Alternative titles; symbols
HGNC Approved Gene Symbol: RRP1
Cytogenetic location: 21q22.3 Genomic coordinates (GRCh38) : 21:43,789,577-43,805,293 (from NCBI)
NOP52 is one of several proteins involved in the late processing steps of ribosome biogenesis (Savino et al., 1999).
Using mouse Nnp1 to screen a human fetal kidney cDNA library, Jansen et al. (1997) cloned NNP1. The deduced 461-amino acid protein has a calculated molecular mass of 52 kD. It contains simian virus 40-type and bipartite nuclear localization signals within its C-terminal region. Northern blot analysis detected a 2.0-kb transcript in all fetal and adult tissues examined.
Using serum containing autoantibodies recognizing a 52-kD nucleolar protein to screen a HeLa cell cDNA expression library, Savino et al. (1999) cloned NOP52. In addition to the 2 C-terminal nuclear localization signals, NOP52 has 4 coiled-coil domains in its C-terminal half. It shares 36% amino acid identity with yeast Rrp1, a protein involved in processing and maturation of 27S rRNA. Indirect immunofluorescence localized NOP52 to nucleoli, with more intense staining at the nucleolar periphery than internal regions. From prophase to late telophase of mitosis, NOP52 localized to the periphery of chromosomes.
Savino et al. (1999) found that, in nucleoli, NOP52 was excluded from rRNA transcription sites, accumulated in the granular external domain, and mainly colocalized with nucleolar proteins involved in late rRNA processing steps. During rebuilding of the nucleolus at the end of mitosis, nucleolar proteins assembled in sequential order, mainly via the prenucleolar body pathway. NOP52 assembled after fibrillarin (FBL; 134795) and nucleolin (NCL; 164035), simultaneously with B23 (NPM1; 164040) and POP1 (602486), the only protein not found in prenucleolar bodies, and prior to MKI67 (176741).
Jansen et al. (1997) determined that the NNP1 gene contains 14 exons and spans 15 kb.
By genomic sequence analysis, Jansen et al. (1997) mapped the NNP1 gene to chromosome 21q33.3, 25 kb distal to the cystatin B gene (CSTB; 601145).
Jansen, E., Meulemans, S. M. P., Orlans, I. C. R., Van de Ven, W. J. M. The NNP-1 gene (D21S2056E), which encodes a novel nuclear protein, maps in close proximity to the cystatin B gene within the EPM1 and APECED critical region on 21q22.3. Genomics 42: 336-341, 1997. [PubMed: 9192856] [Full Text: https://doi.org/10.1006/geno.1997.4755]
Savino, T. M., Bastos, R., Jansen, E., Hernandez-Verdun, D. The nucleolar antigen Nop52, the human homologue of the yeast ribosomal RNA processing RRP1, is recruited at late stages of nucleologenesis. J. Cell Sci. 112: 1889-1900, 1999. [PubMed: 10341208] [Full Text: https://doi.org/10.1242/jcs.112.12.1889]