• Journal of Microbiology and Biotechnology
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• v.31 no.9
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• pp.1305-1310
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• 2021

Shikimate is a key high-demand metabolite for synthesizing valuable antiviral drugs, such as the anti-influenza drug, oseltamivir (Tamiflu). Microbial-based strategies for shikimate production have been developed to overcome the unstable and expensive supply of shikimate derived from traditional plant extraction processes. In this study, a microbial cell factory using Corynebacterium glutamicum was designed to overproduce shikimate in a fed-batch culture system. First, the shikimate kinase gene (aroK) responsible for converting shikimate to the next step was disrupted to facilitate the accumulation of shikimate. Several genes encoding the shikimate bypass route, such as dehydroshikimate dehydratase (QsuB), pyruvate kinase (Pyk1), and quinate/shikimate dehydrogenase (QsuD), were disrupted sequentially. An artificial operon containing several shikimate pathway genes, including aroE, aroB, aroF, and aroG were overexpressed to maximize the glucose uptake and intermediate flux. The rationally designed shikimate-overproducing C. glutamicum strain grown in an optimized medium produced approximately 37.3 g/l of shikimate in 7-L fed-batch fermentation. Overall, rational cell factory design and culture process optimization for the microbial-based production of shikimate will play a key role in complementing traditional plant-derived shikimate production processes.

• Proceedings of the Microbiological Society of Korea Conference
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• 2005.05a
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• pp.176-176
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• 2005

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.201-202
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• 2005

• BMB Reports
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• v.49 no.2
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• pp.111-115
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• 2016

Caffeine has been proposed to have several beneficial effects on obesity and its related metabolic diseases; however, how caffeine affects adipocyte differentiation has not been elucidated. In this study, we demonstrated that caffeine suppressed 3T3-L1 adipocyte differentiation and inhibited the expression of CCAAT/enhancer binding protein (C/EBP)α and peroxisome proliferator-activated receptor (PPAR)γ, two main adipogenic transcription factors. Anti-adipogenic markers, such as preadipocyte secreted factor (Pref)-1 and Krüppel-like factor 2, remained to be expressed in the presence of caffeine. Furthermore, 3T3-L1 cells failed to undergo typical mitotic clonal expansion in the presence of caffeine. Investigation of hormonal signaling revealed that caffeine inhibited the activation of AKT and glycogen synthase kinase (GSK) 3 in a dose-dependent manner, but not extracellular signal-regulated kinase (ERK). Our data show that caffeine is an anti-adipogenic bioactive compound involved in the modulation of mitotic clonal expansion during adipocyte differentiation through the AKT/GSK3 pathway.

• The Korean Journal of Physiology and Pharmacology
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• v.9 no.5
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• pp.299-304
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• 2005

Cardiac hypertrophy contributes an increased risk to major cerebrovascular events. However, the molecular mechanisms underlying cerebrovascular dysfunction during cardiac hypertrophy have not yet been characterized. In the present study, we examined the molecular mechanism of isoproterenol (ISO)-evoked activation of Ras/Raf/MAPK pathways as well as PKA activity in cerebral artery of rabbits, and we also studied whether the activations of these signaling pathways were altered in cerebral artery, during ISO-induced cardiac hypertrophy compared to heart itself. The results show that the mRNA level of c-fos (not c-jun and c-myc) in heart and these genes in cerebral artery were considerably increased during cardiac hypertrophy. These results that the PKA activity and activations of Ras/Raf/ERK cascade as well as c-fos expression in rabbit heart during cardiac hypertrophy were consistent with previous reports. Interestingly, however, we also showed a novel finding that the decreased PKA activity might have differential effects on Ras and Raf expression in cerebral artery during cardiac hypertrophy. In conclusion, there are differences in molecular mechanisms between heart and cerebral artery during cardiac hypertrophy when stimulated with β2 adrenoreceptor (AR), suggesting a possible mechanism underlying cerebrovascular dysfunction during cardiac hypertrophy.

