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

AUTOR(ES)

Lange, Thilo Sascha

FONTE

The American Society for Cell Biology

RESUMO

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 laevis oocyte 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.

Documentos Relacionados

• In Vitro Assembly of Human H/ACA Small Nucleolar RNPs Reveals Unique Features of U17 and Telomerase RNAs
• Nucleolar Localization Elements of Xenopus laevis U3 Small Nucleolar RNA
• A Box H/ACA Small Nucleolar RNA-Like Domain at the Human Telomerase RNA 3′ End
• Nuclear Retention Elements of U3 Small Nucleolar RNA
• Architecture and assembly of mammalian H/ACA small nucleolar and telomerase ribonucleoproteins