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1.
    
Spindle checkpoint is an important biochemical signaling cascade during mitosis which monitors the fidelity of chromosome segregation, and is mediated by protein kinases Mps1 and Bub1/BubR1. Our recent studies show that kinesin-related motor protein CENP-E interacts with BubR1 and participates in spindle checkpoint signaling. To elucidate the molecular mechanisms underlying spindle checkpoint signaling, we carried out proteomic dissection of human cell kinetochore and revealed protein kinase TTK, human homologue of yeast Mps1. Our studies show that TTK is localized to the kinetochore of human cells, and interacts with CENP-E, suggesting that TTK may play an important role in chromosome segregation during mitosis.  相似文献   

2.
Kinesins are microtubule-based motor proteins that perform diverse functions[1―6], including the transloca- tion of vesicles, organelles, chromosomes, proteincomplexes, RNA-binding proteins (RNPs), etc. They also help to orchestrate microtubule dynamics …  相似文献   

3.
首次在硬化性肌膜炎患者血清中发现有抗着丝点抗体(ACA),可使 Hep-2间期细胞核及 M 期细胞染色体着丝点显示分散的荧光斑点.用 ACA 血清对小鼠几种器官的冰冻切片或涂片进行免疫荧光研究,可见无论幼龄或老龄小鼠的肝、十二指肠、脑皮层细胞及老龄小鼠睾丸生精细胞均有明亮的荧光斑点.绒毛顶端细胞呈均匀性荧光.  相似文献   

4.
    
《科学通报(英文版)》1995,40(20):1734-1734
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5.
This paper investigates the effects of sense and antisense centromere/kinetochore complex protein-B (CENP-B) in cell cycle regulation. Full-length cenpb cDNA was subcloned into pBI-EGFP eukaryotic expression vector in both sense and antisense orientation. HeLa-Tet-Off cells were transfected with sense or antisense cenpb vectors. Sense transfection of HeLa-Tet-Off cells resulted in the formation of a large centromere/kinetochore complex, and apoptosis of cells following several times of cell division. A stable antisense cenpb transfected cell line, named HACPB, was ob- tained. The centromere/kinetochore complex of HACPB cells became smaller than control HeLa-Tet-Off cells and scattered, and the expression of CENP-B was down-regulated. In addition, delayed cell cycle progression, inhibited malignant phenotype, restrained ability of tumor formation in nude mice, and delayed entry from G2fM phase into next G1 phase were observed in HACPB cells. Furthermore, the expression of cyclin-dependent kinases (CDKs), cyclins, and CDK inhibitors (CKIs) were modulated during different phases of the cell cycle. CENP-B is an essential protein for the maintenance of the structure and function of centromere/kinetochore complex, and plays important roles in cell cycle regulation.  相似文献   

6.
食用菜籽蛋白的提取及其功能特性的研究   总被引:3,自引:0,他引:3  
研究了食用菜籽蛋白的提取方法及其功能特性,并对其应用前景进行了讨论。  相似文献   

7.
    
It is generally believed that the equal distribution of genetic materials to two daughter cells during mitosis is the key to cell health and development. During the dynamic process, spindle checkpoint plays a very important role in chromosome movements and final sister chromatid separation. The equal and precise segregation of chromosomes contributes to the genomic stability while aberrant separations result in chromosome instability that causes pathogenesis of certain diseases such as Down’s syndrome and cancers. Kinetochore and its regulatory proteins consist of the spindle checkpoint and determine the spatial and temporal orders of chromosome segregation.  相似文献   

8.
本文介绍了近二十年来分离蛋白质的新方法及制备型设备的进展.共分三大类:即电泳、场流分级和等电聚焦。介绍了其中的技术关键,如建立pH梯度的方法、流动方向与电场垂直的新概念以及近10年来发展的多种类型的制备装置。其中一些较好的装置的处理能力已超过制备型的凝胶色谱和亲和色谱装置,达到了每天分离几克到几百克蛋白质的水平。  相似文献   

