The specificity of membrane traffic involves tethers at destination organelles that selectively capture incoming transport vesicles to allow SNAREs on opposing membranes to then assemble and drive fusion. Tethers include both protein complexes and long coiled-coil proteins, although how they contribute to specificity remains unclear. The golgin coiled-coil proteins at the Golgi apparatus capture vesicles from different origins, but the vesicle-specific molecular cues that they recognize are unknown. Vesicle tethering is typically a transient process and therefore is challenging to interrogate in vivo. Thus, we have used a system in which an ectopic golgin causes vesicles to accumulate in a tethered state. By applying proximity biotinylation to the golgin-captured vesicles, we identify TBC1D23, an apparently catalytically inactive member of a family of Rab GTPase-activating proteins (GAPs), as a vesicle-golgin adaptor that is required for endosome-to-Golgi trafficking. The Rab GAP domain of TBC1D23 binds to a conserved motif at the tip of golgin-245 and golgin-97 at the trans-Golgi, while the C terminus binds to the WASH complex on endosome-derived vesicles. Thus, TBC1D23 is a specificity determinant that links the vesicle to the target membrane during endosome-to-Golgi trafficking.

中文翻译：

---

TBC1D23 是 golgins 在跨高尔基体捕获内体囊泡的桥接因子。

膜运输的特异性涉及目标细胞器的系绳，该系绳选择性地捕获传入的运输囊泡，以允许相对膜上的 SNARE 然后组装并驱动融合。系链包括蛋白质复合物和长卷曲螺旋蛋白，尽管它们如何促进特异性仍不清楚。高尔基体中的高尔金卷曲螺旋蛋白捕获来自不同来源的囊泡，但它们识别的囊泡特异性分子线索是未知的。囊泡束缚通常是一个短暂的过程，因此在体内进行审讯具有挑战性。因此，我们使用了一个系统，其中异位高尔金导致囊泡在束缚状态下积聚。通过对高尔金捕获的囊泡应用邻近生物素化，我们识别了 TBC1D23，Rab GTP 酶激活蛋白 (GAP) 家族中明显无催化活性的成员，作为内体到高尔基体运输所需的囊泡-高尔金接头。TBC1D23 的 Rab GAP 结构域与高尔基体 golgin-245 和 golgin-97 末端的保守基序结合，而 C 末端与内体衍生囊泡上的 WASH 复合物结合。因此，TBC1D23 是在内体到高尔基体运输过程中将囊泡与靶膜连接的特异性决定因素。