Chromosome segregation in mitosis is orchestrated by the interaction of the kinetochore with spindle microtubules. Our recent study shows that NEK2A interacts with MAD 1 at the kinetochore and possibly functions as a ...Chromosome segregation in mitosis is orchestrated by the interaction of the kinetochore with spindle microtubules. Our recent study shows that NEK2A interacts with MAD 1 at the kinetochore and possibly functions as a novel integrator of spindle checkpoint signaling. However, it is unclear how NEK2A regulates kinetochore-microtubule attachment in mitosis. Here we show that NEK2A phosphorylates human Sgo 1 and such phosphorylation is essential for faithful chromosome congression in mitosis. NEK2A binds directly to HsSgol in vitro and co-distributes with HsSgol to the kinetochore of mitotic cells. Our in vitro phosphorylation experiment demonstrated that HsSgo 1 is a substrate of NEK2A and the phosphorylation sites were mapped to Ser^14 and Ser^507 as judged by the incorporation of 32^P. Although such phosphorylation is not required for assembly of HsSgo 1 to the kinetochore, expression of non-phosphorylatable mutant HsSgo 1 perturbed chromosome congression and resulted in a dramatic increase in microtubule attachment errors, including syntelic and monotelic attachments. These findings reveal a key role for the NEK2A-mediated phosphorylation ofHsSgo 1 in orchestrating dynamic kinetochore-microtubule interaction. We propose that NEK2A-mediated phosphorylation of human Sgo 1 provides a link between centromeric cohesion and spindle microtubule attachment at the kinetochores.展开更多
三阴性乳腺癌(triple-negative breast cancer,TNBC)的主要治疗方式是化疗,而化疗耐药是TNBC治疗的难点.发现在TNBC细胞系(MDA-MB-231、BT-549)中,Nek2A的表达异常增高,Nek2A-siRNA转染TNBC细胞系,降低Nek2A表达后,TNBC细胞增殖降低,化...三阴性乳腺癌(triple-negative breast cancer,TNBC)的主要治疗方式是化疗,而化疗耐药是TNBC治疗的难点.发现在TNBC细胞系(MDA-MB-231、BT-549)中,Nek2A的表达异常增高,Nek2A-siRNA转染TNBC细胞系,降低Nek2A表达后,TNBC细胞增殖降低,化疗药物联合Nek2A-siRNA组细胞增殖降低更明显.降低Nek2A表达可以增强紫杉醇及顺铂的化疗敏感性.检测裸鼠体内成瘤情况发现:Nek2A-siRNA联合紫杉醇(TAX)及顺铂(DDP)化疗药物组肿物最小.结果表明,Nek2A在TNBC中表达异常增高,并且降低Nek2A表达可以增强紫杉醇及顺铂化疗敏感性.展开更多
基金We thank members of our group for insightful discussion during the course of this study.This work was supported by grants from Chinese Academy of Science(KSCX1-YW-R65,KSCX2-YW-H10)National Basic Research Program of China(2002CB713700)+4 种基金Hi-Tech Research and Development Program of China(2001AA215331)Chinese Minister of Education(20020358051 to XY,PCSIRT0413 to XD)National Natural Science Foundation of China(39925018,30270293 to XY,30500183 to XD,30600222 to JY)National Institutes of Health(USA)(DK56292,CA92080)to XY(a Georgia Cancer Coalition Eminent Scholar)JY was supported by China Postdoctor(2005037560).
文摘Chromosome segregation in mitosis is orchestrated by the interaction of the kinetochore with spindle microtubules. Our recent study shows that NEK2A interacts with MAD 1 at the kinetochore and possibly functions as a novel integrator of spindle checkpoint signaling. However, it is unclear how NEK2A regulates kinetochore-microtubule attachment in mitosis. Here we show that NEK2A phosphorylates human Sgo 1 and such phosphorylation is essential for faithful chromosome congression in mitosis. NEK2A binds directly to HsSgol in vitro and co-distributes with HsSgol to the kinetochore of mitotic cells. Our in vitro phosphorylation experiment demonstrated that HsSgo 1 is a substrate of NEK2A and the phosphorylation sites were mapped to Ser^14 and Ser^507 as judged by the incorporation of 32^P. Although such phosphorylation is not required for assembly of HsSgo 1 to the kinetochore, expression of non-phosphorylatable mutant HsSgo 1 perturbed chromosome congression and resulted in a dramatic increase in microtubule attachment errors, including syntelic and monotelic attachments. These findings reveal a key role for the NEK2A-mediated phosphorylation ofHsSgo 1 in orchestrating dynamic kinetochore-microtubule interaction. We propose that NEK2A-mediated phosphorylation of human Sgo 1 provides a link between centromeric cohesion and spindle microtubule attachment at the kinetochores.
文摘三阴性乳腺癌(triple-negative breast cancer,TNBC)的主要治疗方式是化疗,而化疗耐药是TNBC治疗的难点.发现在TNBC细胞系(MDA-MB-231、BT-549)中,Nek2A的表达异常增高,Nek2A-siRNA转染TNBC细胞系,降低Nek2A表达后,TNBC细胞增殖降低,化疗药物联合Nek2A-siRNA组细胞增殖降低更明显.降低Nek2A表达可以增强紫杉醇及顺铂的化疗敏感性.检测裸鼠体内成瘤情况发现:Nek2A-siRNA联合紫杉醇(TAX)及顺铂(DDP)化疗药物组肿物最小.结果表明,Nek2A在TNBC中表达异常增高,并且降低Nek2A表达可以增强紫杉醇及顺铂化疗敏感性.
