Isolation and sequencing of NOP1. A yeast gene encoding a nucleolar protein homologous to a human autoimmune antigen

J Biol Chem. 1990 Feb 5;265(4):2209-15.


We have identified the gene for the yeast nucleolar protein p38 and deduced the primary structure of p38 from its sequence. We propose the name NOP1 (nucleolar protein 1) for this gene. NOP1 encodes a 327 amino acid protein of 34,470 daltons and is flanked by potential promoter and polyadenylation sequences. Blot analyses indicate that the mRNA transcribed from NOP1 is approximately 1.3 kilobases in size and that there is one NOP1 gene per haploid genome. The amino-terminal sequence of p38 is homologous with the 31 known amino-terminal residues of the autoimmune antigen fibrillarin, confirming the previously observed similarity between p38 and this mammalian nucleolar protein. Consistent with this, p38 cross-reacts with serum from a patient with the autoimmune disease scleroderma. A putative nuclear localization signal can be identified in p38. Interestingly, a repetitive amino acid sequence motif begins near the amino terminus of p38. This motif is approximately 80 residues long, is rich in glycine and arginine, and shows striking sequence homology to mammalian nucleolins and certain nucleic acid binding proteins.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Autoantigens / genetics*
  • Base Sequence
  • Cell Nucleolus / metabolism*
  • Cross Reactions
  • Cyanogen Bromide
  • DNA, Fungal / genetics*
  • DNA, Fungal / isolation & purification
  • Fungal Proteins / genetics*
  • Genes*
  • Genes, Fungal*
  • Humans
  • Molecular Sequence Data
  • Nuclear Proteins / genetics*
  • Oligonucleotide Probes / chemical synthesis
  • Peptide Mapping
  • Ribonucleoproteins, Small Nucleolar*
  • Saccharomyces cerevisiae Proteins*
  • Sequence Homology, Nucleic Acid


  • Autoantigens
  • DNA, Fungal
  • Fungal Proteins
  • NOP1 protein, S cerevisiae
  • Nuclear Proteins
  • Oligonucleotide Probes
  • Ribonucleoproteins, Small Nucleolar
  • Saccharomyces cerevisiae Proteins
  • Cyanogen Bromide

Associated data

  • GENBANK/J05230