Cerdido A, Medina F J
Centro de Investigaciones Biológicas (CSIC), Madrid, Spain.
Chromosoma. 1995 May;103(9):625-34. doi: 10.1007/BF00357689.
The nucleolar protein fibrillarin has been studied in onion cells; it is detected as an M(r) 37,000 protein by immunoblotting using a human autoimmune serum. Quantitative immunoelectron microscopy showed that most fibrillarin is localized in the transition zone between the fibrillar center (FC) and the dense fibrillar component (DFC) as well as in the proximal zone of the DFC, where the labeling shows a gradual decrease outward until it reaches insignificant levels in the distal zone of the DFC. Thus, fibrillarin is not uniformly distributed throughout the DFC of plant cells. This result supports the hypothesis that the morphologically homogeneous DFC may not be uniform in function; it is also in agreement with the hypothesized vectorial flow of ribosome biogenesis through the same compartments. Data are also presented showing that the amount of fibrillarin increases when nucleolar activity increases in G2, and probably decreases when nucleolar activity decreases during differentiation.
已在洋葱细胞中对核仁蛋白原纤维蛋白进行了研究；使用人自身免疫血清通过免疫印迹法将其检测为一种分子量为37,000的蛋白质。定量免疫电子显微镜显示，大多数原纤维蛋白定位于纤维中心（FC）和致密纤维组分（DFC）之间的过渡区以及DFC的近端区域，在该区域标记显示向外逐渐减少，直至在DFC的远端区域达到微不足道的水平。因此，原纤维蛋白并非均匀分布于植物细胞的整个DFC中。这一结果支持了形态上均一的DFC在功能上可能并不均匀的假说；这也与核糖体生物发生通过相同区室的假定向量流相一致。还呈现的数据表明，当核仁活性在G2期增加时，原纤维蛋白的量增加，而在分化过程中当核仁活性降低时，原纤维蛋白的量可能减少。
