Arfaptins Are Localized to the trans-Golgi by Interaction with Arl1, but Not Arfs
Arfaptins Are Localized to the trans-Golgi by Interaction with Arl1, but Not Arfs
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DOI：
10.1074/jbc.m110.201442
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发表时间：
2011-04-01
影响因子：
4.8
通讯作者：
Shin, Hye-Won
中科院分区：
文献类型：
--
作者：
Man, Zhiqiu;Kondo, Yumika;Shin, Hye-Won
arfaptin （arfaptin-1和arfaptin-2/POR1）最初被确定为Arf小GTPases的结合伙伴。这两种蛋白都含有一个参与膜变形的BAR （Bin/Amphiphysin/Rvs）结构域。在这里，我们发现arfaptin与反式高尔基膜结合。出乎意料的是，Arl1 （arf样1）而不是Arfs决定了arfaptin的反式高尔基缔合。我们还证明了arfaptin通过其BAR结构域与Arl1相互作用，并竞争Arl1与golgin-97和golgin-245/p230的结合，两者也通过其GRIP （golgin-97/RanBP2/Imh1p/p230）结构域与Arl1结合。然而，arfaptin和这些高尔基蛋白仅在反式高尔基体上显示有限的共定位。过表达荧光蛋白标记的arfaptin和golgin-97的细胞延时成像显示，在高尔基区产生的囊泡和管状结构中包含arfaptin，而不是golgin-97。这些观察结果表明，arfaptin通过与Arl1的相互作用被招募到反式高尔基膜上，并能够通过其BAR结构域诱导膜变形。
Arfaptins (arfaptin-1 and arfaptin-2/POR1) were originally identified as binding partners of the Arf small GTPases. Both proteins contain a BAR (Bin/Amphiphysin/Rvs) domain, which participates in membrane deformation. Here we show that arfaptins associate with trans-Golgi membranes. Unexpectedly, Arl1 (Arf-like 1), but not Arfs, determines the trans-Golgi association of arfaptins. We also demonstrate that arfaptins interact with Arl1 through their BAR domain-containing region and compete for Arl1 binding with golgin-97 and golgin-245/p230, both of which also bind to Arl1 through their GRIP (golgin-97/RanBP2/Imh1p/p230) domains. However, arfaptins and these golgins show only limited colocalization at the trans-Golgi. Time-lapse imaging of cells overexpressing fluorescent protein-tagged arfaptins and golgin-97 reveals that arfaptins, but not golgin-97, are included in vesicular and tubular structures emanating from the Golgi region. These observations indicate that arfaptins are recruited onto trans-Golgi membranes by interacting with Arl1, and capable of inducing membrane deformation via their BAR domains.