The leucine-based sorting motifs in the cytoplasmic domain of the invariant chain are recognized by the clathrin adaptors AP1 and AP2 and their medium chains
The leucine-based sorting motifs in the cytoplasmic domain of the invariant chain are recognized by the clathrin adaptors AP1 and AP2 and their medium chains
复制标题
DOI：
10.1074/jbc.274.51.36153
复制
发表时间：
1999-12-17
影响因子：
4.8
通讯作者：
Bakke, O
中科院分区：
文献类型：
--
作者：
Hofmann, MW;Höning, S;Bakke, O
受体蛋白复合物对膜蛋白胞质尾部分选信号的识别是膜蛋白分选的关键步骤。已知的三种接头复合物AP1、AP2和AP3均可识别基于酪氨酸和亮氨酸的分选信号，这是膜蛋白细胞质尾部最常见的分选信号。尽管基于酪氨酸的分选信号可被接头复合物的μ链识别，但识别基于亮氨酸的分选信号的亚基尚不清楚。在本报告中，我们通过表面等离子体共振发现，在不变链的细胞质尾部，两个基于亮氨酸的分类信号相互独立地结合API和AP2，而不是AP3，我们还发现API和AP2的多链都可以识别这两个基序。此外，通过使用单体和三聚体不变链结构，我们发现适配器结合不需要三聚化不变链。
Recognition of sorting signals within the cytoplasmic tail of membrane proteins by adaptor protein complexes is a crucial step in membrane protein sorting. The three known adaptor complexes, AP1, AP2, and AP3, have all been shown to recognize tyrosine- and leucine-based sorting signals, which are the most common sorting signals within membrane protein cytoplasmic tails, Although tyrosine-based signals are recognized by the mu-chains of adaptor complexes, the subunit recognizing leucine-based sorting signals is less clear. In this report we show by surface plasmon resonance that the two leucine-based sorting signals within the cytoplasmic tail of the invariant chain bind independently from each other to API and AP2 but not to AP3, We also show that both motifs can be recognized by the mu-chains of API and AP2, Moreover, by using monomeric as well as trimeric invariant chain constructs, we show that adaptor binding does not require trimerization of the invariant chain.