• Journal of Microbiology and Biotechnology
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• v.5 no.4
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• pp.200-205
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• 1995

Nutritional factors regulating the morphological differentiation and physiological differentiation of Streptomyces exfoliatus SMF13 on surface cultures were evaluated. S. exfoliatus SMF13 produced leupeptin and chymotrypsin-like protease (CTP) at the stage of substrate mycelium growth, and leupeptin-inactivating enzyme (LIE) and trypsin-like protease (TLP) at the stage of aerial mycelium growth. The activity of leupeptin and CTP was high in the region of active growing substrate mycelium, whereas the activity of LIE and TLP was high in the region of aerial mycelium or spores. The differentiations were induced in glucose-limited conditions or by the addition of glucose anti-metabolite (methyl $\alpha$-glucopyranoside), but repressed by high concentrations of glucose or casamino acids. Morphological differentiation (formation of aerial mycelia and spores) was closely related with physiological differentiation (formation of brown-pigment, LIE and TLP). The local distribution of leupeptin, CTP, LIE, and TLP in a developing colony showed that colony development correlated with the production and functions of the compounds: CTP is essential for providing a nitrogen source for mycelium growth: leupeptin regulates TLP activity: LIE inactivates leupeptin: TLP hydrolyzes nongrowing mycelium.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.2
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• pp.280-287
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• 2000

Generally, buckwheat has been regarded as a crop of secondary importance in many countries. In vitro functionalities of buckwheats as a food were evaluated in this study. Five of buckwheat cultivars were extracted with methanol, and the extractant were dried and lyophilized, separately. Or water soluble buckwheat components were digested with the commercial enzymes and the obtained protein hydrolysate was again fractionated by acid precipitation. The antioxidant capacity of the methanol extracts determined using Fe2+-ascorbic acid system was dependent ont the cultivars: The extract of Suwon 4 showed 3.3 times stronger activity than ascorbic acid in terms of IC50. Also, the extracts of buckwheats inhibited efficiently the activities of $\alpha$-amylase and lens aldose reductase. Buckwheat soluble protein or rutin suppressed the in vitro activities of angiotensin-converting enzyme, and the inhibitory degree depended largely on the cultivars. Buckwheat proteins exerted higher hydrophobicity being related to the sterol binding capacity than casein. The results suggested that buckwheat seeds may be desirable and functional food resources in human living in current society.

• International Journal of Industrial Entomology and Biomaterials
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• v.22 no.2
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• pp.95-100
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• 2011

The effect of diet supplementation of Antheraea pernyi (A. pernyi) silk fibroin on the lipid metabolism and antioxidant defense status in high fat-fed mice was investigated. The animals were given normal control diet (NC group), high fat diet (HF group), or high fat diet supplemented with A. pernyi silk fibroin powder (HFS group) for 7 weeks. After the experimental period, the HF group showed significant increase in body weight, plasma and hepatic total cholesterol levels, and hepatic triglyceride concentration, and decreased activities of hepatic antioxidant enzymes relative to NC group. However, the HFS group exhibited marked reduction in body weight, plasma cholesterol and hepatic triglyceride levels, hepatic lipogenic enzyme activities, and lipid peroxidation rate, and higher high-density lipoprotein (HDL)-cholesterol level, fecal triglyceride content, and antioxidant enzymes activities compared with that of HF group. These findings demonstrate that dietary feeding of A. pernyi silk fibroin could improve the lipid metabolism and antioxidant defense system via regulation of hepatic antioxidant and lipogenic enzymes activities. Hence, this silk fibroin may be beneficial as a functional biomaterial for the development of therapeutic agent against high fat diet-induced hyperlipidemia and its related diseases.

