Novel intron-encoded small nucleolar RNAs with long sequence complementarities to mature rRNAs involved in ribosome biogenesis
Novel intron-encoded small nucleolar RNAs with long sequence complementarities to mature rRNAs involved in ribosome biogenesis
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DOI：
10.1139/o95-091
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发表时间：
1995-11-01
期刊：
影响因子：
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通讯作者：
Renalier, MH
中科院分区：
文献类型：
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作者：
Bachellerie, JP;Nicoloso, M;Renalier, MH
最近，在编码核糖体、核糖体相关蛋白或核仁蛋白的基因内含子中发现了几种新的snorna。我们目前正在研究其中的四种内含子snorna。其中U20、U21和U24在结构上是密切相关的。它们分别包含在温血脊椎动物核蛋白L5和核糖体蛋白L7a的编码基因中。这三种代谢稳定的snorna与核仁蛋白纤维蛋白相互作用。此外，它们还显示出与snoRNA U14密切相关的共同特征。U14含有两个与18S rRNA互补的小链，这两个小链是产生18S rRNA所必需的。U20与18S rRNA具有21个核苷酸（nt）长的互补关系。U21与真核生物28S rRNA中的一个不变序列具有13个互补序列。U24与高度保守的28S rRNA具有两个独立的12 nt长的互补链。系统发育证据支持这三种snorna与pre-rRNA配对的根本重要性，这可能涉及在pre-rRNA组装过程中控制pre-rRNA折叠。通过转染小鼠细胞，我们也分析了U20的加工过程，发现用于U20加工的内含子RNA的-cis作用信号仅限于成熟的snoRNA序列。最后，我们记录了这三种内含子snoRNAs在真核生物进化过程中宿主基因的变化。
Recently, several new snoRNAs encoded in introns of genes coding for ribosomal, ribosome-associated, or nucleolar proteins have been discovered. We are presently studying four of these intronic snoRNAs. Three of them, U20, U21, and U24, are closely related to each other on a structural basis. They are included in genes encoding nucleolin and ribosomal proteins L5 and L7a, respectively, in warm-blooded vertebrates. These three metabolically stable snoRNAs interact with nucleolar protein fibrillarin. In addition, they display common features that make them strikingly related to snoRNA U14. U14 contains two tracts of complementarity to 18S rRNA, which are required for the production of 18S rRNA. U20 displays a 21 nucleotide (nt) long complementarity to 18S rRNA. U21 contains a 13 nt complementarity to an invariant sequence in eukaryotic 28S rRNA. U24 has two separate 12 nt long complementarities to a highly conserved tract of 28S rRNA. Phylogenetic evidences support the fundamental importance of the pairings of these three snoRNAs to pre-rRNA, which could be involved in a control of pre-rRNA folding during preribosome assembly. By transfection of mouse cells, we have also analyzed the processing of U20 and found that the -cis acting signals for its processing from intronic RNA are restricted to the mature snoRNA sequence. Finally, we have documented changes of host genes for these three intronic snoRNAs during the evolution of eukaryotes.