zur Nieden U, Manteuffel R, Weber E, Neumann D
Eur J Cell Biol. 1984 May;34(1):9-17.
The main storage globulins of Vicia faba seeds, vicilin and legumin, were localized in ultrathin sections of developing cotyledons employing the protein A/colloidal gold-technique. Double labelling experiments with monospecific immunoglobulins directed against vicilin or legumin using different size classes of protein A-colloidal gold showed that both globulins are associated with protein lumps in the vacuoles of early developmental stages of the seeds and with the rough endoplasmic reticulum, the site of storage protein biosynthesis. Furthermore, vicilin and legumin have been detected in protein-containing vesicles in the cytoplasm as well as in dictyosomes and the dictyosome-derived vesicles. The association of storage globulins with the dictyosomes was also indicated by cell fractionation and immunoblotting of organelle contents derived from microsome, enriched dictyosome and protein body preparations. Protein blotting analyses employing a Concanavalin A/peroxidase technique showed that certain vicilin polypeptides were already glycosylated in the rough endoplasmic reticulum. Another part of the vicilin fraction as well as legumin polypeptides did not show any affinity to Concanavalin A. These data provide a direct evidence for a transient involvement of dictyosomes in the intracellular pathway of legume storage globulins from the rough endoplasmic reticulum to their accumulation site in the protein bodies.
利用蛋白A/胶体金技术，在蚕豆种子发育子叶的超薄切片中定位了蚕豆种子的主要贮藏球蛋白——豌豆球蛋白和豆球蛋白。使用不同大小的蛋白A-胶体金对针对豌豆球蛋白或豆球蛋白的单特异性免疫球蛋白进行双标记实验表明，这两种球蛋白都与种子早期发育阶段液泡中的蛋白块以及贮藏蛋白生物合成场所粗面内质网有关。此外，在细胞质中的含蛋白质小泡以及高尔基体和源自高尔基体的小泡中也检测到了豌豆球蛋白和豆球蛋白。细胞分级分离以及对源自微粒体、富集高尔基体和蛋白体制剂的细胞器内容物进行免疫印迹，也表明贮藏球蛋白与高尔基体有关。采用伴刀豆球蛋白A/过氧化物酶技术的蛋白质印迹分析表明，某些豌豆球蛋白多肽在粗面内质网中已经被糖基化。豌豆球蛋白组分的另一部分以及豆球蛋白多肽对伴刀豆球蛋白A没有任何亲和力。这些数据直接证明了高尔基体短暂参与了豆科植物贮藏球蛋白从粗面内质网到其在蛋白体中积累位点的细胞内途径。