• BMB Reports
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• v.42 no.9
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• pp.552-560
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• 2009

Cyclooxygenases (COX-1 and COX-2) are ER-resident proteins that catalyze the committed step in prostanoid synthesis. COX-1 is constitutively expressed in many mammalian cells, whereas COX-2 is usually expressed inducibly and transiently. Abnormal expression of COX-2 has been implicated in the pathogenesis of chronic inflammation and various cancers; therefore, it is subject to tight and complex regulation. Differences in regulation of the COX enzymes at the posttranscriptional and posttranslational levels also contribute significantly to their distinct patterns of expression. Rapid degradation of COX-2 mRNA has been attributed to AU-rich elements (AREs) at its 3’UTR. Recently, microRNAs that can selectively repress COX-2 protein synthesis have been identified. The mature forms of these COX proteins are very similar in structure except that COX-2 has a unique 19-amino acid (19-aa) segment located near the C-terminus. This C-terminal 19-aa cassette plays an important role in mediation of the entry of COX-2 into the ER-associated degradation (ERAD) system, which transports ER proteins to the cytoplasm for degradation by the 26S proteasome. A second pathway for COX-2 protein degradation is initiated after the enzyme undergoes suicide inactivation following cyclooxygenase catalysis. Here, we discuss these molecular determinants of COX-2 expression in detail.

• Journal of Animal Science and Technology
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• v.55 no.4
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• pp.303-314
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• 2013

Knowledge regarding lipid catabolism has been of great interest in the field of animal sciences. In the livestock industry, excess fat accretion in meat is costly to the producer and undesirable to the consumer. However, intramuscular fat (marbling) is desirable to enhance carcass and product quality. The manipulation of lipid content to meet the goals of animal production requires an understanding of the detailed mechanisms of lipid catabolism to help meticulously design nutritional, pharmacological, and physiological approaches to regulate fat accretion. The concept of a basic system of lipases and their co-regulators has been identified. The major lipases cleave triacylglycerol (TAG) stored in lipid droplets in a sequential manner. In adipose tissue, adipose triglyceride lipase (ATGL) performs the first and rate-limiting step of TAG breakdown through hydrolysis at the sn-1 position of TAG to release a non-esterified fatty acid (NEFA) and diacylglycerol (DAG). Subsequently, cleavage of DAG occurs via the rate-limiting enzyme hormone-sensitive lipase (HSL) for DAG catabolism, which is followed by monoglyceride lipase (MGL) for monoacylglycerol (MAG) hydrolysis. Recent identification of the co-activator (Comparative Gene Identification-58) and inhibitor [G(0)/G(1) Switch Gene 2] of ATGL have helped elucidate this important initial step of TAG breakdown, while also generating more questions. Additionally, the roles of these lipolysis-related enzymes in muscle, liver and skin tissue have also been found to be of great importance for the investigation of systemic lipolytic regulation.

• BMB Reports
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• v.50 no.11
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• pp.560-565
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• 2017

Geraniin, a hydrolysable tannin, used in traditional medicine in Southeast Asia, is known to exhibit various biological activities. As an antioxidant it is known to up-regulate phase II enzyme Heme oxygenase-1 (HO-1). However its mechanism is not clearly understood. Nuclear factor erythroid-derived 2 related factor 2 (Nrf-2) is transcriptionally up-regulated by Extracellular signal-regulated kinase (ERK) 1/2 and retained in nucleus due to inactivated Glycogen synthase kinase 3 beta ($GSK-3{\beta}$). Geraniin additionally down-regulates expression of microRNA 217 and 377 (miR-217 and miR-377) which target HO-1 mRNA. Expression of BTB and CNC homolog 1 (BACH-1), another regulator of HO-1, is also down-regulated by up-regulating microRNA 98 (miR-98), a negative regulator of BACH-1. Thus, geraniin up-regulates HO-1 expression both through activating its positive regulator Nrf-2 and by down-regulating its negative regulator BACH-1. Up-regulation of HO-1 also confers protection to HepG2 cells from tertiary butyl hydroperoxide (TBH) induced cytotoxicity.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.74.2-74
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• 2003

Arabidopsis infected with beet curly top virus (BCTV) has the systemic symptoms like stunting of Plant growth, curling of leaves and shoot tips, and callus induction. The regulation of sucrose metabolism by BCTV infection is essential for obtaining the energy source in the process of virus replication and symptom development. Sucrose metabolism-associated gene expression and biochemical enzyme activity were analyzed with the rossette leaves and inflorescencestems of BCTV infected Arabidopsis by the time course of 1, 7, 14, 21 day postinoculation. The expression of invertase and sucrose synthase genes ( encoding sucrose-cleaving enzymes )was increased and reversely the level of Atkin10a ( sucrose non-fermenting gene ) was decreased, resulting by semi-quantitative reverse transcription polymerase chain reaction. The biochemical analysis of invertase and sucrose synthase activity was performed. The activity of neutral invertase in the inflorescence stems was elevated remarkably. The photosynthetic response in the source of sucrose metabolism was consistent with the down-regulation of ribulose 1,5 bisphosphate carboxylase gene, and lower activity than mock-inoculated plants. The levels of genes pertaining to the cell cycle, hormone, and biotic stress-related pathway showed an increase or a decrease dependent on viral symptoms. Therefore, sucrose sensing by BCTV infection can regulate the expression of sucrose metabolism-related key enzymes such as invertase and Atkin10a, and these gene products might influence to symptom development.

