Supervillin isoform 4(SV4)通过增强Aurora A活性调控细胞有丝分裂  

Supervillin Isoform 4(SV4)Regulates Mitosis by Enhancing Aurora A Activity

作　　者：毕文旭 张思钰 李抒洋 王薇[1] 陈学冉 方志友 BI Wen-Xu;ZHANG Si-Yu;LI Shu-Yang;WANG Wei;CHEN Xue-Ran;FANG Zhi-You(Institute of Health and Medical Technology,Hefei Institutes of Physical Science,Chinese Academy of Sciences,Hefei 230031,China;Basic Medical Science Research Center,Institute of Health and Medical Technology,Science Island Branch,Graduate School of University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]中国科学院合肥物质科学研究院健康与医学技术研究所,合肥230031 [2]中国科学技术大学研究生院科学岛分院健康与医学技术研究所基础医学中心,合肥230026

出　　处：《中国生物化学与分子生物学报》2023年第11期1588-1597,共10页Chinese Journal of Biochemistry and Molecular Biology

基　　金：国家自然科学基金项目(No.31571433;No.81773131)资助。

摘　　要：有丝分裂是真核生物进行细胞增殖的主要方式,染色体复制与准确分离对于有丝分裂的顺利进行至关重要。Supervillin是一种细胞膜与微丝肌动蛋白结合蛋白质,前期研究发现,其通过调控F-肌动蛋白、肌球蛋白II在细胞分裂过程中的皮层分布动态变化,从而保证肌动蛋白-肌动蛋白环组成收缩环并正确分布以及参与胞质分裂的最终完成,但不清楚在分裂中期是否有功能。Supervillin蛋白有多个剪接异构体,supervillin isoform 4(SV4)是其中分子量最大的一种剪接异构体。本研究利用RNA干扰方法敲低SV 4在细胞中的表达,通过实时显微成像、免疫荧光染色等技术,对细胞有丝分裂的动态进程及星极纺锤体形态进行了检测和观察,初步解析SV4调控细胞有丝分裂的潜在分子机制。结果显示,敲低SV 4后细胞分裂异常:细胞有丝分裂从中期到后期退出的时间出现延迟(P<0.001),由中心体介导的微管动态组装异常,以及出现多极纺锤体的细胞数量增多2倍,中心体内的γ-微管蛋白信号减少(P<0.001)等。通过GST pull down和质谱鉴定实验,发现SV4与Aurora A相互结合,SV4调节有丝分裂期间细胞中Aurora A在中心体的定位与活化。综上所述,supervillin蛋白在细胞有丝分裂进程中发挥着重要作用,异构体SV4在分裂中期,通过与Aurora A激酶的相互作用并募集其在中心体的正确定位与激活,从而调节纺锤体的完整性维持以及γ-微管蛋白的募集,促进双极纺锤体的微管正确组装,保证染色体的准确分离和有丝分裂的顺利进行。Mitosis is important for cell proliferation in eukaryotes,and chromosome replication and accurate separation are essential for cell division.Supervillin is a membrane and microfilament actin binding protein.Previous studies have found that it regulates the dynamic changes of the cortical distribution of F-actin and myosin II in cytokinesis,thus ensuring the correct distribution of the contraction ring and participating in the final completion of cytoplasm divisions.But it is not clear whether it functions during metaphase.Supervillin has several splicing isomers,among which supervillin isoform 4(SV4)is the largest splicing isomer.In this study,the expression of SV4 in cells was reduced by the RNA interference method,and the dynamic process of mitosis and the morphology of astral spindles were detected and observed by real-time microscopy and immunofluorescence staining,and the potential molecular mechanism of SV4 in mitosis was analyzed.The results showed abnormal cell divisions after SV4 reduction:delayed transition from metaphase to anaphase(P<0.001),abnormal assembly of microtubules,a twofold-increase of the number of cells with multipolar spindles,and decreasedγ-tubulin signaling in the centrosome(P<0.001).Through GST pull-down and mass spectrometry experiments,we found that SV4 and Aurora A bind to each other,and SV4 regulates the localization and activation of Aurora A in the centrosome during mitosis.In summary,supervillin plays an important role in mitosis.The isomer SV4 regulates spindle integrity andγ-tubulin recruitment by interacting with Aurora A and recruiting it for proper localization and activation in the centrosome during the metaphase,thus promoting the correct assembly of bipolar spindles and ensuring the accurate separation of chromosomes and the smooth progress of mitosis.

关 键 词：SUPERVILLIN Aurora A 中心体 有丝分裂 微管 

分 类 号：Q291[生物学—细胞生物学]