Targeting vertebrate intron-encoded box C/D 2'-O-methylation guide RNAs into the Cajal body

Nucleic Acids Res. 2014 Jun;42(10):6616-29. doi: 10.1093/nar/gku287. Epub 2014 Apr 20.

Abstract

Post-transcriptional pseudouridylation and 2'-O-methylation of splicesomal small nuclear ribonucleic acids (snRNAs) is mediated by box H/ACA and box C/D small Cajal body (CB)-specific ribonucleoproteins (scaRNPs), respectively. The WD-repeat protein 79 (WDR79) has been proposed to interact with both classes of modification scaRNPs and target them into the CB. The box H/ACA scaRNAs carry the common CAB box motif (consensus, ugAG) that is required for both WDR79 binding and CB-specific accumulation. Thus far, no cis-acting CB-localization element has been reported for vertebrate box C/D scaRNAs. In this study, systematic mutational analysis of the human U90 and another newly identified box C/D scaRNA, mgU2-47, demonstrated that the CB-specific accumulation of vertebrate intron-encoded box C/D scaRNAs relies on GU- or UG-dominated dinucleotide repeat sequences which are predicted to form the terminal stem-loop of the RNA apical hairpin. While the loop nucleotides are unimportant, the adjacent terminal helix that is composed mostly of consecutive G.U and U.G wobble base-pairs is essential for CB-specific localization of box C/D scaRNAs. Co-immunoprecipitation experiments confirmed that the newly identified CB localization element, called the G.U/U.G wobble stem, is crucial for in vivo association of box C/D scaRNPs with WDR79.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Coiled Bodies / metabolism*
  • HeLa Cells
  • Humans
  • Introns
  • Molecular Chaperones
  • Nucleic Acid Conformation
  • Proteins / metabolism
  • RNA, Guide / chemistry*
  • RNA, Guide / metabolism*
  • RNA, Small Nuclear / chemistry
  • RNA, Small Nuclear / metabolism
  • RNA, Small Nucleolar / chemistry*
  • RNA, Small Nucleolar / metabolism*
  • Repetitive Sequences, Nucleic Acid
  • Telomerase

Substances

  • Molecular Chaperones
  • Proteins
  • RNA, Guide
  • RNA, Small Nuclear
  • RNA, Small Nucleolar
  • Telomerase
  • WRAP53 protein, human