Celis J E, Celis A
Proc Natl Acad Sci U S A. 1985 May;82(10):3262-6. doi: 10.1073/pnas.82.10.3262.
Immunofluorescence analysis of synchronously growing transformed human amnion cells (AMA) using autoantibodies specific for cyclin has revealed dramatic changes in the nuclear distribution of this protein during the S phase of the cell cycle. Cells in G1, G2, and mitosis exhibit weak staining with the antibody, while S-phase cells show variable patterns of staining in terms of both intensity and distribution of the antigen. Early in S phase, cyclin is localized throughout the nucleoplasm with the exception of the nucleoli. A similar, but stronger, staining pattern is observed as the cells progress through the S phase. At a later stage, before maximum DNA synthesis, cyclin redistributes to reveal a punctuated pattern with foci of staining throughout the nucleus. This pattern precedes a major change in the distribution of this protein, which is then detected in the nucleolus. At this stage, DNA synthesis is at or near a maximum. Thereafter, there are further changes in the distribution of this protein, with the pattern becoming punctuated and of decreasing intensity. All these staining patterns have also been detected in asynchronously growing normal human amnion cells (AF type), suggesting that the distribution of this protein is not a consequence of transformation. Analysis of cultured cells from several vertebrate species also revealed similar staining patterns. These results are consistent with the idea that cyclin is a central component of the pathway(s) leading to DNA replication and cell division.
使用细胞周期蛋白特异性自身抗体对同步生长的转化人羊膜细胞（AMA）进行免疫荧光分析，结果显示在细胞周期的S期，该蛋白的核分布发生了显著变化。处于G1期、G2期和有丝分裂期的细胞与抗体的染色较弱，而S期细胞在抗原强度和分布方面呈现出不同的染色模式。在S期早期，细胞周期蛋白除核仁外遍布整个核质。随着细胞进入S期，观察到类似但更强的染色模式。在后期，在DNA合成达到最大值之前，细胞周期蛋白重新分布，呈现出整个细胞核内有染色焦点的点状模式。这种模式先于该蛋白分布的重大变化，随后在核仁中检测到这种变化。此时，DNA合成达到或接近最大值。此后，该蛋白的分布进一步变化，模式变为点状且强度降低。在异步生长的正常人羊膜细胞（AF型）中也检测到了所有这些染色模式，这表明该蛋白的分布不是转化的结果。对几种脊椎动物物种培养细胞的分析也显示出类似的染色模式。这些结果与细胞周期蛋白是导致DNA复制和细胞分裂途径的核心成分这一观点一致。
