Accurate chromosome segregation in mitosis depends on kinetochores that connect centromeric chromatin to spindle microtubules.Centromeres are captured by individual microtubules via a kinetochore constitutive centromere-associated network(CCAN)during chromosome segregation.CCAN contains 16 subunits,including CENP-W and CENP-T.However,the molecular recognition and mitotic regulation of the CCAN assembly remain elusive.Here,we revealed that CENP-W binds to the histone fold domain and an uncharacterized N-terminal region of CENP-T.Aurora B phosphorylates CENP-W at threonine 60,which enhances the interaction between CENP-W and CENP-T to ensure robust metaphase chromosome alignment and accurate chromosome segregation in mitosis.These findings delineate a conserved signaling cascade that integrates protein phosphorylation with CCAN integrity for the maintenance of genomic stability.
目的:分析着丝粒蛋白A(centromere protein A,CENP-A)在宫颈癌中的表达情况,与临床病理参数相关性及临床意义。方法:GEPIA和HPA数据库分析CENP-A基因及蛋白在宫颈癌组织中的表达情况;免疫组化检测宫颈癌中CENP-A蛋白的表达水平,分析其与临床病理参数之间的关系;使用Linked Omics数据库寻找与CENP-A共表达基因,分析CENP-A可能参与宫颈癌发生发展的信号通路。结果:生物信息学分析显示宫颈癌组织中CENP-A基因和蛋白的表达水平明显高于癌旁组织(P<0.05);免疫组化结果显示宫颈癌组织CENP-A蛋白表达水平显著高于癌旁组织(P<0.05),且与患者的肿瘤分期及浸润程度相关。通过基因共表达分析,KIF2C、CDC20、FAM72B等基因与CENP-A表达呈正相关,PARM1、ABCA9和SYNE1等基因与CENP-A表达呈负相关(FDR<0.05),CENP-A基因参与了细胞周期、DNA复制等途径。结论:CENP-A在宫颈癌组织中高表达,与宫颈癌的预后以及发生发展相关。
目的探讨CENP-A是否参与骨肉瘤细胞化疗耐药及与叉头框蛋白M1(forkhead box M1,FOXM1)的调控关系。方法采用Western blot法检测骨肉瘤亲本细胞(HOS、U2OS)、顺铂耐药细胞(HOS/R、U2OS/R)和稳定FOXM1过表达细胞(HOS/FOXM1、U2OS/FOXM1)中CENP-A蛋白表达。转染siRNA后检测CENP-A蛋白表达;运用CCK-8细胞增殖实验观察siRNA敲低CENP-A后耐药骨肉瘤细胞对顺铂敏感性的影响;FOXM1抑制剂RCM1处理后检测CENP-A蛋白表达。Kaplan-Meier法分析GEPIA数据库中CENP-A表达与患者预后的关系,Spearman相关性分析CENP-A和FOXM1两者之间的关系。结果骨肉瘤顺铂耐药细胞中CENP-A蛋白表达比亲本细胞明显升高(0.52±0.03 vs 0.92±0.01,0.33±0.02 vs 1.12±0.01),FOXM1过表达细胞中CENP-A表达较空载体对照亦明显增高;在骨肉瘤顺铂耐药和FOXM1过表达细胞中转染siRNA-CENP-A后,CENP-A蛋白表达均明显降低(0.84±0.01 vs 0.60±0.02,0.98±0.01 vs 0.41±0.01)。转染siRNA敲低CENP-A后,骨肉瘤耐药细胞和FOXM1过表达细胞对顺铂的耐药性明显降低。10μmol/L RCM1 FOXM1抑制剂处理耐药细胞和FOXM1过表达细胞后,CENP-A蛋白表达均明显下降。生物信息学分析发现CENP-A高表达组患者总生存期显著低于低表达组(P<0.01)。Spearman相关性分析发现CENP-A和FOXM1表达呈正相关(r=0.79)。结论FOXM1可能通过调控CENP-A参与骨肉瘤化疗耐药,为骨肉瘤化疗耐药治疗策略提供新的理论基础。
Shugoshin-1(Sgo1)is necessary for maintaining sister centromere cohesion and ensuring accurate chromosome segregation during mitosis.It has been reported that the localization of Sgo1 at the centromere is dependent on Bub1-mediated phosphorylation of histone H2A at T120.However,it remains uncertain whether other centromeric proteins play a role in regulating the localization and function of Sgo1 during mitosis.Here,we show that CENP-A interacts with Sgo1 and determines the localization of Sgo1 to the centromere during mitosis.Further biochemical characterization revealed that lysine and arginine residues in the C-terminal domain of Sgo1 are critical for binding CENP-A.Interestingly,the replacement of these basic amino acids with acidic amino acids perturbed the localization of Sgo1 and Aurora B to the centromere,resulting in aberrant chromosome segregation and premature chromatid separation.Taken together,these findings reveal a previously unrecognized but direct link between Sgo1 and CENP-A in centromere plasticity control and illustrate how the Sgo1–CENP-A interaction guides accurate cell division.
