Ochs R L, Lischwe M A, Spohn W H, Busch H
Biol Cell. 1985;54(2):123-33. doi: 10.1111/j.1768-322x.1985.tb00387.x.
Autoimmune serum from a patient with scleroderma was shown by indirect immunofluorescence to label nucleoli in a variety of cells tested including: rat kangaroo PtK2, Xenopus A6, 3T3, HeLa, and human peripheral blood lymphocytes. Immunoblot analysis of nucleolar proteins with the scleroderma antibody resulted in the labeling of a single protein band of 34 kD molecular weight with a pI of 8.5. Electron microscopic immunocytochemistry demonstrated that the protein recognized by the scleroderma antiserum was localized exclusively in the fibrillar region of the nucleolus which included both dense fibrillar and fibrillar center regions. Therefore, we have named this protein "fibrillarin". Fibrillarin was found on putative chromosomal nucleolar organizer regions (NORs) in metaphase and anaphase, and during telophase fibrillarin was found to be an early marker for the site of formation of the newly forming nucleolus. Double label indirect immunofluorescence and immunoelectron microscopy on normal, actinomycin D-segregated, and DRB-treated nucleoli showed that fibrillarin and nucleolar protein B23 were predominantly localized to the fibrillar and granular regions of the nucleolus, respectively. RNase A and DNase I digestion of cells in situ demonstrated that fibrillarin was partially removed by RNase and completely removed by DNase. These results suggest that fibrillarin is a widely occurring basic nonhistone nucleolar protein whose location and nuclease sensitivity may indicate some structural and/or functional role in the rDNA-containing dense fibrillar and fibrillar center regions of the nucleolus.
通过间接免疫荧光法显示，来自硬皮病患者的自身免疫血清可标记多种受试细胞中的核仁，这些细胞包括：大鼠袋鼠PtK2细胞、非洲爪蟾A6细胞、3T3细胞、HeLa细胞以及人外周血淋巴细胞。用硬皮病抗体对核仁蛋白进行免疫印迹分析，结果显示标记出一条分子量为34 kD、等电点为8.5的单一蛋白条带。电子显微镜免疫细胞化学表明，硬皮病抗血清识别的蛋白仅定位于核仁的纤维区，该区域包括致密纤维区和纤维中心区。因此，我们将这种蛋白命名为“纤维原蛋白”。在中期和后期，纤维原蛋白出现在假定的染色体核仁组织区（NORs）上，在末期，纤维原蛋白被发现是新形成核仁位点的早期标记物。对正常的、经放线菌素D分离的和经DRB处理的核仁进行双标记间接免疫荧光和免疫电子显微镜观察显示,纤维原蛋白和核仁蛋白B23分别主要定位于核仁的纤维区和颗粒区。原位对细胞进行核糖核酸酶A和脱氧核糖核酸酶I消化表明，纤维原蛋白可被核糖核酸酶部分去除，被脱氧核糖核酸酶完全去除。这些结果表明，纤维原蛋白是一种广泛存在的碱性非组蛋白核仁蛋白，其定位和核酸酶敏感性可能表明它在核仁中含核糖体DNA的致密纤维区和纤维中心区具有某些结构和/或功能作用。
