Tissue-specific expression and dynamic organization of SR splicing factors in Arabidopsis
Tissue-specific expression and dynamic organization of SR splicing factors in Arabidopsis
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DOI：
10.1091/mbc.e04-02-0100
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发表时间：
2004-06-01
影响因子：
3.3
通讯作者：
Spector, DL
中科院分区：
文献类型：
--
作者：
Fang, YD;Hearn, S;Spector, DL
前体mRNA剪接机制的组织已经在哺乳动物和酵母细胞中被广泛研究，而在活的植物细胞和完整生物体的不同细胞类型中知之甚少。在这里，我们报告的表达，组织和动态的前mRNA剪接因子（SR 33，SR 1/atSRp 34，atSRp 30）的控制下，其内源性启动子在拟南芥。观察到不同的组织特异性表达模式，并确定了这些蛋白质在不同细胞类型的细胞核内的分布差异。这些因子定位在一个细胞类型依赖的斑点图案，以及被弥漫分布在整个核质。电子显微镜分析表明，这些斑点对应于染色质间颗粒簇。延时显微镜显示斑点在受限的核空间内移动，并且它们的组织在细胞周期中改变。光漂白分析后的荧光恢复显示，在核斑点的剪接因子的快速交换率。植物斑点的动态组织与细胞的转录活性密切相关。拟南芥细胞核中斑点的组织和动态行为为理解细胞核的功能区室化及其与单个生物体的各种细胞类型内染色质组织的关系提供了重要的见解。
The organization of the pre-mRNA splicing machinery has been extensively studied in mammalian and yeast cells and far less is known in living plant cells and different cell types of an intact organism. Here, we report on the expression, organization, and dynamics of pre-mRNA splicing factors (SR33, SR1/atSRp34, and atSRp30) under control of their endogenous promoters in Arabidopsis. Distinct tissue-specific expression patterns were observed, and differences in the distribution of these proteins within nuclei of different cell types were identified. These factors localized in a cell type-dependent speckled pattern as well as being diffusely distributed throughout the nucleoplasm. Electron microscopic analysis has revealed that these speckles correspond to interchromatin granule clusters. Time-lapse microscopy revealed that speckles move within a constrained nuclear space, and their organization is altered during the cell cycle. Fluorescence recovery after photobleaching analysis revealed a rapid exchange rate of splicing factors in nuclear speckles. The dynamic organization of plant speckles is closely related to the transcriptional activity of the cells. The organization and dynamic behavior of speckles in Arabidopsis cell nuclei provides significant insight into understanding the functional compartmentalization of the nucleus and its relationship to chromatin organization within various cell types of a single organism.