9.
目的: 为了解析芽殖酵母 Num1 蛋白在纺锤体定位和线粒体中的调节机制.方法: 利用大肠杆菌原核表达并纯化了在 Num1 功能中起核心作用的补丁组装(PA) 结构域的重组蛋白, 通过蛋白体外结合实验(Pull-down) 分离了酵母细胞中与 PA 结构域相结合的蛋白复合物,并对其进行了质谱分析.结果: 鉴定了一系列新的 Num1 互作蛋白,包括核糖体蛋白,参与蛋白折叠、分配及转运的内质网和高尔基复合体蛋白, 参与基因转录和翻译的核酸酶和蛋白酶,及其他功能的蛋白.结论: Num1 的互作蛋白的鉴定为进一步研究 Num1 的作用机制奠定了基础.  相似文献   

10.
Actin is a protein abundant in cells. Recently, it has been proved to be universally existent in the nuclei of many cell types. Actin and actin-binding proteins, as well as aetin-related proteins, are necessary for the mediation of the conformation and function of nuclear actin, including the transformation of actin between unpolymerized and polymerized, chromatin remodeling, regulation of gene expression and RNA processing as well as RNA transportation. In this paper, we summarized the progresses in the research of nuclear actin.  相似文献   

11.
双向电泳检测技术综述   总被引:1,自引:0,他引:1  
目前蛋白质组学(proteome)正在成为分析化学的研究热点,双向聚丙烯酰胺凝胶电泳(2-DE)以其高通量和极高的分辨率成为蛋白质组学的核心技术,本文综述了不同类型的双向电泳检测技术的原理,比较分析了各种技术的优势和不足,并对双向电泳技术在蛋白质组学中今后的发展作了展望.  相似文献   

12.
The actin cytoskeleton is an important component of eukaryotic cell cytoskeleton and is temporally and spatially controlled by a series of actin binding proteins (ABPs). Among ABPs, formin family proteins have attracted much attention as they can nucleate unbranched actin filament from the profilin bound actin pool in vivo. In recent years, a number of formin family members from different organisms have been reported, and their characteristics are known more clearly, although some questions are still to be clarified. Here, we summarize the structures, func-tions and nucleation mechanisms of different formin family proteins, intending to compare them and give some new clues to the study of formins.  相似文献   

13.
HL-60细胞分化对动粒蛋白及其基因表达的影响   总被引:2,自引:0,他引:2  
以人早幼粒白血病细胞HL-60为实验材料,用终浓度1μmol·L-1甲酸(RA)和二甲亚砜(DMSO)分别连续处理细胞6d后,可使HL-60细胞按粒系途径定向成熟分化,即表现出核分叶,具有NBT还原能力的正常粒细胞的形态和功能特征。利用ACA间接免疫荧光方法,观察到在终未分化的细胞核中荧光斑点强度要明显弱于对照细胞。用RNANorthern和斑点杂交方法研究发现,在HL-60细胞诱导分化过程中,Id,CyclinB1基因表达很快受到明显抑制,在终末分化的细胞中已基本被关闭;CENP-B基因表达水平也明显降低,但表达变化过程与Id和CyclinB1基因有所差异。  相似文献   

14.
Acidithiobacillus caldus plays an important role in commercial bioleaching.To understand how NaCl stress adaptation occurs in A.caldus,we grew A.caldus strain SM-1 in media containing high NaCl concentrations.SM-1 grew at concentrations of up to 1.0-mol L~(-1)NaCl,but growth was severely inhibited at higher concentrations.Proteomic analysis showed that SM-1 used multiple strategies to respond to NaCl stress.In addition to several heatshock proteins,enzymes involved in proline biosynthesis increased under NaCl stress.In addition,two DNA-binding proteins and a third protein of unknown function(Atc_(1291)),which was subsequently identified as a putative single-stranded DNA-binding protein,were up-regulated in the presence of NaCl stress.These DNA-binding proteins might play a role in response to osmotic stress.Atc_(1291)was cloned and expressed in Escherichia coli.Surprisingly,we found that E.coli BL21/pET28a-atc_(1291)grew to higher cell densities than E.coli BL21/pET28a,regardless of NaCI stress.Homologs to Atc_(1291)were identified in several groups of Proleohacleria.The role of Atc_(1291)in enhancing cell growth needs further investigation.  相似文献   

15.
    
