Clathrin binding by the adaptor Ent5 promotes late stages of clathrin coat maturation.
Clathrin binding by the adaptor Ent5 promotes late stages of clathrin coat maturation.
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DOI：
10.1091/mbc.e15-08-0588
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发表时间：
2016-04-01
影响因子：
3.3
通讯作者：
Duncan MC
中科院分区：
文献类型：
--
作者：
Hung CW;Duncan MC
网格蛋白衔接子将货物连接到网格蛋白外壳。网格蛋白适配器Ent 5也是在trans-Golgi网络或内体处的网格蛋白外套成熟所必需的，这表明它在外套形成中起关键的机械作用。该功能仅需要Ent 5网格蛋白结合位点，而不需要其与其他内体衔接子的相互作用。网格蛋白是一种普遍存在的蛋白质，其在许多位置介导膜运输。为了发挥作用，网格蛋白需要将其连接到跨膜蛋白货物的网格蛋白衔接子。除了这种货物选择功能之外，许多适配器还在运输载体的形成中发挥机械作用。然而，对这些机械作用的全部谱知之甚少。在这里，我们报告说，Ent 5，在酿酒酵母内体网格蛋白适配器，调节网格蛋白外套的行为后，招募网格蛋白。我们发现，Ent 5的丢失破坏了网格蛋白依赖的交通，并延长了含有网格蛋白和其他适配器的内体结构的寿命，这表明在后期阶段的外套成熟缺陷。我们发现，直接绑定的Ent 5与网格蛋白是必需的，其作用在大衣的行为和货物运输。令人惊讶的是，Ent 5与其他适配器的相互作用是为皮毛行为而不是货物运输。这些发现支持了一种模型，其中Ent 5网格蛋白结合在外套成熟中起机械作用，而Ent 5衔接子结合促进货物掺入。
Clathrin adaptors link cargo to the clathrin coat. The clathrin adaptor Ent5 is also required for the maturation of clathrin coats at the trans-Golgi network or endosome, suggesting that it plays a key mechanistic role in coat formation. This function requires only the Ent5 clathrin-binding sites and not its interaction with other endosomal adaptors. Clathrin is a ubiquitous protein that mediates membrane traffic at many locations. To function, clathrin requires clathrin adaptors that link it to transmembrane protein cargo. In addition to this cargo selection function, many adaptors also play mechanistic roles in the formation of the transport carrier. However, the full spectrum of these mechanistic roles is poorly understood. Here we report that Ent5, an endosomal clathrin adaptor in Saccharomyces cerevisiae, regulates the behavior of clathrin coats after the recruitment of clathrin. We show that loss of Ent5 disrupts clathrin-dependent traffic and prolongs the lifespan of endosomal structures that contain clathrin and other adaptors, suggesting a defect in coat maturation at a late stage. We find that the direct binding of Ent5 with clathrin is required for its role in coat behavior and cargo traffic. Surprisingly, the interaction of Ent5 with other adaptors is dispensable for coat behavior but not cargo traffic. These findings support a model in which Ent5 clathrin binding performs a mechanistic role in coat maturation, whereas Ent5 adaptor binding promotes cargo incorporation.