Nob1p, a New Essential Protein, Associates With the 26S Proteasome of Growing Saccharomyces Cerevisiae Cells

Gene. 2000 Feb 8;243(1-2):37-45. doi: 10.1016/s0378-1119(99)00566-1.


Nob1p, which interacts with Nin1p/Rpn12, a subunit of the 19S regulatory particle (RP) of the yeast 26S proteasome, has been identified by two-hybrid screening. NOB1 was found to be an essential gene, encoding a protein of 459 amino acid residues. Nob1p was detected in growing cells but not in cells in the stationary phase. During the transition to the stationary phase, Nob1p was degraded, at least in part, by the 26S proteasome. Nob1p was found only in proteasomal fractions in a glycerol gradient centrifugation profile and immuno-coprecipitated with Rpt1, which is an ATPase component of the yeast proteasomes. These results suggest that association of Nob1p with the proteasomes is essential for the function of the proteasomes in growing cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carrier Proteins / genetics*
  • Carrier Proteins / metabolism
  • DNA, Fungal / genetics
  • DNA, Fungal / isolation & purification
  • Electrophoresis, Polyacrylamide Gel
  • Fungal Proteins / genetics*
  • Fungal Proteins / metabolism
  • Gene Expression Regulation, Developmental
  • Gene Expression Regulation, Fungal
  • Genes, Essential / genetics
  • Genes, Fungal / genetics
  • Nuclear Proteins
  • Peptide Hydrolases / metabolism*
  • Proteasome Endopeptidase Complex*
  • Protein Binding
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae / growth & development
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins*
  • Two-Hybrid System Techniques


  • Carrier Proteins
  • DNA, Fungal
  • Fungal Proteins
  • NOB1 protein, S cerevisiae
  • Nuclear Proteins
  • RPN12 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Peptide Hydrolases
  • Proteasome Endopeptidase Complex
  • ATP dependent 26S protease