Real-time dynamics of peptide ligand-dependent receptor complex formation in planta
Real-time dynamics of peptide ligand-dependent receptor complex formation in planta
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DOI：
10.1126/scisignal.aab0598
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发表时间：
2015-08-04
影响因子：
7.3
通讯作者：
Simon, Ruediger
中科院分区：
文献类型：
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作者：
Somssich, Marc;Ma, Qijun;Simon, Ruediger
CLAVATA(CLV)和鞭毛蛋白(Flagellin，Flg)信号通路通过多肽配体和密切相关的质膜定位受体样激酶(RLKs)发挥作用。植物多肽CLV3调节干细胞的动态平衡，而细菌的flg22多肽则引起防御反应。我们应用多参数荧光成像光谱(MFIS)来表征在活体植物细胞中表达融合到荧光蛋白上的受体蛋白的配体存在下RLK复合体的动力学。我们发现，CLV和Flg通路代表了两种不同的信号转导原理：flg22首先触发RLK异源二聚，然后通过同聚组装成更大的复合体。相反，CLV受体复合体是预先形成的，配体结合刺激它们聚集。这种不同的行为可能反映了这些信号通路的性质。病原菌触发的Flg信号阻碍植物的生长发育，因此，只有在配体存在的情况下才能形成受体复合体。相反，依赖CLV3的干细胞动态平衡持续需要主动信号，而受体复合体的预形成可能有助于这一任务。
The CLAVATA (CLV) and flagellin (flg) signaling pathways act through peptide ligands and closely related plasma membrane-localized receptor-like kinases (RLKs). The plant peptide CLV3 regulates stem cell homeostasis, whereas the bacterial flg22 peptide elicits defense responses. We applied multiparameter fluorescence imaging spectroscopy (MFIS) to characterize the dynamics of RLK complexes in the presence of ligand in living plant cells expressing receptor proteins fused to fluorescent proteins. We found that the CLV and flg pathways represent two different principles of signal transduction: flg22 first triggered RLK heterodimerization and later assembly into larger complexes through homomerization. In contrast, CLV receptor complexes were preformed, and ligand binding stimulated their clustering. This different behavior likely reflects the nature of these signaling pathways. Pathogen-triggered flg signaling impedes plant growth and development; therefore, receptor complexes are formed only in the presence of ligand. In contrast, CLV3-dependent stem cell homeostasis continuously requires active signaling, and preformation of receptor complexes may facilitate this task.