Role of the box C D motif in localization of small nucleolar RNAs to coiled bodies and nucleoli
Role of the box C D motif in localization of small nucleolar RNAs to coiled bodies and nucleoli
复制标题
DOI：
10.1091/mbc.10.7.2131
复制
发表时间：
1999-07-01
影响因子：
3.3
通讯作者：
Terns, MP
中科院分区：
文献类型：
--
作者：
Narayanan, A;Speckmann, W;Terns, MP
小核仁RNA(SnoRNAs)是一个真核RNA大家族，在核糖体的生物发生中发挥核仁内的作用。一类主要的snoRNAs是box C/D snoRNAs，因其保守的box C和box D序列元件而得名。我们通过分析注射到非洲爪哇卵母细胞核中的荧光标记的U3、U8和U14 snoRNAs的核内分布，研究了顺式作用序列和核内结构在box C/D snoRNAs核仁定位中的作用。对U3 RNA变体的分析表明，由box C‘、box D和U3的3’末端茎组成的box C/D基序是U3 snoRNA核仁定位的必要条件和充分条件。U8和U14的box C/D基序的元件的破坏也阻止了核仁的定位，表明所有的box C/D snoRNA都使用共同的核仁靶向机制。最后，我们发现野生型Box C/D snoRNAs在定位到核仁之前会短暂地与盘绕体结合，而缺乏完整box C/D基序的变体RNA会滞留在盘绕体中。这些结果表明，盘状小体在box C/D snoRNAs的生物发生和/或核内转运中发挥了作用。
Small nucleolar RNAs (snoRNAs) are a large family of eukaryotic RNAs that function within the nucleolus in the biogenesis of ribosomes. One major class of snoRNAs is the box C/D snoRNAs named for their conserved box C and box D sequence elements. We have investigated the involvement of cis-acting sequences and intranuclear structures in the localization of box C/D snoRNAs to the nucleolus by assaying the intranuclear distribution of fluorescently labeled U3, U8, and U14 snoRNAs injected into Xenopus oocyte nuclei. Analysis of an extensive panel of U3 RNA variants showed that the box C/D motif, comprised of box C', box D, and the 3' terminal stem of U3, is necessary and sufficient for the nucleolar localization of U3 snoRNA. Disruption of the elements of the box C/D motif of U8 and U14 snoRNAs also prevented nucleolar localization, indicating that all box C/D snoRNAs use a common nucleolar-targeting mechanism. Finally, we found that wild-type box C/D snoRNAs transiently associate with coiled bodies before they localize to nucleoli and that variant RNAs that lack an intact box C/D motif are detained within coiled bodies. These results suggest that coiled bodies play a role in the biogenesis and/or intranuclear transport of box C/D snoRNAs.