Hostname: page-component-cd9895bd7-lnqnp Total loading time: 0 Render date: 2024-12-19T02:09:46.375Z Has data issue: false hasContentIssue false
  • English
  • Français

Nucleolar localization elements in U8 snoRNA differ from sequences required for rRNA processing

Published online by Cambridge University Press:  01 July 1998

THILO SASCHA LANGE ,
ANTON V. BOROVJAGIN  and
SUSAN A. GERBI
THILO SASCHA LANGE
Affiliation:
Division of Biology and Medicine, Brown University, Providence, Rhode Island 02912, USA
ANTON V. BOROVJAGIN
Affiliation:
Division of Biology and Medicine, Brown University, Providence, Rhode Island 02912, USA
SUSAN A. GERBI
Affiliation:
Division of Biology and Medicine, Brown University, Providence, Rhode Island 02912, USA
Get access

Abstract

U8 small nucleolar RNA (snoRNA) is essential for metazoan ribosomal RNA (rRNA) processing in nucleoli. The sequences and structural features in Xenopus U8 snoRNA that are required for its nucleolar localization were analyzed. Fluorescein-labeled U8 snoRNA was injected into Xenopus oocyte nuclei, and fluorescence microscopy of nucleolar preparations revealed that wild-type Xenopus U8 snoRNA localized to nucleoli, regardless of the presence or nature of the 5′ cap on the injected U8 snoRNA. Nucleolar localization was observed when loops or stems in the 5′ portion of U8 that are critical for U8 snoRNA function in rRNA processing were mutated. Therefore, sites of interaction in U8 snoRNA that potentially tether it to pre-rRNA are not essential for nucleolar localization of U8. Boxes C and D are known to be nucleolar localization elements (NoLEs) for U8 snoRNA and other snoRNAs of the Box C/D family. However, the spatial relationship of Box C to Box D was not crucial for U8 nucleolar localization, as demonstrated here by deletion of sequences in the two stems that separate them. These U8 mutants can localize to nucleoli and function in rRNA processing as well. The single-stranded Cup region in U8, adjacent to evolutionarily conserved Box C, functions as a NoLE in addition to Boxes C and D. Cup is unique to U8 snoRNA and may help bind putative protein(s) needed for nucleolar localization. Alternatively, Cup may help to retain U8 snoRNA within the nucleolus.

Keywords

nucleolar localizationU8 small nucleolar RNA (snoRNA)Xenopus oocyte
Type
Research Article
Information
RNA , Volume 4 , Issue 7 , July 1998 , pp. 789 - 800
Copyright
© 1998 RNA Society

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)