MUTATIONS IN CONSERVED DOMAINS OF U14 RNA IMPAIR 18S RIBOSOMAL-RNA PRODUCTION IN SACCHAROMYCES-CEREVISIAE
MUTATIONS IN CONSERVED DOMAINS OF U14 RNA IMPAIR 18S RIBOSOMAL-RNA PRODUCTION IN SACCHAROMYCES-CEREVISIAE
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DOI：
10.1007/bf00360440
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发表时间：
1990-01-01
影响因子：
2.8
通讯作者：
FOURNIER, MJ
中科院分区：
文献类型：
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作者：
LEMPICKI, RA;JARMOLOWSKI, A;FOURNIER, MJ
小核仁 RNA (snoRNA) 与核糖体生物发生有关，基于：i) rDNA 转录装置的细胞下定位，ii) 与各种前体和成熟 rRNA 物种的关联，iii) 与 rRNA 的互补性，以及 iv) 前体 rRNA 加工的破坏，伴随着两个特定 snoRNA 物种的丢失。与核质剪接体snRNA一样，snoRNA以RNP颗粒存在，即snoRNP。其中一些含有丰富的 34 kDa 核仁蛋白，纤维蛋白。来自硬皮病患者的纤维蛋白特异性抗血清可沉淀来自各种来源的 U3 snoRNP 以及来自哺乳动物细胞的 U8 和 U13。这一发现强烈表明原纤维蛋白是几种 snoRNP 的共同成分，并且这种关联在进化上是保守的。两个保守的 snoRNA 序列元件（指定为框 C 和框 D）与抗原纤维蛋白沉淀相关，并已被指定为可能的原纤维蛋白结合位点 (1)。迄今为止，已在酿酒酵母中鉴定出 9 种 snoRNA。这些 RNA 已被证明在去蛋白但非变性条件下与 20S、27S 和 35S prerRNA 不同地相关 (2, 3)。有趣的是，九个物种中只有两个对生长至关重要，即 U3 和 U14。通过 snRNA 耗尽分析，U14 RNA（本研究的主题）和第二种非必需 snoRNA snR10 已与核糖体 RNA 的加工联系起来。破坏可有可无的 snR 10 基因会产生冷敏感表型，并导致 35S rRNA 转录本的加工受损 (4)。由于 U14 基因表达的抑制，35S RNA 的加工在 U14 耗尽的细胞中也存在缺陷。在这种情况下，细胞积累中间体的能力严重受损 (5)。
The small nucleolar RNAs (snoRNA) have been implicated in ribosome biogenesis, based on: i) subeellular localization with the rDNA transcriptional apparatus, ii) demonstrated associations with various pre-and mature rRNA species, iii) complementarity with rRNA and iv) disruption of precursor rRNA processing which accompanies loss of two specific snoRNA species. Like the nucleoplasmic splicesomal snRNAs, the snoRNAs exist as RNP particles, ie, snoRNPs. Some of these contain the abundant 34 kDa nucleolar protein, fibrillarin. Fibrillarin-specific antisera from scleroderma patients precipitate U3 snoRNPs from a variety of sources and U8 and U13 from mammalian cells. This f'mding strongly suggests that fibrillarin is a component common to several snoRNPs and that this association has been evolutionarily conserved. Two conserved snoRNA sequence elements, designated box C and box D, correlate with anti-fibrillarin precipitation and have been nominated as possible fibrillarin binding sites (1).To date, nine snoRNA species have been identified in Saccharomyces cerevisiae. These RNAs have been shown to be associated with, variously, 20S, 27S, and 35S prerRNAs, under deproteinized, but non-denaturing conditions (2, 3). Interestingly, only two of the nine species are essential for growth, U3 and U14. U14 RNA-the subject of the present study, and a second, non-essential snoRNA, snRl0, have been linked with processing of ribosomal RNA, through snRNA-depletion analysis. Disruption of the dispensable snR 10 gene yielded a cold-sensitive phenotype with impaired processing of the 35S rRNA transcript (4). Processing of 35S RNA is also defective in cells depleted of U14, by repression of U14 gene expression. Cells in this condition are sererely impaired in the ability to accumulate intermediates (5).