纺锤体检验点(spindle checkpoint)是一个重要的细胞分裂生化调节通路,可监督染色体正确分离和传代.着丝粒相关蛋白E(centromere-associated protein E,CENP-E)是一个分子量为312kD的微管马达驱动蛋白,可以衔接纺锤体微管与动点并参与...纺锤体检验点(spindle checkpoint)是一个重要的细胞分裂生化调节通路,可监督染色体正确分离和传代.着丝粒相关蛋白E(centromere-associated protein E,CENP-E)是一个分子量为312kD的微管马达驱动蛋白,可以衔接纺锤体微管与动点并参与纺锤体检验点调控.为研究CENP-E的作用机理,以其动点结合区域为诱饵蛋白,用酵母双杂交技术从人HeLa细胞cDNA文库中筛选出了Nuf2蛋白.体外的pull-down实验和体内的免疫共沉淀实验表明,Nuf2蛋白通过其卷曲螺旋(coiled-coil)功能域特异结合CENP-E的C末端区域,间接免疫荧光显示Nuf2与CENP-E共定位于细胞有丝分裂期染色体的动点.由此推论,CENP-E通过Nuf2的直接作用参与构筑动点-微管界面,进而参与细胞有丝分裂纺锤体检验点信号转导通路,为染色体正确分离发挥调控作用.展开更多
本文以HeLa细胞为材料研究一种着丝粒蛋白CENP-B的基因表达与细胞周期及细胞核骨架的关系。将HeLa细胞同步在不同周期时相,以流式细胞光度术、同位素掺入和ACA着丝粒染色等方法检测细胞同步化效果。我们分别提取了各周期时相细胞的总RNA...本文以HeLa细胞为材料研究一种着丝粒蛋白CENP-B的基因表达与细胞周期及细胞核骨架的关系。将HeLa细胞同步在不同周期时相,以流式细胞光度术、同位素掺入和ACA着丝粒染色等方法检测细胞同步化效果。我们分别提取了各周期时相细胞的总RNA和Poly(A)^+RNA,用Dot blot和Northern blot杂交方法研究CENP-B在细胞周期中的表达。结果表明,CENP-B基因在细胞周期中的各个时相均有表达,但表达的强度差别很大:G2期表达最强,S期最弱,G1期中的表达介于二者之间;有意义的是CENP-B基因在M期仍然有较强的表达,表现出其在细胞周期中表达的持续性;这种表达的持续性反映了一种可能性:着丝粒、动粒蛋白不断合成,但直到S期后进入G2期时着丝粒、动粒蛋白到一定临界浓度时才开始组装新的动粒。另外,着丝粒、动粒蛋白的持续合成对着丝粒、动粒功能的发挥可能是必需的。用Bam H I限制性内切酶消化处于不同细胞周期时相的HeLa细胞核骨架,提取与核骨架紧密结合的DNA,用^(32)P标记的cDNA为探针研究CENP-B基因与细胞核骨架的结合与其表达的关系。结果证明,在G2期细胞中CENP-B基因表达最强,与细胞核骨架结合最为紧密,G1期细胞中次之,S期中CENP-B基因与核骨架结合最弱,说明CENP-B基因与细胞核骨架结合的紧密度影响其表达强度。展开更多
目的探讨CENP-A表达在人类胚胎绒毛染色体分离中的作用。方法应用荧光原位杂交(fluorescence in situ hybridization,FISH)技术检测94例自然流产胚胎绒毛染色体数目,分别用q RT-PCR和Western blotting检测胚胎绒毛组织中CENP-A m RNA和...目的探讨CENP-A表达在人类胚胎绒毛染色体分离中的作用。方法应用荧光原位杂交(fluorescence in situ hybridization,FISH)技术检测94例自然流产胚胎绒毛染色体数目,分别用q RT-PCR和Western blotting检测胚胎绒毛组织中CENP-A m RNA和蛋白质相对表达水平。结果 194例自然流产胚胎中检出异常结果病例数共48例,占总病例数的51.06%,其中阳性病例数30例,阳性率为31.91%。比较常见的异常类型有16三体、21三体、22三体、X单体和三倍体。2CENP-A m RNA在实验组和对照组表达水平差异无统计学意义(P>0.05)。3异常组胚胎绒毛组织中CENP-A蛋白相对表达水平明显高于正常组,差异具有统计学意义(P<0.05)。结论着丝粒蛋白CENP-A表达异常与染色体非整倍体引起的自然流产有关。展开更多
Mitosin/CENP-F is a human nuclear protein transiently associated with the outer kinetochore plate in M phase and is involved in M phase progression. LEK1 and CMF1, which are its murine and chicken orthologs, however, ...Mitosin/CENP-F is a human nuclear protein transiently associated with the outer kinetochore plate in M phase and is involved in M phase progression. LEK1 and CMF1, which are its murine and chicken orthologs, however, are implicated in muscle differentiation and reportedly not distributed at kinetochores.We therefore conducted several assays to clarify this issue. The typical centromere staining patterns were observed in mitotic cells from both human primary culture and murine, canine, and mink cell lines. A C-terminal portion of LEK1 also conferred centromere localization. Our analysis further suggests conserved kinetochore localization of mammalian mitosin orthologs. Moreover, mitosin was associated preferentially with kinetochores of unaligned chromosomes. It was also constantly transported from kinetochores to spindle poles by cytoplasmic dynein. These properties resemble those of other kinetochore proteins important for the spindle checkpoint, thus implying a role of mitosin in this checkpoint. Therefore, mitosin family may serve as multifunctional proteins involved in both mitosis and differentiation.展开更多
文摘纺锤体检验点(spindle checkpoint)是一个重要的细胞分裂生化调节通路,可监督染色体正确分离和传代.着丝粒相关蛋白E(centromere-associated protein E,CENP-E)是一个分子量为312kD的微管马达驱动蛋白,可以衔接纺锤体微管与动点并参与纺锤体检验点调控.为研究CENP-E的作用机理,以其动点结合区域为诱饵蛋白,用酵母双杂交技术从人HeLa细胞cDNA文库中筛选出了Nuf2蛋白.体外的pull-down实验和体内的免疫共沉淀实验表明,Nuf2蛋白通过其卷曲螺旋(coiled-coil)功能域特异结合CENP-E的C末端区域,间接免疫荧光显示Nuf2与CENP-E共定位于细胞有丝分裂期染色体的动点.由此推论,CENP-E通过Nuf2的直接作用参与构筑动点-微管界面,进而参与细胞有丝分裂纺锤体检验点信号转导通路,为染色体正确分离发挥调控作用.
