Hinchcliffe E H, Li C, Thompson E A, Maller J L, Sluder G
Department of Cell Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
Science. 1999 Feb 5;283(5403):851-4. doi: 10.1126/science.283.5403.851.
The abnormally high number of centrosomes found in many human tumor cells can lead directly to aneuploidy and genomic instability through the formation of multipolar mitotic spindles. To facilitate investigation of the mechanisms that control centrosome reproduction, a frog egg extract arrested in S phase of the cell cycle that supported repeated assembly of daughter centrosomes was developed. Multiple rounds of centrosome reproduction were blocked by selective inactivation of cyclin-dependent kinase 2-cyclin E (Cdk2-E) and were restored by addition of purified Cdk2-E. Confocal immunomicroscopy revealed that cyclin E was localized at the centrosome. These results demonstrate that Cdk2-E activity is required for centrosome duplication during S phase and suggest a mechanism that could coordinate centrosome reproduction with cycles of DNA synthesis and mitosis.
在许多人类肿瘤细胞中发现的异常高数量的中心体，可通过形成多极有丝分裂纺锤体直接导致非整倍体和基因组不稳定。为了便于研究控制中心体复制的机制，开发了一种停滞在细胞周期S期的蛙卵提取物，该提取物支持子代中心体的重复组装。通过细胞周期蛋白依赖性激酶2-细胞周期蛋白E（Cdk2-E）的选择性失活，多轮中心体复制被阻断，并通过添加纯化的Cdk2-E得以恢复。共聚焦免疫显微镜显示细胞周期蛋白E定位于中心体。这些结果表明，Cdk2-E活性是S期中心体复制所必需的，并提示了一种可将中心体复制与DNA合成和有丝分裂周期相协调的机制。
