Proteomic analysis of human Nop56p-associated pre-ribosomal ribonucleoprotein complexes. Possible link between Nop56p and the nucleolar protein treacle responsible for Treacher Collins syndrome.
Nop56p is a component of the box C/D small nucleolar ribonucleoprotein complexes that direct 2'-O-methylation of pre-rRNA during its maturation. Genetic analyses in yeast have shown that Nop56p plays important roles in the early steps of pre-rRNA processing. However, its precise function remains elusive, especially in higher eukaryotes. Here we ... describe the proteomic characterization of human Nop56p (hNop56p)-associated pre-ribosomal ribonucleoprotein complexes. Mass spectrometric analysis of purified pre-ribosomal ribonucleoprotein complexes identified 61 ribosomal proteins, 16 trans-acting factors probably involved in ribosome biogenesis, and 29 proteins whose function in ribosome biogenesis is unknown. Identification of pre-rRNA species within hNop56p-associated pre-ribosomal ribonucleoprotein complexes, coupled with the known functions of yeast orthologs of the probable trans-acting factors identified in human, demonstrated that hNop56p functions in the early to middle stages of 60 S subunit synthesis in human cells. Interestingly, the nucleolar phosphoprotein treacle, which is responsible for the craniofacial disorder associated with Treacher Collins syndrome, was found to be a constituent of hNop56p-associated pre-rRNP complexes. The association of hNop56p and treacle within the complexes was independent of rRNA integrity, indicating a direct interaction. In addition, the protein compositions of the treacle-associated and hNop56p-associated pre-ribosomal ribonucleoprotein complexes were very similar, suggesting functional similarities between these two complexes with respect to ribosome biogenesis in human cells.
Mesh Terms:
Amino Acid Motifs, Blotting, Northern, Cell Line, Cell Nucleolus, Cell Nucleus, Electrophoresis, Polyacrylamide Gel, Epitopes, Humans, Immunohistochemistry, Mandibulofacial Dysostosis, Mass Spectrometry, Models, Genetic, Nuclear Proteins, Phosphoproteins, Precipitin Tests, Protein Binding, Protein Structure, Tertiary, Proteome, RNA, Ribosomal, Ribonucleases, Ribonucleoproteins, Ribosomes, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Transfection
Amino Acid Motifs, Blotting, Northern, Cell Line, Cell Nucleolus, Cell Nucleus, Electrophoresis, Polyacrylamide Gel, Epitopes, Humans, Immunohistochemistry, Mandibulofacial Dysostosis, Mass Spectrometry, Models, Genetic, Nuclear Proteins, Phosphoproteins, Precipitin Tests, Protein Binding, Protein Structure, Tertiary, Proteome, RNA, Ribosomal, Ribonucleases, Ribonucleoproteins, Ribosomes, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Transfection
J. Biol. Chem.
Date: Sep. 05, 2003
PubMed ID: 12777385
View in: Pubmed Google Scholar
Download Curated Data For This Publication
60464
Switch View:
- Interactions 71