scholarly journals Multiple conserved segments of E1 small nucleolar RNA are involved in the formation of a ribonucleoprotein particle in frog oocytes

2000 ◽  
Vol 348 (3) ◽  
pp. 517-524 ◽  
Author(s):  
Donald D. RUHL ◽  
Mary Ellen PUSATERI ◽  
George L. ELICEIRI
Keyword(s):  
Gel Electrophoresis ◽  
Nucleolar Localization ◽  
Nucleotide Substitutions ◽  
Small Nucleolar Rna ◽  
Conserved Sequences ◽  
Exogenous Rna ◽  
Evolutionarily Conserved ◽  
Substitution Mutations ◽  
The Stability ◽  
Nucleolar Rna

E1/U17 small nucleolar RNA (snoRNA) is a box H/ACA snoRNA. To identify E1 RNA elements required for its assembly into a ribonucleoprotein (RNP) particle, we have made substitution mutations in evolutionarily conserved sequences and structures of frog E1 RNA. After E1 RNA was injected into the nucleus of frog oocytes, assembly of this exogenous RNA into an RNP was monitored by non-denaturing gel electrophoresis. Unexpectedly, nucleotide substitutions in many phylogenetically conserved segments of E1 RNA produced RNPs with abnormal gel-electrophoresis patterns. These RNA segments were at least nine conserved sequences and an apparently conserved structure. In another region needed for RNP formation, the requirement may be sequence(s) and/or structure. Base substitutions in each of these and in one additional conserved E1 RNA segment reduced the stability of this snoRNA in frog oocytes. Nucleolar localization was assayed by fluorescence microscopy after injection of fluorescein-labelled RNA. The H box (ANANNA) and the ACA box are both needed for efficient nucleolar localization of frog E1 RNA.

scholarly journals Nucleolar Localization Elements of Xenopus laevis U3 Small Nucleolar RNA

1998 ◽  
Vol 9 (10) ◽  
pp. 2973-2985 ◽  
Author(s):  
Thilo Sascha Lange ◽  
Michael Ezrokhi ◽  
Anton V. Borovjagin ◽  
Rafael Rivera-León ◽  
Melanie T. North ◽  
...  
Keyword(s):  
Xenopus Laevis ◽  
Hinge Region ◽  
Nucleolar Localization ◽  
Rrna Processing ◽  
Small Nucleolar Rna ◽  
Critical Elements ◽  
U3 Snorna ◽  
External Transcribed Spacer ◽  
Localization Elements ◽  
Nucleolar Rna

The Nucleolar Localization Elements (NoLEs) of Xenopus laevis U3 small nucleolar RNA (snoRNA) have been defined. Fluorescein-labeled wild-type U3 snoRNA injected intoXenopus oocyte nuclei localized specifically to nucleoli as shown by fluorescence microscopy. Injection of mutated U3 snoRNA revealed that the 5′ region containing Boxes A and A′, known to be important for rRNA processing, is not essential for nucleolar localization. Nucleolar localization of U3 snoRNA was independent of the presence and nature of the 5′ cap and the terminal stem. In contrast, Boxes C and D, common to the Box C/D snoRNA family, are critical elements for U3 localization. Mutation of the hinge region, Box B, or Box C′ led to reduced U3 nucleolar localization. Results of competition experiments suggested that Boxes C and D act in a cooperative manner. It is proposed that Box B facilitates U3 snoRNA nucleolar localization by the primary NoLEs (Boxes C and D), with the hinge region of U3 subsequently base pairing to the external transcribed spacer of pre-rRNA, thus positioning U3 snoRNA for its roles in rRNA processing.

The multifunctional RNase XRN2

2013 ◽  
Vol 41 (4) ◽  
pp. 825-830 ◽  
Author(s):  
Takashi S. Miki ◽  
Helge Großhans
Keyword(s):  
Small Nucleolar Rna ◽  
Cellular Processes ◽  
Evolutionarily Conserved ◽  
Mrna Precursor ◽  
Nucleolar Rna ◽  
Precursor Mrna

Different classes of RNA function in various cellular processes, and their biogenesis and turnover involve diverse RNases for processing and degradation. XRN2 is a 5′→3′ exoribonuclease that is evolutionarily conserved in eukaryotes. It is predominantly localized in the nucleus and recognizes single-stranded RNA with a 5′-terminal monophosphate to degrade it processively to mononucleotides. In the present paper, we review functions of XRN2 and its cofactors in maturation, surveillance and activity control of several classes of RNA such as pre-mRNA (precursor mRNA), rRNA and snoRNA (small nucleolar RNA).

scholarly journals Box H and Box ACA Are Nucleolar Localization Elements of U17 Small Nucleolar RNA

1999 ◽  
Vol 10 (11) ◽  
pp. 3877-3890 ◽  
Author(s):  
Thilo Sascha Lange ◽  
Michael Ezrokhi ◽  
Francesco Amaldi ◽  
Susan A. Gerbi
Keyword(s):  
Adverse Effect ◽  
Fluorescence Microscopy ◽  
Nucleolar Localization ◽  
Rrna Processing ◽  
Base Pairing ◽  
Small Nucleolar Rna ◽  
Family Function ◽  
Tail Structure ◽  
Localization Elements ◽  
Nucleolar Rna

The nucleolar localization elements (NoLEs) of U17 small nucleolar RNA (snoRNA), which is essential for rRNA processing and belongs to the box H/ACA snoRNA family, were analyzed by fluorescence microscopy. Injection of mutant U17 transcripts into Xenopus laevisoocyte nuclei revealed that deletion of stems 1, 2, and 4 of U17 snoRNA reduced but did not prevent nucleolar localization. The deletion of stem 3 had no adverse effect. Therefore, the hairpins of the hairpin–hinge–hairpin–tail structure formed by these stems are not absolutely critical for nucleolar localization of U17, nor are sequences within stems 1, 3, and 4, which may tether U17 to the rRNA precursor by base pairing. In contrast, box H and box ACA are major NoLEs; their combined substitution or deletion abolished nucleolar localization of U17 snoRNA. Mutation of just box H or just the box ACA region alone did not fully abolish the nucleolar localization of U17. This indicates that the NoLEs of the box H/ACA snoRNA family function differently from the bipartite NoLEs (conserved boxes C and D) of box C/D snoRNAs, where mutation of either box alone prevents nucleolar localization.

Small nucleolar RNA host genes promoting epithelial–mesenchymal transition lead cancer progression and metastasis

IUBMB Life ◽  
2021 ◽  
Author(s):  
Alessio Biagioni ◽  
Shima Tavakol ◽  
Nooshin Ahmadirad ◽  
Masoumeh Zahmatkeshan ◽  
Lucia Magnelli ◽  
...  
Keyword(s):  
Cancer Progression ◽  
Epithelial Mesenchymal Transition ◽  
Small Nucleolar Rna ◽  
Mesenchymal Transition ◽  
Nucleolar Rna ◽  
Host Genes

Distribution of U3 small nucleolar RNA and fibrillarin during early embryogenesis in Caenorhabditis elegans

Biochimie ◽  
2008 ◽  
Vol 90 (6) ◽  
pp. 898-907 ◽  
Author(s):  
Yumi Sasano ◽  
Yusuke Hokii ◽  
Kunio Inoue ◽  
Hiroshi Sakamoto ◽  
Chisato Ushida ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Early Embryogenesis ◽  
Small Nucleolar Rna ◽  
Nucleolar Rna
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