Golgi stacks are the basic structural units of the Golgi. Golgi stacks are separated from each other and scattered in the cytoplasm of Drosophila cells. Here, we report that the ARF-GEF inhibitor Brefeldin A (BFA) induces the formation of BFA bodies, which are aggregates of Golgi stacks, trans-Golgi networks and recycling endosomes. Recycling endosomes are located in the centers of BFA bodies, while Golgi stacks surround them on their trans sides. Live imaging of S2 cells revealed that Golgi stacks repeatedly merged and separated on their trans sides, and BFA caused successive merger by inhibiting separation, forming BFA bodies. S2 cells carrying genome-edited BFA-resistant mutant Sec71^M717L did not form BFA bodies at high concentrations of BFA; S2 cells carrying genome-edited BFA-hypersensitive mutant Sec71^F713Y produced BFA bodies at low concentrations of BFA. These results indicate that Sec71 is the sole BFA target for BFA body formation and controls Golgi stack separation. Finally, we showed that impairment of Sec71 in fly photoreceptors induces BFA body formation, with accumulation of both apical and basolateral cargoes, resulting in inhibition of polarized transport.

高尔基体栈是高尔基体的基本结构单位。高尔基体堆叠彼此分离并分散在果蝇细胞的细胞质中。在此，我们报道 ARF-GEF 抑制剂 Brefeldin A (BFA) 诱导 BFA 体的形成，BFA 体是高尔基体堆栈、反式高尔基体网络和回收内体的聚集体。回收内体位于 BFA 体的中心，而高尔基体堆叠在其反面包围它们。S2细胞的实时成像显示，高尔基体堆叠在其反侧反复合并和分离，BFA通过抑制分离引起连续合并，形成BFA体。携带基因组编辑的BFA抗性突变体Sec71 ^M717L的S2细胞在高浓度BFA下不会形成BFA体；携带基因组编辑的 BFA 超敏突变体 Sec71 ^F713Y的 S2 细胞在低浓度的 BFA 下产生 BFA 体。这些结果表明 Sec71 是 BFA 体形成的唯一 BFA 靶标，并控制高尔基体堆叠分离。最后，我们发现果蝇光感受器中 Sec71 的损伤会诱导 BFA 体形成，并导致顶端和基底外侧货物的积累，从而抑制极化运输。