NECAP2 controls clathrin coat recruitment to early endosomes for fast endocytic recycling
NECAP2 controls clathrin coat recruitment to early endosomes for fast endocytic recycling
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DOI：
10.1242/jcs.173708
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发表时间：
2016-07-01
影响因子：
4
通讯作者：
Ritter, Brigitte
中科院分区：
文献类型：
--
作者：
Chamberland, John P.;Antonow, Lauren T.;Ritter, Brigitte
内吞再循环将受体内化后返回质膜，对于维持细胞表面的受体水平、使细胞对细胞外配体重新敏感以及持续营养吸收至关重要。然而，驱动内吞再循环的蛋白质机器和机制仍然不明确。在这里，我们确定 NECAP2 调节 EGFR 和转铁蛋白受体的内吞再循环。我们对回收动力学的分析表明，NECAP2 在快速回收途径中发挥作用，将货物从早期内体直接返回到细胞表面。相反，NECAP2 不调节网格蛋白介导的这些货物的内吞作用、EGFR 的降解或转铁蛋白沿着缓慢的、Rab11 依赖性回收途径的回收。我们发现 NECAP2 的蛋白质敲低会导致早期内涵体增大，并导致细胞器中网格蛋白接头 AP-1 的丢失。通过结构功能分析，我们定义了 NECAP2 中的蛋白质结合界面，这对于 AP-1 募集到早期内体至关重要。总之，我们的数据确定 NECAP2 是早期内体上网格蛋白涂层形成的通路特异性调节剂，以实现快速内吞循环。
Endocytic recycling returns receptors to the plasma membrane following internalization and is essential to maintain receptor levels on the cell surface, re-sensitize cells to extracellular ligands and for continued nutrient uptake. Yet, the protein machineries and mechanisms that drive endocytic recycling remain ill-defined. Here, we establish that NECAP2 regulates the endocytic recycling of EGFR and transferrin receptor. Our analysis of the recycling dynamics revealed that NECAP2 functions in the fast recycling pathway that directly returns cargo from early endosomes to the cell surface. In contrast, NECAP2 does not regulate the clathrin-mediated endocytosis of these cargos, the degradation of EGFR or the recycling of transferrin along the slow, Rab11-dependent recycling pathway. We show that protein knockdown of NECAP2 leads to enlarged early endosomes and causes the loss of the clathrin adapter AP-1 from the organelle. Through structure-function analysis, we define the protein-binding interfaces in NECAP2 that are crucial for AP-1 recruitment to early endosomes. Together, our data identify NECAP2 as a pathway-specific regulator of clathrin coat formation on early endosomes for fast endocytic recycling.