钙内流通过自激活的DMI 1和CNGC 15增强。我们的研究结果证明了这种核通道复合物的激活模式，表明DMI 1和CNGC 15足以产生振荡Ca 2+信号，并提供了对其天然诱导模式的见解。
Ca2+ represents a ubiquitous and versatile secondary messenger and plays important roles in signaling pathways in eukaryotic organisms. Nuclear/perinuclear Ca2+ oscillations induced by Nod- or Myc- factors are key in the endosymbioses of legume plants with rhizobial bacteria and arbuscular mycorrhizal fungi. How the nuclear Ca2+ signal is generated is poorly understood. We have isolated a gain-of-function mutation in the ion channel DMI1 that induces spontaneous calcium oscillations and spontaneous nodules. Using structural biology and genetics, we show that breaking the interface of DMI1 RCK domains results in the channel being locked in an active form. HEK293T cells transfected with autoactivated DMI1 and CNGC15s show spontaneous channel activity. Our work provides insights into how DMI1 and CNGC15 encode nuclear Ca2+ oscillations. Nuclear Ca2+ oscillations allow symbiosis signaling, facilitating plant recognition of beneficial microsymbionts, nitrogen-fixing rhizobia, and nutrient-capturing arbuscular mycorrhizal fungi. Two classes of channels, DMI1 and CNGC15, in a complex on the nuclear membrane, coordinate symbiotic Ca2+ oscillations. However, the mechanism of Ca2+ signature generation is unknown. Here, we demonstrate spontaneous activation of this channel complex, through gain-of-function mutations in DMI1, leading to spontaneous nuclear Ca2+ oscillations and spontaneous nodulation, in a CNGC15-dependent manner. The mutations destabilize a hydrogen-bond or salt-bridge network between two RCK domains, with the resultant structural changes, alongside DMI1 cation permeability, activating the channel complex. This channel complex was reconstituted in human HEK293T cell lines, with the resultant calcium influx enhanced by autoactivated DMI1 and CNGC15s. Our results demonstrate the mode of activation of this nuclear channel complex, show that DMI1 and CNGC15 are sufficient to create oscillatory Ca2+ signals, and provide insights into its native mode of induction.
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DOI：
10.1073/pnas.1107912108
发表时间：
2011-08-23
影响因子：
11.1
作者：
Capoen, Ward;Sun, Jongho;Oldroyd, Giles E. D.
通讯作者：
Oldroyd, Giles E. D.
DOI：
10.1107/s0907444904019158
发表时间：
2004-12-01
影响因子：
2.2
作者：
Emsley, P;Cowtan, K
通讯作者：
Cowtan, K
影响因子：
3.5
作者：
Edwards, Anne;Heckmann, Anne B.;Downie, J. Allan
通讯作者：
Downie, J. Allan
DOI：
10.1107/s0907444909052925
发表时间：
2010-02
期刊：
Acta crystallographica. Section D, Biological crystallography
影响因子：
--
作者：
Adams PD;Afonine PV;Bunkóczi G;Chen VB;Davis IW;Echols N;Headd JJ;Hung LW;Kapral GJ;Grosse-Kunstleve RW;McCoy AJ;Moriarty NW;Oeffner R;Read RJ;Richardson DC;Richardson JS;Terwilliger TC;Zwart PH
通讯作者：
Zwart PH
影响因子：
7.4
作者：
Engstrom, EM;Ehrhardt, DW;Long, SR
通讯作者：
Long, SR