Orci L, Ravazzola M, Amherdt M, Perrelet A, Powell S K, Quinn D L, Moore H P
Institute of Histology and Embrology, University of Geneva, Switzerland.
Cell. 1987 Dec 24;51(6):1039-51. doi: 10.1016/0092-8674(87)90590-3.
The intracellular site for the sorting of proteins destined for regulated or constitutive pathways is presently unknown for any one cell. By immunoelectron microscopy, we directly followed the routes taken by a regulated hormone, insulin, and a constitutive protein, hemagglutinin. Both proteins are present in individual Golgi stacks where they appear randomly distributed throughout the cisternae. In contrast, the two proteins do not colocalize outside the Golgi area:insulin is concentrated in dense-core secretory granules, while hemagglutinin is found predominantly in clear 100-300 nm vesicles. These vesicles do not label significantly with an endocytic tracer, indicating that they are exocytic carriers for hemagglutinin. The site at which the two proteins diverge is the clathrin-coated, trans-most cisterna of the Golgi, where the packaging of proinsulin takes place.
目前，对于任何一个细胞而言，蛋白质分类进入调节性或组成性途径的细胞内位点都尚不清楚。通过免疫电子显微镜，我们直接追踪了一种调节性激素胰岛素和一种组成性蛋白血凝素所走的路径。这两种蛋白质都存在于单个高尔基体堆栈中，在那里它们似乎随机分布于整个潴泡中。相比之下，这两种蛋白质在高尔基体区域之外并不共定位：胰岛素集中在致密核心分泌颗粒中，而血凝素主要存在于100 - 300纳米的透明囊泡中。这些囊泡用内吞示踪剂标记不明显，表明它们是血凝素的胞吐载体。这两种蛋白质分离的位点是高尔基体网格蛋白包被的最外侧潴泡，胰岛素原在此进行包装。
