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1.
Nucleolar proteome dynamics   总被引:2,自引:0,他引:2  
Andersen JS  Lam YW  Leung AK  Ong SE  Lyon CE  Lamond AI  Mann M 《Nature》2005,433(7021):77-83
The nucleolus is a key organelle that coordinates the synthesis and assembly of ribosomal subunits and forms in the nucleus around the repeated ribosomal gene clusters. Because the production of ribosomes is a major metabolic activity, the function of the nucleolus is tightly linked to cell growth and proliferation, and recent data suggest that the nucleolus also plays an important role in cell-cycle regulation, senescence and stress responses. Here, using mass-spectrometry-based organellar proteomics and stable isotope labelling, we perform a quantitative analysis of the proteome of human nucleoli. In vivo fluorescent imaging techniques are directly compared to endogenous protein changes measured by proteomics. We characterize the flux of 489 endogenous nucleolar proteins in response to three different metabolic inhibitors that each affect nucleolar morphology. Proteins that are stably associated, such as RNA polymerase I subunits and small nuclear ribonucleoprotein particle complexes, exit from or accumulate in the nucleolus with similar kinetics, whereas protein components of the large and small ribosomal subunits leave the nucleolus with markedly different kinetics. The data establish a quantitative proteomic approach for the temporal characterization of protein flux through cellular organelles and demonstrate that the nucleolar proteome changes significantly over time in response to changes in cellular growth conditions.  相似文献   

2.
在只经戊醛未经锇酸固定的洋忽和百合小孢子母细胞核的超薄切片中,看到一种由颗粒和纤维组成的网络结构。减数第一次发裂前期的早期,这种结构分布于整个细胞核内的非染色质区和核仁腔隙,并与染色质和核仁相连,随着细胞的发育,分布在非染色质区的颗粒和纤维的密度逐渐变小。当细胞进入中期以后,这些颗粒和纤维结构消失而染色体之间的网络结构却依然清晰可见。该结构经胃蛋白酶的消化处理后消失。经ETDA倒退染色后不能被漂白  相似文献   

3.
用银染法观察了蓖麻蚕生殖细胞的染色体。结果表明:有丝分裂中期染色体上无特异的NORs;精母细胞减数分裂偶线期和粗线期核仁逐步弥散,粗线期之后有一个染色体分散为染色质,核仁弥散于其中形成嗜银的二价体的第二收缩期和混乱期;卵母细胞的相应时期,有一个核仁扩增的过程。依据染色体嗜银性的强弱,探讨了前期Ⅰ,中期Ⅰ以及有丝分裂中期染色体的rDNA转录活性。  相似文献   

4.
本文用不同进化类型的植物为材料,采用BernhardRNP优先染色技术,对染色体中的RNP物质进行了系统的观察,结果发现,在植物染色体中普遍存在有RNP,且分布特点基本相同,除在染色体周边由较多RNP构成“鞘状”结构外,在染色体的内部也随机分布有少量的RNP,此结果经NaOH处理得到了进一步的证实。  相似文献   

5.
用抗核仁抗原NAg-1的抗血清对各种白血病人骨髓组织进行免疫荧光染色.结果表明,急性白血病患者的NAg-1阳性细胞率显著高于正常人及各种非白血病贫血患者.在处于完全缓解的白血病患者中,具有较高的NAg-1阳性率者(>10%)比较低者(<10%)更易复发.  相似文献   

6.
Y Hiraoka  J S Minden  J R Swedlow  J W Sedat  D A Agard 《Nature》1989,342(6247):293-296
Although the dynamic behaviour of chromosomes has been extensively studied in their condensed state during mitosis, chromosome behaviour during the transition to and from interphase has not been well documented. Previous electron microscopic studies suggest that chromosomes condense in a non-uniform fashion at the nuclear periphery. But chromosome condensation is a complicated and dynamic process and requires continuous observation in living tissues to be fully understood. Using a recently developed three-dimensional time-lapse fluorescence microscopy technique, we have observed chromosomes as they relax from telophase, through interphase, until their condensation at the next prophase. This technique has been improved to produce higher-resolution images by implementing new stereographic projection and computational processing protocols. These studies have revealed that chromosomal regions on the nuclear envelope, distinct from the centromeres and telomeres, serve as foci for the decondensation and condensation of diploid chromosomes. The relative positions of the late decondensation sites at the beginning of interphase appear to correspond to the early condensation sites at the subsequent prophase.  相似文献   

7.
1.材料和方法参照Goodpasture的Ag-As法和Bloom,Lau等的Ag法,我们稍加改良应用于研究鱼类的NORs,可获得较好的银染效果.具体方法如下: ①Ag-As法:将干燥后15天左右的片子加4滴AgNO_3溶液(20-30%),盖上长方形的玻片,放在底部铺有润湿滤纸的培养皿中,放于60℃恒温箱中15小时后用自来水  相似文献   

8.
利用特异性抗Ser28磷酸化组蛋白H3抗体,应用间接免疫荧光标记技术,标记人乳腺癌细胞 (MCF-7)和小鼠成纤维细胞(NIH 3T3),用激光共聚焦显微术研究这两种哺乳动物细胞中Ser28磷酸化组蛋白 H3在有丝分裂过程中的动态分布,以研究Ser28磷酸化组蛋白在细胞有丝分裂过程中的作用.结果表明,Ser28 的磷酸化作用是这两种细胞有丝分裂期的特有事件.组蛋白H3的Ser28磷酸化信号首先出现在早期的核外周, Ser28磷酸化在中期达到高峰,并扩展到染色体的所有部分,后期和末期逐渐减退,随着胞质分裂的完成而消失. 实验结果表明,组蛋白H3 Ser28的磷酸化与有丝分裂染色体的凝集和解凝集过程有着时间和空间上的相关性. Ser28磷酸化使得组蛋白H3氨基末端的正电荷数降低,这可能是导致染色质变构凝集的原因之一.有丝分裂期 间组蛋白H3在Ser28位置磷酸化过程与Ser10相比有明显的差异,因此在动物细胞中,组蛋白H3氨基末端这 两个不同丝氨酸残基的磷酸化可能有不同的生物学功能.  相似文献   

9.
The role of contractile proteins in the structural organisation of the interphase nucleus and of metaphase chromosomes is largely unknown. Actin has been found in interphase nuclei of different species, especially in association with condensed chromatin. In the germinal vesicle (nucleus) of Xenopus oocytes, actin has been localised in the nuclear gel supporting the chromosomes and the extrachromosomal nucleoli. It has been reported that the premeiotic lampbrush chromosomes in these germinal vesicles are positively stained for actin and tubulin by the immunoperoxidase technique. Moreover, the longitudinal contraction of these chromosomes is ATP dependent. Therefore it has been suggested that actin participates in the structural organisation of the highly specialised lampbrush chromosomes. However, actin is not a major component of the metaphase chromosome scaffold. The results reported here suggest that actin is involved in the condensation of Xenopus chromosomes.  相似文献   

10.
本文应用TEM技术、电镜细胞化学、胶体金标记和银染技术结合研究了大鼠骨髓细胞染色体现有架。超薄切片结合RNP优先染色法在染色体原位显示RNP,同时又结合银染电镜扭亏为盈主RNase-胶体金定位显示RNA,结果显示金颗粒与银颗粒在染色体中分布的位置与RNP所在部位恰好一致。说明RNP中的蛋白质含有角染的酸性蛋白,即所观察到的染色体骨架非组蛋白、RNP中的蛋白部分,银染蛋白三者是一致的。  相似文献   

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