Synthesis, Structure, and Function of Eukaryotic snRNA U14

在原核生物和真核生物中都发现了各种不同的低分子RNA群体，它们在DNA复制、RNA转录和加工以及mRNA翻译等广泛的细胞过程中发挥着重要作用。本实验室的研究重点是一种名为SnRNAU14的小核RNA的结构和功能。这种进化上保守的真核lmwRNA物种具有与18S核糖体RNA进行分子间碱基配对的保守能力。小鼠和非洲爪哇U14的分子和细胞特征以及酵母U14的遗传分析有力地表明了在真核rRNA合成和/或加工中的作用。最近的实验非常令人惊讶地揭示了小鼠和非洲爪哇U14基因在构成表达的同源hsc70热休克基因内含子5中的定位，hsc70是单链RNA的独特基因组组织。本研究中概述的实验将检查真核细胞SnRNAU14的合成、结构和功能。确定了与U14生物发生有关的生物合成途径。U14的合成和细胞分布将在正常和异常生长的细胞中进行研究。U14‘S在rRNA加工中的作用以及可能参与热休克/应激反应将被研究。最后，结构研究将定义一个进化上保守的U14二级结构，确定参与分子间杂交的U14/18S rRNA序列，并表征可能的U14核糖核蛋白复合体的U14相关蛋白质。这些研究的结果将有助于更好地理解这种独特的、在进化上具有重要意义的真核lmwRNA的结构/功能关系。

Diverse populations of low molecular weight RNAs, found in both prokaryotic and eukaryotic organsims, have been shown to play important roles in a wide variety of cellular processes including DNA replication, RNA transcription and processing, and mRNA translation. This laboratory's research efforts are focused on the structure and function of one such small nuclear RNA designated snRNA U14. This evolutionarily conserved eukaryotic lmwRNA species possesses a conserved ability to intermolecularly base-pair with 18s ribosomal RNA. Molecular and cellular characterization of mouse and Xenopus U14 as well as genetic analysis of yeast U14 strongly indicate a role in eukaryotic rRNA synthesis and/or processing. Recent experiments have quite surprisingly revealed the positioning of the mouse and Xenopus U14 genes within intron 5 of the constitutive-expressed cognate hsc70 heat shock gene, a unique genomic organization for an snRNA. The experiments outlined in this investigation will examine the synthesis, structure, and function of eukaryotic snRNA U14. The biosynthetic pathway responsible for U14 biogenesis defined. The synthesis and cellular distribution of U14 will be studied in both normally and abnormally growing cells. U14's role in rRNA processing as well as possible involvement in the heat shock/stress response will be examined. Finally, structural studies will define an evolutionarily conserved U14 secondary structure, determine those U14/18s rRNA sequences involved in intermolecular hybridization, and characterize the U14-associated proteins of a putative U14 ribonucleoprotein complex. Results from these studies will lead to a better understanding of the structure/function relationships of this unique and evolutionarily important eukaryotic lmwRNA.***//