GGA1 interacts with the adaptor protein AP-1 through a WNSF sequence in its hinge region
GGA1 interacts with the adaptor protein AP-1 through a WNSF sequence in its hinge region
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DOI：
10.1074/jbc.m401158200
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发表时间：
2004-04-23
影响因子：
4.8
通讯作者：
Kornfeld, S
中科院分区：
文献类型：
--
作者：
Bai, HD;Doray, B;Kornfeld, S
高尔基体相关的γ-适应素相关的ADP-核糖基化因子结合蛋白（GGA）是介导甘露糖6-磷酸受体和相关货物从高尔基体网络转运到内体的转运机制的关键组分。GGAs在体内与网格蛋白衔接蛋白AP-1共定位，并在体外与AP-1结合，表明这两种蛋白质可能在将甘露糖6-磷酸受体包装成网格蛋白包被的囊泡中合作。在这里，我们证明了序列，（WNSF 385）-W-382，在铰链区的GGA 1介导其与AP-1 γ-耳的相互作用。Trp和Phe构成这种相互作用中的关键氨基酸。Rabaptin 5与AP-1 γ-ear的结合（通过FXXPhi基序发生）被编码GGA 1（WNSF 385）-W-382序列的肽抑制。此外，AP-1 γ-ear中的突变消除了其与Rabaptin 5的相互作用，也排除了其与GGA 1的关联。这些结果表明，GGA 1 WXXF型和Rabaptin 5 FXXPhi型基序结合到AP-1 γ-耳中相同或高度重叠的位点。这种结合是由与核心基序相邻的残基调节的。
The Golgi-associated gamma-adaptin-related ADP-ribosylation factor-binding proteins (GGAs) are critical components of the transport machinery that mediates the trafficking of the mannose 6-phosphate receptors and associated cargo from the trans-Golgi network to the endosomes. The GGAs colocalize in vivo with the clathrin adaptor protein AP-1 and bind to AP-1 in vitro, suggesting that the two proteins may cooperate in packaging the mannose 6-phosphate receptors into clathrin-coated vesicles at the trans-Golgi network. Here, we demonstrate that the sequence, (WNSF385)-W-382, in the hinge region of GGA1 mediates its interaction with the AP-1 gamma-ear. The Trp and Phe constitute critical amino acids in this interaction. The binding of Rabaptin5 to the AP-1 gamma-ear, which occurs through a FXXPhi motif, is inhibited by a peptide encoding the GGA1 (WNSF385)-W-382 sequence. Moreover, mutations in the AP-1 gamma-ear that abolish its interaction with Rabaptin5 also preclude its association with GGA1. These results suggest that the GGA1 WXXF-type and Rabaptin5 FXXPhi-type motifs bind to the same or highly overlapping sites in the AP-1 gamma-ear. This binding is modulated by residues adjacent to the core motifs.