• IMMUNE NETWORK
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• v.22 no.3
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• pp.28.1-28.11
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• 2022

The 26S proteasome irreversibly hydrolyzes polyubiquitylated substrates to maintain protein homeostasis; it also regulates immune responses by generating antigenic peptides. An alternative form of the 26S proteasome is the immunoproteasome, which contains substituted catalytic subunits (β1i/PSMB9, β2i/PSMB10, and β5i/PSMB8) instead of constitutively expressed counterparts (β1/PSMB6, β2/PSMB7, and β5/PSMB5). The immunoproteasome expands the peptide repertoire presented on MHC class I molecules. However, how its activity changes in this context is largely elusive, possibly due to the lack of a standardized methodology to evaluate its specific activity. Here, we describe an assay protocol that measures the immunoproteasome activity of whole-cell lysates using commercially available fluorogenic peptide substrates. Our results showed that the most accurate assessment of immunoproteasome activity could be achieved by combining β5i-targeting substrate Ac-ANW-AMC and immunoproteasome inhibitor ONX-0914. This simple and reliable protocol may contribute to future studies of immunoproteasomes and their pathophysiological roles during viral infection, inflammation, and tumorigenesis.

• YAKHAK HOEJI
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• v.55 no.6
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• pp.466-472
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• 2011

NF-E2-related factor 2 (Nrf2), a master regulator of antioxidant genes in animals, has been associated with the resistance of cancer cells to several cytotoxic chemotherapeutics. Bortezomib, a reversible inhibitor of the 26S proteasome, is a novel class anti-cancer therapeutics approved for the treatment of refractory multiple myeloma. However, the molecular mechanism of drug-resistance remains elusive. In the present study, bortezomib sensitivity has been investigated in Nrf2 knockdown ovarian cancer cells. When Nrf2 expression is stably repressed using interfering RNA expression, bortezomib-induced apoptosis and cell death were significantly enhanced compared to nonspecific RNA control cells. Knockdown cells showed elevated expression in the catalytic subunit PSMB5, PSMB6, and PSMB7 compared to the control, and failed to induce heme oxygenase-1 expression following bortezomib treatment. These indicate that differential proteasome levels and altered expression of stress-response genes could be underlying mechanisms of bortezomib sensitization in Nrf2-inhibited ovarian cancer cells.

• YAKHAK HOEJI
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• v.54 no.6
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• pp.481-487
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• 2010

The proteasome plays a major role in the degradation of abnormal proteins within the cell. Therefore, repressed proteasome function is accepted as one of factors contributing the pathogenesis of multiple degenerative diseases. In the present study, we have observed that xanthohumol C, which is one of prenylated flavonoids from hops, increases the expression of the proteasome subunits through the Nrf2 pathway. Treatment of murine renal epithelial TCMK-1 cells with xanthohumol C and its methoxymethoxy-derivative elevated the expression of the Antioxidant Response Element (ARE)-driven reporter gene, as well as Nrf2-target genes including NAD(P)H: quinoneoxidoreductaes 1 (Nqo1). Transcript levels for the catalytic subunits of the proteasome Psmb5 and Psmb6 were increased by these compounds. The activation of the psmb5 promoter by xanthohumol C was abolished when the ARE in this promoter was mutated, indicating that proteasome induction was mediated by the Nrf2-ARE pathway. These results suggest that xanthohumol compounds from hops have a potential benefit on various oxidative stress-associated human diseases through the induction of the proteasome.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.135.2-135.2
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• 2011

The goal of this study is the derivation of priority for business in the areas of green energy technologies. In this paper, we calculated the importance weights of impact factors using the AHP (Analytic Hierarchy Process) method in order to derivation of priority to the green energy technologies business. AHP is a useful method for evaluating multi-criteria decision making problems. To apply the AHP method, specialists for the assessment have been identified by using the concept of 'plan, do, see' and the decision-making hierarchy was established. We selected 5 criteria and 16 sub-criteria for impact factors by brainstorming. According to the result in this study, the most important impact factor is the possibility of commercialization, the second is the possibility of developing the fundamental technology, and the third is the possibility of convergence technology.

• The Journal of Internal Korean Medicine
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• v.20 no.1
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• pp.198-209
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• 1999

A thrombus is a mass formed from the constituents of the blood within the vessels or the heart during life. The process of its formation is known as thrombosis, It has been generally accepted that Holotrichia is an useful medicine for thrombosis. The rate of fibrinolysis of Holotrichia extracts increase as incubation times. Especially 52 days, the effect on the extracts has an maximum increased fibrinolytic activity, Heat-and-pH-stability of the extract on fibrinolysis is relative to temperature, At $37^{\circ}C$, it has activating effect between pH 4 and pH 12. At higher temperature, especially $80^{\circ}C$, an excessive increase in temperature has a deactivating effect on the extracts. Optimal pH of the extract on fibrinolysis is between pH 7.0 and pH 8.5, it is effective within a relatively broad pH range. In experiments of various inhibitors of Holotrichia extracts fibrinolytic activity, there are strong inhibitive effect on SBTI and Aprotinin, and a few inhibitive effect on DFP and t-AMCHA, no effect on PSMB and TLCK. Holotrichia extracts mixing with fibrinogen are observed Electron microscopy. it shows partially erosive-shaped fibrinolytic activity. In a SDS-PAGE of the extract having the fibrinolytic activity, three bands are found, protein 1, 2 and 3 having a molecular weight of 30,000, 45,000 and 60,000 Dalton.