Identification of proteassemblin, a mammalian homologue of the yeast protein, Ump1p, that is required for normal proteasome assembly.
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.
Griffin
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William S. Rowe Division of Rheumatology, Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, Ohio 45229-3039, USA. grift0@chmcc.org
Slack
J P
JP
McCluskey
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Monaco
J J
JJ
Colbert
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D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D003001:Cloning, Molecular; D003546:Cysteine Endopeptidases / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D015180:Electrophoresis, Gel, Two-Dimensional; D020224:Expressed Sequence Tags; D005656:Fungal Proteins / Q000737:chemistry*; D006801:Humans; D007526:Isoelectric Point; D051379:Mice; D018832:Molecular Chaperones / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009097:Multienzyme Complexes / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex; D011498:Protein Precursors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011506:Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment
D005656:Fungal Proteins; D018832:Molecular Chaperones; D009097:Multienzyme Complexes; D011498:Protein Precursors; D011506:Proteins; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; C110856:proteasome maturation protein; C413862:proteassemblin; C071313:LMP-2 protein; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex