Akimoto Y, Obinata A, Endo H, Furukawa K, Aoki D, Nozawa S, Hirano H
Department of Anatomy, Kyorin University School of Medicine, Tokyo, Japan.
Anat Rec. 1995 Sep;243(1):109-19. doi: 10.1002/ar.1092430113.
beta-1, 4-Galactosyltransferase (GalTase) transfers galactose from UDP-galactose to terminal N-acetylglucosamine in glycoconjugates and is located both in the Golgi apparatus and in the plasma membrane. The cell surface GalTase is thought to be involved in cell-to-cell recognition and cell-to-extracellular matrix interaction.
By the use of specific monoclonal antibodies against human GalTase, changes in cell surface localization of the protein reactive to the antibodies in chick embryonic skin during its differentiation in vivo and in vitro were detected immunohistochemically at both light- and electron microscopic levels. The distribution of glycoconjugates having terminal N-acetylglucosamine residues was detected by staining with succinylated wheat germ agglutinin (s-WGA).
Under the light microscope, intense immunostaining was observed in the keratinized epidermis, particularly in the intermediate layer. Marked changes in the localization of the staining were observed in vitamin A-induced mucus-secreting skin, in which keratinization was suppressed. The localization of the immunostaining was in parallel with that of glycoconjugates having terminal N-acetylglucosamine residues. Immunoelectron microscopically the immunostaining was located on the cell surface and in the intercellular space of the desmosomes in the intermediate cells of the keratinized epidermis. However, the staining was not present on the cell surface but was detected on the limiting membrane of the mucous granules, in the mucous metaplastic epidermis. In contrast, the staining was always found in the Golgi apparatus in all of the cells.
These results suggest that the protein reactive to human GalTase antibody may be involved in chick epidermal differentiation.
β-1,4-半乳糖基转移酶（GalTase）将来自尿苷二磷酸半乳糖的半乳糖转移至糖缀合物末端的N-乙酰葡糖胺，且位于高尔基体和质膜中。细胞表面的GalTase被认为参与细胞间识别和细胞与细胞外基质的相互作用。
通过使用针对人GalTase的特异性单克隆抗体，在光镜和电镜水平上免疫组织化学检测鸡胚皮肤在体内和体外分化过程中对该抗体有反应的蛋白质在细胞表面定位的变化。用琥珀酰化麦胚凝集素（s-WGA）染色检测具有末端N-乙酰葡糖胺残基的糖缀合物的分布。
在光镜下，在角化表皮中观察到强烈的免疫染色，特别是在中间层。在维生素A诱导的黏液分泌皮肤中观察到染色定位的明显变化，其中角化受到抑制。免疫染色的定位与具有末端N-乙酰葡糖胺残基的糖缀合物的定位平行。免疫电镜下，免疫染色位于角化表皮中间细胞的细胞表面和桥粒的细胞间隙中。然而，在黏液化生表皮中，染色不在细胞表面，而是在黏液颗粒的界膜上检测到。相反，在所有细胞的高尔基体中总是能发现染色。
这些结果表明，对人GalTase抗体有反应的蛋白质可能参与鸡表皮分化。
