Barrowman J, Sacher M, Ferro-Novick S
Howard Hughes Medical Institute, Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06519, USA.
EMBO J. 2000 Mar 1;19(5):862-9. doi: 10.1093/emboj/19.5.862.
Bet3p, a component of a large novel complex called TRAPP, acts upstream of endoplasmic reticulum (ER)-Golgi SNAREs. Unlike the SNAREs, which reside on multiple compartments, Bet3p is localized exclusively to Golgi membranes. While other proteins recycle from the Golgi to the ER, Bet3p and other TRAPP subunits remain associated with this membrane under conditions that block anterograde traffic. We propose that the persistent localization of TRAPP to the Golgi may be important for its role in docking vesicles to this membrane. Consistent with this proposal, we find that transport vesicles fail to bind to Golgi membranes in vitro in the absence of Bet3p. Binding is restored by the addition of cytosol containing Bet3p. These findings indicate that TRAPP stably associates with the Golgi and is required for vesicle docking.
Bet3p是一种名为TRAPP的大型新型复合物的组成部分,在内质网(ER)-高尔基体SNARE蛋白的上游发挥作用。与存在于多个区室的SNARE蛋白不同,Bet3p仅定位于高尔基体膜。当其他蛋白质从高尔基体循环回到内质网时,在阻断顺行运输的条件下,Bet3p和其他TRAPP亚基仍与该膜相关联。我们提出,TRAPP持续定位于高尔基体可能对其在将囊泡对接至该膜的过程中所起的作用很重要。与这一观点一致,我们发现在体外没有Bet3p的情况下,运输囊泡无法与高尔基体膜结合。添加含有Bet3p的胞质溶胶可恢复结合。这些发现表明,TRAPP与高尔基体稳定结合,并且是囊泡对接所必需的。