It is a fundamental task to ensure the faithful transmission of genetic information across generations for eukaryote species. The centromere is a specialized chromosomal region that is essential for mediating sister chromatid alignment and separation during mitosis. Centromere identity is epigenetically determined by nucleosome-containing centromere protein A (CENP-A). The CENP-A nucleosome provides the foundation for the association of the inner kinetochore and the assembly of the outer kinetochore in mitosis. Here we review centromere identity determination, inner kinetochore function and assembly, and outer kinetochore function and assembly. In particular, we focus on the recent advances in the structure-activity relationship of the constitutive centromere-associated network (CCAN). CCAN structure information sheds new light on our understanding of centromere and kinetochore functions and dynamic organization.  相似文献   

16.
用含有酵母tRNA和小白鼠氨酰tRNA合成酶的异源检测体系,测定到小白鼠脑组织的氨酰tRNA合成酶,运载氨基酸tRNA的活力,随小白鼠年龄和不同氨基酸而异,是否小白鼠全脑的不溶蛋白,也随年龄而有变化。作者用聚丙烯酰胺凝胶等电聚焦技术,对小白鼠全脑的不溶蛋白进行了测定。根据凝胶等电聚焦图谱证实,不同年龄小白鼠全脑不溶蛋白的主要组分是相似的,但在530毫微米波长处的吸光值有明显的差异。这种变化结果是否与该组分的氨基酸组成及其含量有关,有待进一步探究。  相似文献   

17.
    
《科学通报(英文版)》1993,38(24):2083-2083
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18.
    
《科学通报(英文版)》1990,35(2):134-134
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19.
    
The role of heterotrimeric G protein in signal transduction pathway of extracellular calmodulin in regulating rbcS expression was examined in suspension-cultured cells of transgenic tobacco. Pharmalogical experiments indicated that G protein agonist cholera toxin enhanced rbcS expression and heterotrimeric G protein antagonist pertussis toxin inhibited rbcS expression in transgenic tobacco cells. Pertussis toxin also inhibited the enhancement effect caused by exogenous purified calmodulin on rbcS expression, whereas cholera toxin completely reversed the inhibitory effects caused by anti-calmodulin serum on rbcS expression. The right side-out vesicles from tobacco cell membrane were purified, which contained all of substrates for fluometric assay of GTPase activity. Exogenous purified calmodulin, when adding directly to the medium of plasma membrane vesicles, significantly activated GTPase activity in the right side-out plasma membrane vesicles, and this increase in GTPase activity was completely inhibited both by heterotrimeric G proteins antagonist pertussis toxin and nonhy-drolyzable GTP analogs GMP-PCP. These results provided the evidence that heterotrimeric G proteins may be involved in signal transduction pathways of extracellular calmodulin to regulate rbcS gene expression.  相似文献   

20.
松树萎蔫病是由松材线虫(Bursaphelenchusxylophilus)引起的松属树种上的一种毁灭性的病害,因此,对松材线虫致病机理的研究具有重要的理论和实践意义.根据松材线虫和拟松材线虫致病性的差异,通过活体染色对松材线虫和拟松材线虫分泌-排泄物进行了比较研究,发现松材线虫和拟松材线虫线虫分泌-排泄物存在明显的差别,这种差别可能与松材线虫的致病性有关.  相似文献   

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