Endl E, Gerdes J
Department of Immunology and Cell Biology, Research Center Borstel, Borstel, D-23845, Germany.
Exp Cell Res. 2000 Jun 15;257(2):231-7. doi: 10.1006/excr.2000.4888.
The Ki-67 protein is a nuclear and nucleolar protein, which is tightly associated with somatic cell proliferation. Antibodies raised against the human Ki-67 protein paved the way for the immunohistological assessment of cell proliferation, particularly useful in numerous studies on the prognostic value of cell growth in clinical samples of human neoplasms. The primary structure revealed potential phosphorylation site for a range of essential kinases, PEST sequences, and a forkhead-associated domain, which are features present in a variety of cell-cycle-regulating proteins, but information about the position of the Ki-67 protein within the protein network that drives the cell cycle remained scarce. There is now evidence that posttranslational modifications based on phosphorylation by cdc2 kinase and PKC accompany the remarkable redistribution of the Ki-67 protein from the interior of the nucleus to the perichromosomal layer during mitosis and vice versa. The discovery of Ki-67 equivalents in other species is advantageous for a precise and cross-species investigation of the structural requirements for its yet unknown function. The recently published data add new pieces to the challenging puzzle of this multifaceted protein, which are waiting to be put together.
Ki-67蛋白是一种核蛋白和核仁蛋白，与体细胞增殖密切相关。针对人类Ki-67蛋白产生的抗体为细胞增殖的免疫组织学评估铺平了道路，这在众多关于人类肿瘤临床样本中细胞生长预后价值的研究中特别有用。其一级结构显示出一系列关键激酶的潜在磷酸化位点、PEST序列和一个叉头相关结构域，这些都是多种细胞周期调节蛋白所具有的特征，但关于Ki-67蛋白在驱动细胞周期的蛋白质网络中的位置信息仍然很少。现在有证据表明，在有丝分裂期间，基于细胞周期蛋白依赖性激酶2（cdc2激酶）和蛋白激酶C（PKC）磷酸化的翻译后修饰伴随着Ki-67蛋白从细胞核内部向染色体周围层的显著重新分布，反之亦然。在其他物种中发现Ki-67同源物有利于对其未知功能的结构要求进行精确的跨物种研究。最近发表的数据为这个多面蛋白的具有挑战性的谜题增添了新的内容，有待整合在一起。
