一项新研究发现，细胞分裂增殖时一旦缺乏某种蛋白质将导致癌变。
美国普渡大学和中国四川大学的研究人员在10月刊《生物化学杂志》网络版上报告说，细胞质连接蛋白质170（CLIP－170）在细胞增殖及DNA（脱氧核糖核酸）分配方面起着主导作用，如果将这种蛋白质去除，在细胞增殖时就会失去完整的DNA复制功能，从而导致癌变。
研究人员解释说：“细胞增殖时，DNA必须要平均分配到子细胞中，如果子细胞与母细胞不一致，它们就会发生癌变。正常的细胞有非常严格的调节程序，以避免出现不平均分配，即所谓非整倍性现象。非整倍性现象是癌变的标志。”
据研究人员介绍，细胞分裂分两步：一是复制自己的DNA，并制造出两个中央体，它们可以像磁铁一样吸附住DNA；当中央体吸附住DNA后，细胞便开始分裂，这一过程被称为有丝分裂，会制造出两个相同的细胞。
然而，将CLIP－170从细胞中剔除后，形成的中央体会超过两个，将DNA拉向几个不同的方向，因此每一中央体都不能吸附一个完整的DNA。这时，细胞便产生混乱，发生癌变等。（生物谷Bioon.com）
生物谷推荐原始出处：
JBC August 17, 2009, doi: 10.1074/jbc.M109.017681
CDC2-mediated phosphorylation of clip-170 is essential for its inhibition of centrosome reduplication
Xiaoming Yang1, Hongchang Li2, Anping Deng1 and Xiaoqi Liu2,*
1 Sichuan University, China;
2 Purdue University, United States
CLIP-170, the founding member of microtubule plus ends tracking proteins, is involved in many critical microtubule-related functions, including recruitment of dynactin to the microtubule plus ends, and formation of kinetochore-microtubule attachments during metaphase. Although it has been reported that CLIP-170 is a phosphoprotein, neither have individual phosphorylation sites been identified nor have the associated kinases been extensively studied. Herein, we identify Cdc2 as a kinase that phosphorylates CLIP-170. We show that Cdc2 interacts with CLIP-170 mediating its phosphorylation on Thr287 in vivo. Significantly, expression of CLIP-170 with a threonine 287 to alanine substitution (T287A) results in its mis-localization, accumulation of Plk1 and cyclin B, and block of the G2/M transition. Finally, we found that depletion of CLIP-170 leads to centrosome reduplication and that Cdc2 phosphorylation of CLIP-170 is required for the process. These results demonstrate that Cdc2-mediated phosphorylation of CLIP-170 is essential for the normal function of this protein during cell cycle progression.
