Phosphatidylinositol-(4,5)-bisphosphate regulates sorting signal recognition by the clathrin-associated adaptor complex AP2
Phosphatidylinositol-(4,5)-bisphosphate regulates sorting signal recognition by the clathrin-associated adaptor complex AP2
复制标题
DOI：
10.1016/j.molcel.2005.04.019
复制
发表时间：
2005-05-27
期刊：
影响因子：
16
通讯作者：
Owen, DJ
中科院分区：
文献类型：
--
作者：
Höning, S;Ricotta, D;Owen, DJ
α，β 2，μ 2，σ 2异四聚体AP 2复合物仅被募集到富含磷脂酰肌醇-4，5-二磷酸（PtdIns 4，5 P（2））的质膜，其中，除其他作用外，它选择含有基序的货物蛋白以掺入网格蛋白包被的囊泡中。产生了α PtdIns 4，5 P2、mu 2 PtdIns 4，5 P（2）和mu 2 Yxx phi结合位点突变的未磷酸化和mu 2 Thr 156-单磷酸化的AP 2，并通过表面等离子体共振测量了它们与不同磷脂和货物组成的膜的相互作用。我们证明，识别Yxx phi和酸性双亮氨酸基序是依赖于与PtdIns 4，5 P2的共识别，解释了选择性招聘的AP 2质膜。AP 2与PtdIns 4，5 P（2）/Yxx phi膜的相互作用分为两步：通过aPtdIns 4，5 P2位点的初始募集，然后通过mu 2 Yxx phi和mu 2 PtdIns 4，5 P2位点与其配体的结合而稳定。第二步是促进由mu 2 Thr 156磷酸化的构象变化。AP 2与酸性双亮氨酸基序的结合发生在与Yxx phi结合不同的位点，并且不被mu 2 Thr 156磷酸化增强。
The alpha,beta 2,mu 2,sigma 2 heterotetrameric AP2 complex is recruited exclusively to the phosphatidylinositol-4,5-bisphosphate (PtdIns4,5P(2))-rich plasma membrane where, amongst other roles, it selects motif-containing cargo proteins for incorporation into clathrin-coated vesicles. Unphosphorylated and mu 2Thr156-monophosphorylated AP2 mutated in their alpha PtdIns4,5P2, mu 2PtdIns4,5P(2), and mu 2Yxx phi binding sites were produced, and their interactions with membranes of different phospholipid and cargo composition were measured by surface plasmon resonance. We demonstrate that recognition of Yxx phi and acidic dileucine motifs is dependent on corecognition with PtdIns4,5P2, explaining the selective recruitment of AP2 to the plasma membrane. The interaction of AP2 with PtdIns4,5P(2)/Yxx phi-containing membranes is two step: initial recruitment via the aPtdIns4,5P2 site and then stabilization through the binding of mu 2Yxx phi and mu 2PtdIns4,5P2 sites to their ligands. The second step is facilitated by a conformational change favored by mu 2Thr156 phosphorylation. The binding of AP2 to acidic-dileucine motifs occurs at a different site from Yxx phi binding and is not enhanced by mu 2Thr156 phosphorylation.