Fibrillarin-associated Box C/D Small Nucleolar RNAs inTrypanosoma brucei
Fibrillarin-associated Box C/D Small Nucleolar RNAs inTrypanosoma brucei
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布氏锥虫中纤维蛋白相关的 Box C/D 小核仁 RNA
DOI：
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发表时间：
2000
影响因子：
4.8
通讯作者：
S. Baserga
中科院分区：
文献类型：
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作者：
D. A. Dunbar;S. Wormsley;T. Lowe;S. Baserga
我们报告的鉴定17盒C/D原纤蛋白相关的小核仁RNA（snoRNA）从古老的真核生物，布氏锥虫。为了系统地分离和鉴定这些snoRNA，T.克隆了盒C/D snoRNA共同蛋白原纤蛋白的布氏杆菌cDNA，并在兔中产生了重组原纤蛋白的多克隆抗体。T.用抗原纤维蛋白抗体检测布鲁氏菌提取物表明，该锥虫至少有30个与原纤维蛋白相关的snoRNA。我们已经对其中的17个进行了测序，并将它们命名为TBR。B. rucei RNA 1-17。它们都具有保守的盒C、D、C′和D′元件，这是真核生物中与原纤维蛋白相关的snoRNA的标志。其中14个是新的T.布鲁氏菌snoRNAs。15个具有成熟rRNA的潜在指导区域，表明它们参与2′-O-核糖甲基化。事实上，八个核糖甲基化已被映射在rRNA的snoRNA序列预测的网站。比较基因组学表明，17个中的6个是已知酵母和脊椎动物甲基化指导snoRNA的第一个锥虫同源物。结果表明，T.布氏杆菌中存在许多与原纤维蛋白相关的box C/D snoRNA，它们在rRNA的2′-O-核糖甲基化中发挥作用，而将box D或D′上游第5个核苷酸甲基化的机制起源于早期真核生物。
We report the identification of 17 box C/D fibrillarin-associated small nucleolar RNAs (snoRNAs) from the ancient eukaryote, Trypanosoma brucei. To systematically isolate and characterize these snoRNAs, the T. brucei cDNA for the box C/D snoRNA common protein, fibrillarin, was cloned and polyclonal antibodies to the recombinant fibrillarin protein were generated in rabbits. Immunoprecipitations from T. bruceiextracts with the anti-fibrillarin antibodies indicated that this trypanosomatid has at least 30 fibrillarin-associated snoRNAs. We have sequenced seventeen of them and designated them TBR for T . b rucei RNA 1–17. All of them bear conserved box C, D, C′, and D′ elements, a hallmark of fibrillarin-associated snoRNAs in eukaryotes. Fourteen of them are novel T. brucei snoRNAs. Fifteen bear potential guide regions to mature rRNAs suggesting that they are involved in 2′-O-ribose methylation. Indeed, eight ribose methylations have been mapped in the rRNA at sites predicted by the snoRNA sequences. Comparative genomics indicates that six of the seventeen are the first trypanosome homologs of known yeast and vertebrate methylation guide snoRNAs. Our results indicate that T. brucei has many fibrillarin-associated box C/D snoRNAs with roles in 2′-O-ribose methylation of rRNA and that the mechanism for targeting the nucleotide to be methylated at the fifth nucleotide upstream of box D or D′ originated in early eukaryotes.