Identification of a novel nuclear domain.
Identification of a novel nuclear domain.
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DOI：
10.1083/jcb.112.5.785
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发表时间：
1991-03
期刊：
影响因子：
--
通讯作者：
Maul GG
中科院分区：
文献类型：
--
作者：
Ascoli CA;Maul GG
对于大多数已知的核结构域（ND），其特定功能已被确定。在本报告中，我们使用鼠单克隆抗体和人自身抗体来研究直径为0.2 - 0.3微米的精确限定结构，这些结构呈现为分布在整个核质中的“核点”。核点在代谢上是稳定的，并且对核酸酶消化和盐提取具有抗性。核点的定位与动粒、着丝粒、mRNA加工位点和tRNA合成位点、核体以及染色体是分开的。因此，核点代表一种新的核结构域。当细胞进入中期时核点分解，在末期重新组装。在间期细胞中，核点经常“成对”，并且当用一种特定抗血清染色时，一些核点可见为“双联体”。当静止细胞受到血清刺激时，双联体核点的数量增加，尽管核点的总数没有实质性变化。其中一种抗原被鉴定为一种分子量约为55kD的蛋白质，在等电点（pI）7.4至7.7范围内呈现三种电荷异构体。从这种核点蛋白（NDP - 55）亲和纯化的自身抗体仅显示核点。核点阴性的大鼠肝实质细胞在化学肝切除术后变为阳性，这表明NDP - 55参与细胞的增殖状态。
For most known nuclear domains (ND), specific functions have been identified. In this report we used murine mAbs and human autoantibodies to investigate precisely circumscribed structures 0.2-0.3 micron in diameter which appear as "nuclear dots" distributed throughout the nucleoplasm. Nuclear dots are metabolically stable and resistant to nuclease digestion and salt extraction. The localization of nuclear dots is separate from kinetochores, centromeres, sites of mRNA processing and tRNA synthesis, nuclear bodies, and chromosomes. The nuclear dots, therefore, represent a novel ND. Nuclear dots break down as cells enter metaphase and reassemble at telophase. In interphase cells, nuclear dots are frequently "paired," and some are visible as "doublets" when stained with one particular antiserum. The number of dot doublets increased when quiescent cells were stimulated with serum although the total number of dots did not change substantially. One of the antigens was identified as a protein with a molecular mass of approximately 55 kD showing three charge isomers in the pI range of 7.4 to 7.7. Autoantibodies affinity purified from this nuclear dot protein (NDP-55) show nuclear dots exclusively. Nuclear dot-negative rat liver parenchymal cells became positive after chemical hepatectomy, suggesting involvement of the NDP-55 in the proliferative state of cells.