Single Particle Tracking Reveals that EGFR Signaling Activity Is Amplified in Clathrin-Coated Pits
Single Particle Tracking Reveals that EGFR Signaling Activity Is Amplified in Clathrin-Coated Pits
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DOI：
10.1371/journal.pone.0143162
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发表时间：
2015-11-17
期刊：
影响因子：
3.7
通讯作者：
Verveer, Peter J.
中科院分区：
文献类型：
--
作者：
Ibach, Jenny;Radon, Yvonne;Verveer, Peter J.
表皮生长因子受体（EGFR）通过其C-末端酪氨酸残基上的磷酸化的信号传导需要自缔合，这取决于受体的扩散性质及其在质膜中的密度。二聚化是EGFR激活的关键事件，但高阶聚类的作用尚不清楚。我们采用单粒子追踪将EGFR的迁移和聚集与其信号传导活性联系起来。EGFR的移动性在短暂的自由、受限和不动状态之间交替。在不动状态下，EGFR倾向于聚集在网格蛋白包被的凹坑中，其以磷酸化依赖性方式进一步增强，并且不需要配体结合。EGFR磷酸化通过网格蛋白包被的小凹中的交叉磷酸化进一步放大。因为磷酸化受体可以从凹坑中逃逸，所以形成了信号传导活性EGFR的局部梯度。这些结果表明，通过网格蛋白包被的小凹中的受体聚集的EGFR磷酸化的放大支持质膜处的信号激活。
Signaling from the epidermal growth factor receptor (EGFR) via phosphorylation on its C-terminal tyrosine residues requires self-association, which depends on the diffusional properties of the receptor and its density in the plasma membrane. Dimerization is a key event for EGFR activation, but the role of higher order clustering is unknown. We employed single particle tracking to relate the mobility and aggregation of EGFR to its signaling activity. EGFR mobility alternates between short-lived free, confined and immobile states. In the immobile state, EGFR tends to aggregate in clathrin-coated pits, which is further enhanced in a phosphorylation-dependent manner and does not require ligand binding. EGFR phosphorylation is further amplified by cross-phosphorylation in clathrin-coated pits. Because phosphorylated receptors can escape from the pits, local gradients of signaling active EGFR are formed. These results show that amplification of EGFR phosphorylation by receptor clustering in clathrin-coated pits supports signal activation at the plasma membrane.