College of Chemistry, Sichuan University, Chengdu 610064, China.
Mol Biol Rep. 2010 Jul;37(6):3023-8. doi: 10.1007/s11033-009-9871-1. Epub 2009 Oct 11.
Topors is a DNA topoisomerase I- and p53-binding protein, and mainly functions as a p53 regulator. Accumulating evidence also supports the notion that Topors plays the role as a negative regulator of cell growth, and possibly as a tumor suppressor. Here, we demonstrated that Topors is also involved in normal mitotic progression, since Topors depletion delays mitotic entry and affects mitotic progression. Furthermore, Topors is degradated in response to the activation of the spindle checkpoint. Significantly, Polo-like kinase 1 (Plk1)-associated phosphorylation of Topors at S718 is essential for nocodazole-induced degradation of Topors.
拓扑异构酶 I 和 p53 结合蛋白 Topors 主要作为 p53 调节因子发挥作用。越来越多的证据也支持这样一种观点，即 Topors 作为细胞生长的负调节剂发挥作用，并可能作为肿瘤抑制因子发挥作用。在这里，我们证明 Topors 也参与正常有丝分裂进程，因为 Topors 耗竭延迟有丝分裂进入并影响有丝分裂进程。此外，Topors 响应纺锤体检查点的激活而降解。重要的是，Polo 样激酶 1（Plk1）相关的 Topors 的 S718 磷酸化对于诺考达唑诱导的 Topors 降解是必需的。
