Autoantigen golorin-97, an effector of Arl1 GTPase, participates in traffic from the endosome to the Trans-golgi network
Autoantigen golorin-97, an effector of Arl1 GTPase, participates in traffic from the endosome to the Trans-golgi network
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DOI：
10.1091/mbc.e03-12-0872
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发表时间：
2004-10-01
影响因子：
3.3
通讯作者：
Hong, WJ
中科院分区：
文献类型：
--
作者：
Lu, L;Tai, GH;Hong, WJ
Arl 1及其效应物GRIP结构域Golgins的精确细胞功能尚未解决，尽管我们最近了解到Arl 1调节这些Golgins的膜募集。在这份报告中，我们描述了我们的功能研究Golgin-97。利用基于滋贺毒素B片段（STx B）的体外转运试验，我们证明了Golgin-97在从内体转运到trans-Golgi网络（TGN）中起作用。Golgin-97的重组GRIP结构域以及针对Golgin-97的抗体在体外抑制STxB的转运。在体外转运试验中需要膜相关Golgin-97，而不是其胞质池。与抗突触融合蛋白16抗体相比，抗Golgin-97抗体的抑制动力学特征确定了Golgin-97在内体至TGN的转运中先于突触融合蛋白16发挥作用。通过它们各自的小干扰RNA（siRNA）敲低Golgin-97或Arl 1也显著抑制STxB向体内高尔基体的转运。在Arl 1水平降低的siRNA处理的细胞中，内化的STxB反而分布在外周。显微注射Golgin-97抗体可使高尔基体断裂，并阻止内化的霍乱毒素B片段转运至高尔基体。我们认为Golgin-97可能在内体-TGN逆行交通中起拴系分子的作用。
The precise cellular function of Arl1 and its effectors, the GRIP domain Golgins, is not resolved, despite our recent understanding that Arl1 regulates the membrane recruitment of these Golgins. In this report, we describe our functional study of Golgin-97. Using a Shiga toxin B fragment (STxB)-based in vitro transport assay, we demonstrated that Golgin-97 plays a role in transport from the endosome to the trans-Golgi network (TGN). The recombinant GRIP domain of Golgin-97 as well as antibodies against Golgin-97 inhibited the transport of STxB in vitro. Membrane-associated Golgin-97, but not its cytosolic pool, was required in the in vitro transport assay. The kinetic characterization of inhibition by anti-Golgin-97 antibody in comparison with anti-Syntaxin 16 antibody established that Golgin-97 acts before Syntaxin 16 in endosome-to-TGN transport. Knock down of Golgin-97 or Arl1 by their respective small interference RNAs (siRNAs) also significantly inhibited the transport of STxB to the Golgi in vivo. In siRNA-treated cells with reduced levels of Arl1, internalized STxB was instead distributed peripherally. Microinjection of Golgin-97 antibody led to the fragmentation of Golgi apparatus and the arrested transport to the Golgi of internalized Cholera toxin B fragment. We suggest that Golgin-97 may function as a tethering molecule in endosome-to-TGN retrograde traffic.