Importance of glycoproteins in the initiation of melanogenesis: an electron microscopic study of B-16 melanoma cells after release from inhibition of glycosylation.
Importance of glycoproteins in the initiation of melanogenesis: an electron microscopic study of B-16 melanoma cells after release from inhibition of glycosylation.
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糖蛋白在黑色素生成启动中的重要性：B-16 黑色素瘤细胞从糖基化抑制中释放后的电子显微镜研究。
DOI：
10.1111/1523-1747.ep12524388
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发表时间：
1986
期刊：
影响因子：
--
通讯作者：
Yutaka Mishima
中科院分区：
文献类型：
--
作者：
G. Imokawa;Yutaka Mishima
研究发现，对核心碳水化合物合成的特异性抑制会导致黑素小体的选择性异常和黑色素丢失，并伴随着功能糖蛋白酪氨酸酶中的碳水化合物部分的改变。为了进一步阐明糖蛋白在启动黑化过程中的生物学意义，对糖基化抑制剂诱导的黑素合成中断后恢复期的初始黑素合成进行了电子显微镜研究。也用电子细胞化学方法研究了相应的黑素生成亚细胞室的酪氨酸酶活性的变化。将B-16黑色素瘤细胞暴露于抑制剂培养10-20天后，解除糖基化抑制，使其黑化消失。48h后黑素化开始明显恢复，72h基本恢复到正常水平。在电子显微镜水平上，去除氨基葡萄糖48h后，黑素小体内可见周期性的黑素小体基质重新形成，随后72h内可见明显的黑色素颗粒沿其周期性沉积。在衣霉素实验中，黑素小体内的黑化是在细丝状内部的浓度变得不那么明显之后，随着微泡在内部的多重聚集而开始的。电子显微镜下的多巴反应显示，溶酶体和包被囊泡的高尔基相关内质网中的多巴黑色素的沉积一直持续到24小时。此后，多巴黑色素在前黑素小体中的主要定位逐渐增加，最终变得几乎一致。这些观察提示了糖基化参与黑素合成的两种可能机制：第一，酪氨酸酶的转位可能受特定碳水化合物部分的存在调节；第二，黑素体基质蛋白含有碳水化合物，在形成颗粒结合的T3酪氨酸酶后，可能有助于酪氨酸酶的接受酪氨酸酶功能或在体内的黑化功能。
Specific inhibition of core carbohydrate synthesis has been found to induce selective aberration and melanin loss in melanosomes, accompanied by alteration of the carbohydrate moiety in functioning glycoproteins, tyrosinases. In order to further clarify the biologic significance of glycoproteins in the initiation of melanization, initial melanogenesis which occurs during the recovery period following interrupted melanogenesis induced by glycosylation inhibitors, has been electron microscopically investigated. Changes in the tyrosinase activity of the corresponding melanogenic subcellular compartments have also been studied electron cytochemically. Removal of glycosylation inhibition was carried out after exposure of B-16 melanotic melanoma cells to the inhibitors for 10-20 culture days resulting in the loss of their melanization. Recovery of melanization begins visibly 48 h later, thereafter almost attaining the previous normal level by 72 h. At the electron microscopic level, re-formation of melanosomal matrix with periodicity is observed within premelanosomes 48 h after removal of glucosamine, soon followed by deposition of apparent melanin particles along their periodicity by 72 h. In tunicamycin experiments, melanization within premelanosomes starts after the concentration of the fine threadlike interior becomes less distinct followed by a prominence of multiple accumulation of microvesicles within the interior. Electron microscopic dopa reaction shows that the deposition of dopa melanin is prominent in Golgi-associated endoplasmic reticulum of lysosome and coated vesicles up to 24 h after the removal. Thereafter, predominant localization of dopa melanin in premelanosomes gradually increases and finally becomes almost uniform. These observations suggest 2 possible mechanisms for the involvement of glycosylation in melanogenesis: first, the translocation of tyrosinases may be regulated by the presence of specific carbohydrate moieties; second, melanosomal matrix proteins contain carbohydrates which may contribute to the tyrosinase-accepting function or in vivo melanizing function of tyrosinases after forming particle-bound T3 tyrosinase.
广泛性显性单纯性大疱性表皮松解症：作为表型标记的培养成纤维细胞中明胶分解蛋白酶的活性降低。
DOI：
10.1111/1523-1747.ep12523269
发表时间：
1983
期刊：
The Journal of investigative dermatology
影响因子：
--
作者：
Sanchez,G;Seltzer,JL;Eisen,AZ;Stapler,P;Bauer,EA
通讯作者：
Bauer,EA
电子显微镜和细胞化学观察茶碱和黑素细胞刺激激素对培养的黑色素瘤细胞的影响。
影响因子：
11.2
作者：
Hu,F;Mah,K;Teramura,DJ
通讯作者：
Teramura,DJ