School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom.
Traffic. 2011 Nov;12(11):1552-62. doi: 10.1111/j.1600-0854.2011.01258.x. Epub 2011 Aug 24.
We screened a panel of compounds derived from Exo2 - a drug that perturbs post-Golgi compartments and trafficking in mammalian cells - for their effect on the secretory pathway in Arabidopsis root epidermal cells. While Exo2 and most related compounds had no significant effect, one Exo2 derivative, named LG8, induced severe morphological alterations in both the Golgi (at high concentrations) and the endoplasmic reticulum (ER). LG8 causes the ER to form foci of interconnecting tubules, which at the ultrastructural level appear similar to those previously reported in Arabidopsis roots after treatment with the herbicide oryzalin. In cotyledonary leaves, LG8 causes redistribution of a trans Golgi network (TGN) marker to the vacuole. LG8 affects the anterograde secretory pathway by inducing secretion of vacuolar cargo and preventing the brassinosteroid receptor BRI1 from reaching the plasma membrane. Uptake and arrival at the TGN of the endocytic marker FM4-64 is not affected. Unlike the ADP ribosylation factor-GTP exchange factor (ARF-GEF) inhibitor brefeldin A (BFA), LG8 affects these post-Golgi events without causing the formation of BFA bodies. Up to concentrations of 50 µm, the effects of LG8 are reversible.
我们筛选了一组源自 Exo2 的化合物，这些化合物可以干扰哺乳动物细胞的高尔基体后区室和运输过程，以研究它们对拟南芥根表皮细胞分泌途径的影响。虽然 Exo2 和大多数相关化合物没有显著影响，但一种名为 LG8 的 Exo2 衍生物在高尔基体（高浓度时）和内质网（ER）中均诱导严重的形态改变。LG8 导致 ER 形成相互连接的小管焦点，在超微结构水平上，这些焦点与 previously reported 在拟南芥根中用除草剂 oryzalin 处理后类似。在子叶中，LG8 将跨高尔基体网络（TGN）标记物重新分配到液泡中。LG8 通过诱导液泡货物的分泌并阻止油菜素内酯受体 BRI1 到达质膜，从而影响正向分泌途径。内吞标记物 FM4-64 的摄取和到达 TGN 不受影响。与 ADP 核糖基化因子-GTP 交换因子（ARF-GEF）抑制剂布雷菲德菌素 A（BFA）不同，LG8 影响这些高尔基体后事件，而不会形成 BFA 体。在高达 50 µm 的浓度下，LG8 的作用是可逆的。
