Faitar Silviu L, Sossey-Alaoui Khalid, Ranalli Tamara A, Cowell John K
Department of Cancer Genetics, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY 14263, USA.
Exp Cell Res. 2006 Jul 15;312(12):2325-35. doi: 10.1016/j.yexcr.2006.03.032. Epub 2006 Apr 19.
EVI5 has been shown to be a novel centrosomal protein in interphase cells. In this report, we demonstrate using immunofluorescence microscopy that EVI5 has a dynamic distribution during mitosis, being associated with the mitotic spindle through anaphase and remaining within the midzone and midbody until completion of cytokinesis. Knockdown of EVI5 using siRNA results in a multinucleate phenotype, which is consistent with an essential role for this protein in the completion of cytokinesis. The EVI5 protein also undergoes posttranslational modifications during the cell cycle, which involve phosphorylation in early mitosis and proteolytic cleavage during late mitosis and cytokinesis. Since the subcellular distribution of the EVI5 protein was similar to that characteristic of chromosomal passenger proteins during the terminal stages of cytokinesis, we used immunoprecipitation and GST pull-down approaches to demonstrate that EVI5 is associated with the aurora B kinase protein complex (INCENP, aurora B kinase and survivin). Together, these data provide evidence that EVI5 is an essential component of the protein machinery facilitating the final stages of cell septation at the end of mitosis.
EVI5已被证明是间期细胞中一种新的中心体蛋白。在本报告中，我们使用免疫荧光显微镜证明，EVI5在有丝分裂期间具有动态分布，在后期与有丝分裂纺锤体相关，并在中带和中间体中保留至胞质分裂完成。使用小干扰RNA敲低EVI5会导致多核表型，这与该蛋白在胞质分裂完成中起重要作用一致。EVI5蛋白在细胞周期中也会发生翻译后修饰，包括在有丝分裂早期的磷酸化以及在有丝分裂后期和胞质分裂期间的蛋白水解切割。由于EVI5蛋白的亚细胞分布与胞质分裂末期染色体乘客蛋白的特征相似，我们使用免疫沉淀和GST下拉方法证明EVI5与极光B激酶蛋白复合物（INCENP、极光B激酶和survivin）相关。总之，这些数据提供了证据，表明EVI5是促进有丝分裂末期细胞分隔最后阶段的蛋白质机制的重要组成部分。
