Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P62988 (Ubiquitin)
 4,326 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Although there is a binding site on the proteasome for the polyubiquitin chains attached to degradation substrates by the ubiquitination machinery, it is currently unclear whether in vivo the activities of the ubiquitination machinery and the proteasome are coupled. Here we show that two human homologs of the yeast ubiquitin-like Dsk2 protein, hPLIC-1 and hPLIC-2, physically associate with both proteasomes and ubiquitin ligases in large complexes. Overexpression of hPLIC proteins interferes with the in vivo degradation of two unrelated ubiquitin-dependent proteasome substrates, p53 and IkappaBalpha, but not a ubiquitin-independent substrate. Our findings raise the possibility that the hPLIC proteins, and possibly related ubiquitin-like family members, may functionally link the ubiquitination machinery to the proteasome to affect in vivo protein degradation.
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PMID:The hPLIC proteins may provide a link between the ubiquitination machinery and the proteasome. 1098 87

Ubiquitin is one of phylogenetically well-conserved proteins in all eukaryotes. Ubiquitin-dependent modification of protein contributes to fine regulation of cellular biological processes. Using large-scale screening of human bone marrow stromal cell (BMSC) cDNA library, we isolated a full-length cDNA of 1352 bp encoding 380 amino acids with a ubiquitin domain (UBQ), which was designed as bone marrow stromal cell-derived ubiquitin-like protein (BMSC-UbP). In addition to UBQ domain at its N-terminus, BMSC-UbP also possesses a ubiquitin-associated domain at its C-terminus, sharing moderate homology to some ubiquitin-like proteins such as UBIN, Chap1, and ubiquilin. BMSC-UbP localizes at chromosome 15q22.3-q23 as confirmed by blast search in human genome. BMSC-UbP mRNA is widely expressed in human multiple tissues and various tumor cell lines. Moreover, BMSC-UbP mRNA decreased in BMSC stimulated with PMA and increased in HL60 cells stimulated with LPS, suggesting that BMSC-UbP might play roles in regulation of BMSC function or cell differentiation through an evocator- and cell-specific pattern.
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PMID:Cloning and identification of a novel ubiquitin-like protein, BMSC-UbP, from human bone marrow stromal cells. 1264 19