Taatjes D J, Roth J, Shaper N L, Shaper J H
Department of Pathology, University of Vermont, Burlington 05405.
Glycobiology. 1992 Dec;2(6):579-89. doi: 10.1093/glycob/2.6.579.
Post-embedding immunocytochemistry was employed to investigate the distribution of UDP-galactose:N-acetylglucosamine galactosyltransferase (beta 1,4-GT) in epithelial cells from various bovine organs. Several well characterized monoclonal antibodies previously demonstrated to recognize distinct polypeptide epitopes within the primary structure of beta 1,4-GT were applied to thin sections from tissues embedded in Lowicryl K4M, followed by the protein A-gold technique. Immunoreactivity was observed in the Golgi apparatus of epithelial cells from intestine, thymus and trachea. No immunoreactivity was observed in other intracellular structures, including rough endoplasmic reticulum, nuclear envelope and goblet cell mucus droplets. Within the Golgi apparatus, the staining was restricted to several cisternae in the trans region, with most portions of the trans-Golgi network appearing unlabelled. However, in thymic epithelial-reticular cells trans-Golgi network portions resembling classical GERL elements were stained by the antibodies. Thus, although immunoreactivity was subcompartmentalized within the Golgi apparatus in all epithelial cell types examined, the extent of staining within the trans-Golgi network was variable. Immunoreactivity was not detected at the plasma membrane (ecto-galactosyl-transferase), except in the case of a subpopulation of tracheal cells that resemble brush cells. These results suggest that in the epithelial cells examined, the subcompartmental distribution of beta 1,4-GT within the Golgi apparatus is maintained across different types of epithelial cell organization. Moreover, no evidence for a general epithelial cell ecto-galactosyltransferase could be discerned with these reagents.
采用包埋后免疫细胞化学方法研究UDP-半乳糖：N-乙酰葡糖胺半乳糖基转移酶（β1,4-GT）在牛不同器官上皮细胞中的分布。应用几种先前已充分表征的单克隆抗体，这些抗体能识别β1,4-GT一级结构内不同的多肽表位，将其应用于包埋在Lowicryl K4M中的组织薄片，随后采用蛋白A-金技术。在肠、胸腺和气管上皮细胞的高尔基体中观察到免疫反应性。在其他细胞内结构中未观察到免疫反应性，包括粗面内质网、核膜和杯状细胞黏液滴。在高尔基体中，染色局限于反式区域的几个扁平囊，反式高尔基体网络的大部分未被标记。然而，在胸腺上皮网状细胞中，类似经典GERL元件的反式高尔基体网络部分被抗体染色。因此，尽管在所检查的所有上皮细胞类型中，免疫反应性在高尔基体中是亚区室化的，但反式高尔基体网络内的染色程度是可变的。除了类似于刷细胞的气管细胞亚群外，在质膜（胞外半乳糖基转移酶）未检测到免疫反应性。这些结果表明，在所检查的上皮细胞中，β1,4-GT在高尔基体中的亚区室分布在不同类型的上皮细胞组织中得以维持。此外，用这些试剂未发现普遍存在的上皮细胞质膜外半乳糖基转移酶的证据。