• Journal of Microbiology and Biotechnology
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• v.27 no.10
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• pp.1867-1876
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• 2017

Most of the biosynthetic pathways for secondary metabolites are influenced by carbon metabolism and supply of cytosolic NADPH. We engineered carbon distribution to the pentose phosphate pathway (PPP) and redesigned the host to produce high levels of NADPH and primary intermediates from the PPP. The main enzymes producing NADPH in the PPP, glucose 6-phosphate dehydrogenase (encoded by zwf1 and zwf2) and 6-phosphogluconate dehydrogenase (encoded by zwf3), were overexpressed with opc encoding a positive allosteric effector essential for Zwf activity in various combinations in Streptomyces lividans TK24. Most S. lividans transformants showed better cell growth and higher concentration of cytosolic NADPH than those of the control, and S. lividans TK24/pWHM3-Z23O2 containing zwf2+zwf3+opc2 showed the highest NADPH concentration but poor sporulation in R2YE medium. S. lividans TK24/pWHM3-Z23O2 in minimal medium showed the maximum growth (6.2 mg/ml) at day 4. Thereafter, a gradual decrease of biomass and a sharp increase of cytosolic NADPH and sedoheptulose 7-phosphate between days 2 and 4 and between days 1 and 3, respectively, were observed. Moreover, S. lividans TK24/pWHM3-Z23O2 produced 0.9 times less actinorhodin but 1.8 times more undecylprodigiosin than the control. These results suggested that the increased NADPH concentration and various intermediates from the PPP specifically triggered undecylprodigiosin biosynthesis that required many precursors and NADPH-dependent reduction reaction. This study is the first report on bespoke metabolic engineering of PPP routes especially suitable for producing secondary metabolites that need diverse primary precursors and NADPH, which is useful information for metabolic engineering in Streptomyces.

• Archives of Pharmacal Research
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• v.7 no.1
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• pp.65-68
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• 1984

Mechanism of the monoamine oxidase inhibition by tranylcypromine was studied in relation to its metabolism to reactive apecies. A metabolic study performed to collect general biotransformation pathway in rats provided GC/MS evidence for the detection of two new metabolites, N-acetyl and hydroxylated N-acetyltranylacypromine.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.214.4-215
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• 2003

In galactose metabolic pathway : there are three inborn metabolic disorders galactokinase deficiency (galactosemia type II), galactose-1-phosphate uridyl transferase(GALT) daficiency (galactosemia type I ), uridine diphosphate galactose-4-epimerase deficiency (galactosemia typeIII). Among these disorders GALT deficiency is the most severe and common. Infants with GALT deficiency fail to metabolize galactose-1-phosphate. As a consequence, galactose-1-phosphate and galactose are accumulated in blood in which GALS enzyme plays the role of a pathognomonic marker. (omitted)

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.05a
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• pp.73-73
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• 2002

Thioacetamide has been known to cause immune suppression. The object of the present study is to investigate the role of metabolic activation by flavin- containing monooxygenases (FMO) in thioacetamide-induced immune response. To determine whether the metabolites of thioacetamide produced by FMO causes the immunosuppression, methimazole (MMI), an FMO inhibitor, was used to block the FMO pathway.(omitted)

• KSBB Journal
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• v.32 no.3
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• pp.169-173
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• 2017

Butyric acid (C4 carboxylic acid) is used as an important compound in food, pharmaceutical, and chemical industries. Currently, butyric acid is mainly produced at the industrial scale through the petrochemical processes. Bio-based butyric acid has also gained attention, because the consumer prefers the food and pharmaceutical ingredients that are produced through fermentation. Clostridia is one of the well-known butyric acid producers, and massively engineered for enhanced production of butyric acid. In this paper, we reviewed the metabolic pathway of clostridia, especially Clostridium acetobutylicum and Clostridium tyrobutyricum, and summarized the metabolic engineering strategies of the strains for enhanced production of butyric acid.