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)

Hibernation torpor provides an excellent model of natural tolerance to ischemia. We have previously shown that massive global SUMOylation occurs during hibernation torpor in ground squirrels. We have also shown that overexpression of Ubc9, SUMO-1, or SUMO-2/3 provides protection against ischemic damage in cell lines and cortical neurons exposed to oxygen/glucose deprivation, and in mice exposed to middle cerebral artery occlusion. We have now extended our study to other Ubiquitin-Like-Modifiers (ULMs), which have multiple cellular functions during stress, in order to assess the possibility that they also have roles in tolerance to ischemia. We found that not only SUMO conjugation, but also global protein conjugation by other ULMs including NEDD8, ISG15, UFM1 and FUB1 were significantly increased in the brains of hibernating ground squirrels during torpor. By means of miRNA microarrays of ground squirrel brain samples (from active and torpor phase) we found that the miR-200 family (miR-200a,b,c/miR-141/miR-429) and the miR-182 family (miR-182/miR-183/miR-96) were among the most consistently depressed miRNAs in the brain during the torpor phase as compared to active animals. In addition, we showed that these miRNAs are involved in the expression of various ULM proteins and their global conjugation to proteins. We observed that inhibition of the miR-200 family and/or miR-182 family miRNA activities in SHSY5Y cells increases global protein conjugation by the above ULMs and makes these cells more tolerant to OGD-induced cell death. This is the first report to describe that the natural tolerance to brain ischemia in hibernators is linked to regulation by microRNAs of a broad range of ubiquitin-like modifiers.
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PMID:Global protein conjugation by ubiquitin-like-modifiers during ischemic stress is regulated by microRNAs and confers robust tolerance to ischemia. 2309 87

Ubiquitin-like proteins (Ubl's) are conjugated to target proteins or lipids to regulate their activity, stability, subcellular localization, or macromolecular interactions. Similar to ubiquitin, conjugation is achieved through a cascade of activities that are catalyzed by E1 activating enzymes, E2 conjugating enzymes, and E3 ligases. In this review, we will summarize structural and mechanistic details of enzymes and protein cofactors that participate in Ubl conjugation cascades. Precisely, we will focus on conjugation machinery in the SUMO, NEDD8, ATG8, ATG12, URM1, UFM1, FAT10, and ISG15 pathways while referring to the ubiquitin pathway to highlight common or contrasting themes. We will also review various strategies used to trap intermediates during Ubl activation and conjugation.
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PMID:Ubiquitin-like Protein Conjugation: Structures, Chemistry, and Mechanism. 2823 46

The key component in the UFM1 conjugation system, UFM1-binding and PCI domain-containing protein 1 (UFBP1), regulates many biological processes. Recently it has been shown that low UFBP1 protein level is associated with the worse outcome of gastric cancer patients. However, how it responses to the sensitivity of gastric cancer to chemotherapy drugs and the underlying molecular mechanism remain elusive. Here, we discovered that high UFBP1 expression increases the progression-free survival of advanced gastric cancer patients treated with platinum-based chemotherapy. Cell-line based studies unveiled that UFBP1 expression enhances while UFBP1 knockdown attenuates the sensitivity of gastric cancer cells to cisplatin. High-throughput SILAC-based quantitative proteomic analysis revealed that the protein level of aldo-keto reductase 1Cs (AKR1Cs) is significantly downregulated by UFBP1. Flow cytometry analysis showed that UFBP1 expression increases while UFBP1 knockdown reduces reactive oxygen species upon cisplatin treatment. We further disclosed that UFBP1 attenuates the gene expression of AKR1Cs and the transcription activity of the master oxidative stress-response transcription factor Nrf2 (nuclear factor erythroid-2-related factor 2). Detailed mechanistic studies manifested that UFBP1 promotes the formation of K48-linked polyubiquitin chains on Nrf2 and thus augments its proteasome-mediated degradation. Experiments using genetic depletion and pharmacological activation in vitro and in vivo demonstrated that UFBP1 enhances the sensitivity of gastric cancer cells to cisplatin through the Nrf2/AKR1C axis. Overall, this work discovered a novel prognostic biomarker for gastric cancer patients treated with platinum-based chemotherapy and elucidated the underlying molecular mechanism, which may benefit to future personalized chemotherapy.
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PMID:UFBP1, a key component in ufmylation, enhances drug sensitivity by promoting proteasomal degradation of oxidative stress-response transcription factor Nrf2. 3321 17