Identification of proteassemblin, a mammalian homologue of the yeast protein, Ump1p, that is required for normal proteasome assembly

Mol Cell Biol Res Commun. 2000 Apr;3(4):212-7. doi: 10.1006/mcbr.2000.0213.

Abstract

We have identified a mammalian homologue of yeast Ump1p by searching for similar proteins in human and mouse expressed sequence tag (EST) databases. Ump1p is an accessory protein that is required for normal proteasome assembly in yeast (1). A mammalian homologue, which we refer to as "proteassemblin," is a constituent of proteasome assembly intermediates (preproteasomes), but not fully assembled 20S proteasomes, as is Ump1p in yeast. We also provide evidence that proteassemblin is a constituent of pre-immunoproteasomes that contain the precursor of the interferon-gamma-inducible subunit LMP2. By analogy with Ump1p, we hypothesize that proteassemblin is required for normal mammalian proteasome assembly.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Blotting, Western
  • Cloning, Molecular
  • Cysteine Endopeptidases / biosynthesis
  • Cysteine Endopeptidases / chemistry
  • Cysteine Endopeptidases / metabolism*
  • Electrophoresis, Gel, Two-Dimensional
  • Expressed Sequence Tags
  • Fungal Proteins / chemistry*
  • Humans
  • Isoelectric Point
  • Mice
  • Molecular Chaperones / chemistry*
  • Molecular Chaperones / genetics*
  • Molecular Chaperones / metabolism*
  • Molecular Sequence Data
  • Molecular Weight
  • Multienzyme Complexes / biosynthesis
  • Multienzyme Complexes / chemistry
  • Multienzyme Complexes / metabolism*
  • Proteasome Endopeptidase Complex
  • Protein Precursors / chemistry
  • Protein Precursors / genetics
  • Protein Precursors / metabolism
  • Proteins / chemistry
  • Proteins / genetics
  • Proteins / metabolism
  • RNA, Messenger / metabolism
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Sequence Alignment

Substances

  • Fungal Proteins
  • Molecular Chaperones
  • Multienzyme Complexes
  • Protein Precursors
  • Proteins
  • RNA, Messenger
  • Recombinant Fusion Proteins
  • proteasome maturation protein
  • proteassemblin
  • LMP-2 protein
  • Cysteine Endopeptidases
  • Proteasome Endopeptidase Complex