RNA-mediated interaction of Cajal bodies and U2 snRNA genes.
RNA-mediated interaction of Cajal bodies and U2 snRNA genes.
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DOI：
10.1083/jcb.200105084
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发表时间：
2001-08-06
影响因子：
7.8
通讯作者：
Matera, A G
中科院分区：
文献类型：
--
作者：
Frey, M R;Matera, A G
卡哈尔体 (CB) 是参与 RNA 代谢的核结构，可积累高浓度的小核核糖核蛋白 (snRNP)。值得注意的是，CB 优先与间期人类细胞中的特定基因组位点相关，包括几个 snRNA 和组蛋白基因簇。为了揭示参与基因和 CB 相互作用的功能元件，我们分析了稳定转染的 U2 snRNA 基因人工阵列的表达和亚细胞定位。尽管启动子取代阵列与 CB 共定位，但含有基因内缺失的构建体却不然。其他实验确定了 CB 内对与天然 U2 基因相关的重要因素。抑制核输出或 U2 snRNP 的定向降解导致 CB 中 U2 snRNA 水平显着下降，并强烈破坏与 U2 基因的相互作用。总之，这些结果说明了对 snRNA 转录本以及 CB 中 snRNP（或 snRNP 蛋白）的存在的特定要求。因此，我们的数据为 CB 与 snRNA 位点相互作用的机制提供了重要的见解，加强了这种核亚细胞器在 snRNP 生物发生中的假定作用。
Cajal bodies (CBs) are nuclear structures involved in RNA metabolism that accumulate high concentrations of small nuclear ribonucleoproteins (snRNPs). Notably, CBs preferentially associate with specific genomic loci in interphase human cells, including several snRNA and histone gene clusters. To uncover functional elements involved in the interaction of genes and CBs, we analyzed the expression and subcellular localization of stably transfected artificial arrays of U2 snRNA genes. Although promoter substitution arrays colocalized with CBs, constructs containing intragenic deletions did not. Additional experiments identified factors within CBs that are important for association with the native U2 genes. Inhibition of nuclear export or targeted degradation of U2 snRNPs caused a marked decrease in the levels of U2 snRNA in CBs and strongly disrupted the interaction with U2 genes. Together, the results illustrate a specific requirement for both the snRNA transcripts as well as the presence of snRNPs (or snRNP proteins) within CBs. Our data thus provide significant insight into the mechanism of CB interaction with snRNA loci, strengthening the putative role for this nuclear suborganelle in snRNP biogenesis.