Dynamics of hnRNPs and omega speckles in normal and heat shocked live cell nuclei of Drosophila melanogaster
Dynamics of hnRNPs and omega speckles in normal and heat shocked live cell nuclei of Drosophila melanogaster
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黑腹果蝇正常和热休克活细胞核中 hnRNP 和 omega 斑点的动态
DOI：
10.1007/s00412-015-0506-0
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发表时间：
2015
期刊：
影响因子：
1.6
通讯作者：
S. C. Lakhotia
中科院分区：
文献类型：
--
作者：
A. K. Singh;S. C. Lakhotia
在果蝇中，核限长的非编码hsrRNA-n转录本、hnRNPs和一些其他ω加工蛋白组织核质omega斑点。与其他核斑点不同，omega斑点在细胞应激后迅速消失，而hnRNPs和其他相关蛋白质离开染色体位置、核质和消失的斑点，唯一地隔离在HSRω基因座上。在从压力中恢复的过程中，omega斑点再次出现，hnRNP重新分布到正常位置。为了了解omega斑点及其相关蛋白的动态，我们在非应激和应激的果蝇细胞中使用了GFP标记的hnRNPs(Hrb87F、Hrb98DE或Squid)的实时成像。Omega斑点在核质区表现出大小依赖的迁移率，并与核基质Tpr/meGator和SAFB蛋白显著共定位，它们也在胁迫后聚集在HSRω基因位点。热休克或秋水仙素处理后，位于高铁ω基因座的omega斑点不再向核外移动，而是在核质内迅速消失，而染色体和核质的hnRNP随机移动，或者更有可能的是，通过核基质以非颗粒形式向高铁ω基因座转移。在细胞应激过程中，hsrω的持续转录对于隔离传入的hnRNP在该部位是必不可少的。当从压力中恢复时，被隔离的hnRNPs以依赖于ISWI的方式被释放为omega斑点。光漂白研究表明，hnRNP可以在核质、omega斑点、染色体区域和hsrω基因位点之间自由移动，尽管它们在染色体和hsrω基因座的停留时间较长。提出了一个通过高铁ω-n转录本调节核室之间hnRNPs交换的模型。
The nucleus limited long-noncoding hsrω-n transcripts, hnRNPs, and some other RNA processing proteins organize nucleoplasmic omega speckles in Drosophila. Unlike other nuclear speckles, omega speckles rapidly disappear following cell stress, while hnRNPs and other associated proteins move away from chromosome sites, nucleoplasm, and the disappearing speckles to get uniquely sequestered at hsrω locus. Omega speckles reappear and hnRNPs get redistributed to normal locations during recovery from stress. With a view to understand the dynamics of omega speckles and their associated proteins, we used live imaging of GFP tagged hnRNPs (Hrb87F, Hrb98DE, or Squid) in unstressed and stressed Drosophila cells. Omega speckles display size-dependent mobility in nucleoplasmic domains with significant colocalization with nuclear matrix Tpr/Megator and SAFB proteins, which also accumulate at hsrω gene site after stress. Instead of moving towards the nuclear periphery located hsrω locus following heat shock or colchicine treatment, omega speckles rapidly disappear within nucleoplasm while chromosomal and nucleoplasmic hnRNPs move, stochastically or, more likely, by nuclear matrix-mediated transport to hsrω locus in non-particulate form. Continuing transcription of hsrω during cell stress is essential for sequestering incoming hnRNPs at the site. While recovering from stress, the sequestered hnRNPs are released as omega speckles in ISWI-dependent manner. Photobleaching studies reveal hnRNPs to freely move between nucleoplasm, omega speckles, chromosome regions, and hsrω gene site although their residence periods at chromosomes and hsrω locus are longer. A model for regulation of exchange of hnRNPs between nuclear compartments by hsrω-n transcripts is presented.
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影响因子：
3.3
作者：
Pederson, T
通讯作者：
Pederson, T
影响因子：
16
作者：
Deuring, R;Fanti, L;Tamkun, JW
通讯作者：
Tamkun, JW
核体：粘性蛋白质的随机聚集体或大分子组件的坩埚？
影响因子：
11.8
作者：
Matera AG;Izaguire-Sierra M;Praveen K;Rajendra TK
通讯作者：
Rajendra TK
影响因子：
16
作者：
Zobeck KL;Buckley MS;Zipfel WR;Lis JT
通讯作者：
Lis JT
果蝇 Tpr 蛋白同源物定位于染色体外通道网络和核孔复合物中。
影响因子：
4
作者：
Zimowska,G;Aris,JP;Paddy,MR
通讯作者：
Paddy,MR