• Reproductive and Developmental Biology
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• v.35 no.3
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• pp.215-219
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• 2011

Acyl-CoA synthetase 4(ACSL4) is an arachidonate-preferring enzyme abundant in steroidogenic tissues and postulated to modulate eicosanoid production. The human and mouse ACSL4 gene are mapped on chromosome X. The female mice heterozygous for ACSL4 deficiency became pregnant less frequent1y and produced small litters, with 40% of embryos surviving gestation. In this study, we examined the regulation of ACS4 by estradiol-$17{\beta}$ and progesterone (P4) in the human endometrial cancer cell line HTB-1B. ACSL4 mRNA was increased in a dose-dependent manner. Also, expression of ACSL4 gene was up-regulated in a time-dependent manner in HTB-1B cells. However, combined treatment with progesterone and estradiol-$17{\beta}$ modestly decreased the levels of ACS4L mRNA as compared with the estradiol-$17{\beta}$ and progesterone respectively. Overall, these results suggest that the ACSL4 gene is regulated by progesterone and estradiol-$17{\beta}$ in the HTB-1B cells.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.1
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• pp.55-62
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• 1998

${\alpha},\;{\beta}-Adrenergics$, and calcium channels were known to be related to inducing cardiac hypertrophy. Recently, it was reported that the cardiac renin-angiotensin system (RAS) was an important factor in ventricular hypertrophy. The present study was aimed to investigate the effects of ${\alpha},\;{\beta}-adrenergic$, and calcium channel blockers that might be involved in the regulation of cardiac RAS. The reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the expression of renin gene in the perfused rat heart. Changes in angiotensin converting enzyme (ACE) activity and cyclic AMP (cAMP) content which were thought to play a role in inducing cardiac hypertrophy were measured in the perfused rat heart. The expression of renin gene was not only increased by isoproterenol with metoprolol-pretreatment but also increased by vasopressin treatment in the presence of calcium channel blocker, nifedipine or verapamil. Either prazosin alone or norepinephrine with prazosin-pretreatment significantly increased the ACE activity. However, isoproterenol with metoprolol-pretreatment significantly decreased the ACE activity. On the other hand, the ACE activity was not changed by vasopressin, nifedipine, or verapamil treatments. The content of cAMP was significantly increased by either isoproterenol or vasopressin treatment. According to these results, renin gene expression was associated with ${\beta}2$ - adrenoceptor and calcium channel. ACE activity was associated with ${\alpha}-\;and{\beta}2$ - adrenoceptor. In conclusion, ${\beta}2$ - adrenoceptor was important in cardiac renin gene expression and ACE activity and ${\alpha},\;{\beta}$ -adrenergic, and calcium channel blockers might be involved in the regulation of cardiac RAS in a complicated way.

• Journal of Microbiology and Biotechnology
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• v.16 no.5
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• pp.795-798
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• 2006

The phosphoenolpyruvate-dependent carbohydrate phosphotransferase system (PTS) is responsible for the simultaneous transfer and phosphorylation of various carbon sources in Escherichia coli. The ptsG gene encoding the enzyme $IICB^{Glc}$, the membrane component of the glucose-specific PTS, is repressed by Mlc and activated by the CRP cAMP complex; various other factors, such as Fis, FruR, and ArcA, are also known to be involved in ptsG regulation. Thus, in an attempt to discover a novel gene affecting the regulation of ptsG, a mutant with a decreased ptsG transcription in the presence of glucose compared with the wild-type strain was screened using transposon random mutagenesis. The mutant was found to have a transposon insertion in yhjV, a putative gene encoding a transporter protein whose function is yet unknown.