Role of the ENTH domain in phosphatidylinositol-4,5-bisphosphate binding and endocytosis
Role of the ENTH domain in phosphatidylinositol-4,5-bisphosphate binding and endocytosis
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DOI：
10.1126/science.291.5506.1047
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发表时间：
2001-02-09
期刊：
影响因子：
56.9
通讯作者：
Takenawa, T
中科院分区：
文献类型：
--
作者：
Itoh, T;Koshiba, S;Takenawa, T
内吞蛋白如epsin、AP 180和Hip 1 R（SLa 2 p）共享称为epsin NH 2-末端同源（ENTH）结构域的保守模块化区域，其通过未知靶标在网格蛋白介导的内吞中起关键作用。在这里，我们证明了ENTH结构域对磷脂酰肌醇-4，5-二磷酸[Ptdlns（4，5）P-2]的强亲和力。通过对胰蛋白酶ENTH结构域的核磁共振分析，我们确定了带正电荷的残基形成的裂缝有助于磷酸肌醇结合。突变体epsin Lys（76）→ Ala（76）的过表达，具有磷酸肌醇结合缺陷的ENTH结构域，阻断了COS-7细胞中表皮生长因子的内化。因此，ENTH结构域和Ptdlns（4，5）P-2之间的相互作用对于网格蛋白包被的小凹介导的内吞作用是必需的。
Endocytic proteins such as epsin, AP180, and Hip1R (SLa2p) share a conserved modular region termed the epsin NH2-terminal homology (ENTH) domain, which plays a crucial role in clathrin-mediated endocytosis through an unknown target. Here, we demonstrate a strong affinity of the ENTH domain for phosphatidylinositol-4,5-bisphosphate [Ptdlns(4,5)P-2]. With nuclear magnetic resonance analysis of the epsin ENTH domain, we determined that a cleft formed with positively charged residues contributed to phosphoinositide binding. Overexpression of a mutant, epsin Lys(76) --> Ala(76), with an ENTH domain defective in phosphoinositide binding, blocked epidermal growth factor internalization in COS-7 cells. Thus, interaction between the ENTH domain and Ptdlns(4,5)P-2 is essential for endocytosis mediated by clathrin-coated pits.