Spatiotemporal Dynamics of the BRI1 Receptor and its Regulation by Membrane Microdomains in Living Arabidopsis Cells
Spatiotemporal Dynamics of the BRI1 Receptor and its Regulation by Membrane Microdomains in Living Arabidopsis Cells
复制标题
拟南芥活细胞中 BRI1 受体的时空动态及其膜微区的调节
DOI：
10.1016/j.molp.2015.04.005
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发表时间：
2015-09-07
期刊：
影响因子：
27.5
通讯作者：
Lin, Jinxing
中科院分区：
文献类型：
--
作者：
Wang, Li;Li, Hong;Lin, Jinxing
拟南芥油菜素类固醇INSENSITIVE1(BRI1)的主要油菜素类固醇受体(BRI1)在BR信号转导中起重要作用，但BR影响BRI1内化和组装状态的分子机制尚不清楚。在这里，我们应用可变角度全内反射荧光显微镜和荧光互相关光谱来分析GFP标记的BRI1的动力学。我们发现，随着BR的响应，BRI1-GFP与AtFlot1-mCherry的共定位程度增加，特别是BR刺激了BRI1内化的膜微域相关途径。我们也在内吞缺陷chc2-1突变体和AtFlot1amiRNA15-5系中验证了这些观察到的结果。此外，对BRI1-EMS抑制因子1的磷酸化状态的检测和对BR反应基因表达的测量表明，膜微域影响BR信号转导。这些结果表明，BR促进BRI1分裂为功能膜微区，从而激活BR信号。
The major brassinosteroid (BR) receptor of Arabidopsis BRASSINOSTEROID INSENSITIVE1 (BRI1) plays fundamental roles in BR signaling, but the molecular mechanisms underlying the effects of BR on BRI1 internalization and assembly state remain unclear. Here, we applied variable angle total internal reflection fluorescence microscopy and fluorescence cross-correlation spectroscopy to analyze the dynamics of GFP-tagged BRI1. We found that, in response to BR, the degree of co-localization of BRI1-GFP with AtFlot1-mCherry increased, and especially BR stimulated the membrane microdomain-associated pathway of BRI1 internalization. We also verified these observations in endocytosis-defective chc2-1 mutants and the AtFlot1 amiRNA 15-5 lines. Furthermore, examination of the phosphorylation status of bri1-EMS-suppressor 1 and measurement of BR-responsive gene expression revealed that membrane microdomains affect BR signaling. These results suggest that BR promotes the partitioning of BRI1 into functional membrane microdomains to activate BR signaling.