A conserved WD40 protein binds the Cajal body localization signal of scaRNP particles

Mol Cell. 2009 Apr 10;34(1):47-57. doi: 10.1016/j.molcel.2009.02.020. Epub 2009 Mar 12.


Small Cajal body (CB)-specific RNPs (scaRNPs) function in posttranscriptional modification of small nuclear (sn)RNAs. An RNA element, the CAB box, facilitates CB localization of H/ACA scaRNPs. Using a related element in Drosophila C/D scaRNAs, we purified a fly WD40 repeat protein that UV crosslinks to RNA in a C/D CAB box-dependent manner and associates with C/D and mixed domain C/D-H/ACA scaRNAs. Its human homolog, WDR79, associates with C/D, H/ACA, and mixed domain scaRNAs, as well as with telomerase RNA. WDR79's binding to human H/ACA and mixed domain scaRNAs is CAB box dependent, and its association with mixed domain RNAs also requires the ACA motif, arguing for additional interactions of WDR79 with H/ACA core proteins. We demonstrate a requirement for WDR79 binding in the CB localization of a scaRNA. This and other recent reports establish WDR79 as a central player in the localization and processing of nuclear RNPs.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Motifs
  • Animals
  • Base Sequence
  • Cell Line
  • Chromatography, Affinity
  • Coiled Bodies / metabolism*
  • Coiled Bodies / ultrastructure
  • Drosophila Proteins / analysis
  • Drosophila Proteins / chemistry
  • Drosophila Proteins / metabolism*
  • Drosophila melanogaster / genetics
  • Drosophila melanogaster / metabolism*
  • HeLa Cells
  • Humans
  • Molecular Sequence Data
  • Nucleic Acid Conformation
  • RNA-Binding Proteins / analysis
  • RNA-Binding Proteins / chemistry
  • RNA-Binding Proteins / metabolism*
  • Recombinant Fusion Proteins / analysis
  • Regulatory Sequences, Ribonucleic Acid
  • Ribonucleoproteins / analysis
  • Ribonucleoproteins / metabolism*
  • Sequence Alignment


  • Drosophila Proteins
  • RNA-Binding Proteins
  • Recombinant Fusion Proteins
  • Regulatory Sequences, Ribonucleic Acid
  • Ribonucleoproteins
  • WDR79 protein, Drosophila

Associated data

  • GENBANK/BK006790
  • GENBANK/BK006791
  • GENBANK/BK006792
  • GENBANK/BK006793