文摘本文以HeLa细胞为材料研究一种着丝粒蛋白CENP-B的基因表达与细胞周期及细胞核骨架的关系。将HeLa细胞同步在不同周期时相,以流式细胞光度术、同位素掺入和ACA着丝粒染色等方法检测细胞同步化效果。我们分别提取了各周期时相细胞的总RNA和Poly(A)^+RNA,用Dot blot和Northern blot杂交方法研究CENP-B在细胞周期中的表达。结果表明,CENP-B基因在细胞周期中的各个时相均有表达,但表达的强度差别很大:G2期表达最强,S期最弱,G1期中的表达介于二者之间;有意义的是CENP-B基因在M期仍然有较强的表达,表现出其在细胞周期中表达的持续性;这种表达的持续性反映了一种可能性:着丝粒、动粒蛋白不断合成,但直到S期后进入G2期时着丝粒、动粒蛋白到一定临界浓度时才开始组装新的动粒。另外,着丝粒、动粒蛋白的持续合成对着丝粒、动粒功能的发挥可能是必需的。用Bam H I限制性内切酶消化处于不同细胞周期时相的HeLa细胞核骨架,提取与核骨架紧密结合的DNA,用^(32)P标记的cDNA为探针研究CENP-B基因与细胞核骨架的结合与其表达的关系。结果证明,在G2期细胞中CENP-B基因表达最强,与细胞核骨架结合最为紧密,G1期细胞中次之,S期中CENP-B基因与核骨架结合最弱,说明CENP-B基因与细胞核骨架结合的紧密度影响其表达强度。
文摘目的探讨CENP-A表达在人类胚胎绒毛染色体分离中的作用。方法应用荧光原位杂交(fluorescence in situ hybridization,FISH)技术检测94例自然流产胚胎绒毛染色体数目,分别用q RT-PCR和Western blotting检测胚胎绒毛组织中CENP-A m RNA和蛋白质相对表达水平。结果 194例自然流产胚胎中检出异常结果病例数共48例,占总病例数的51.06%,其中阳性病例数30例,阳性率为31.91%。比较常见的异常类型有16三体、21三体、22三体、X单体和三倍体。2CENP-A m RNA在实验组和对照组表达水平差异无统计学意义(P>0.05)。3异常组胚胎绒毛组织中CENP-A蛋白相对表达水平明显高于正常组,差异具有统计学意义(P<0.05)。结论着丝粒蛋白CENP-A表达异常与染色体非整倍体引起的自然流产有关。
基金supported by grants 97JC14006 from Shanghai Committee of Science and Technology(No.30025021,39970160,and 39500030)from the Natural Science Foundation of ChinaKSCX2-2-02 from Chinese Academy of Sciences.
文摘Mitosin/CENP-F is a human nuclear protein transiently associated with the outer kinetochore plate in M phase and is involved in M phase progression. LEK1 and CMF1, which are its murine and chicken orthologs, however, are implicated in muscle differentiation and reportedly not distributed at kinetochores.We therefore conducted several assays to clarify this issue. The typical centromere staining patterns were observed in mitotic cells from both human primary culture and murine, canine, and mink cell lines. A C-terminal portion of LEK1 also conferred centromere localization. Our analysis further suggests conserved kinetochore localization of mammalian mitosin orthologs. Moreover, mitosin was associated preferentially with kinetochores of unaligned chromosomes. It was also constantly transported from kinetochores to spindle poles by cytoplasmic dynein. These properties resemble those of other kinetochore proteins important for the spindle checkpoint, thus implying a role of mitosin in this checkpoint. Therefore, mitosin family may serve as multifunctional proteins involved in both mitosis and differentiation.
