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)

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

Although mechanisms for protein homeostasis in the cytosol have been studied extensively, those in the nucleus remain largely unknown. Here, we identified that a protein complex mediates export of polyubiquitinated proteins from the nucleus to the cytosol. UBIN, a ubiquitin-associated (UBA) domain-containing protein, shuttled between the nucleus and the cytosol in a CRM1-dependent manner, despite the lack of intrinsic nuclear export signal (NES). Instead, the UBIN binding protein polyubiquitinated substrate transporter (POST) harboring an NES shuttled UBIN through nuclear pores. UBIN bound to polyubiquitin chain through its UBA domain, and the UBIN-POST complex exported them from the nucleus to the cytosol. Ubiquitinated proteins accumulated in the cytosol in response to proteasome inhibition, whereas cotreatment with CRM1 inhibitor led to their accumulation in the nucleus. Our results suggest that ubiquitinated proteins are exported from the nucleus to the cytosol in the UBIN-POST complex-dependent manner for the maintenance of nuclear protein homeostasis.
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PMID:Nuclear export of ubiquitinated proteins via the UBIN-POST system. 2966 34