• 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.

• Fisheries and Aquatic Sciences
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• v.3 no.2
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• pp.135-142
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• 2000

In order to clarify the role of gonadal sex steroids in the synthesis of gonadotropin (GTH) subunits in immature rainbow trout, we examined in vitro and in vivo effects of testosterone (T) on the pituitary mRNA levels of GTH I $\beta$, GTH II$\beta$ and a subunits by Northern blot analysis and on the pituitary content levels of GTH I$\beta$ and GTH II$\beta$by radioimmunoassay (RIA). The mRNA levels of the a subunit in T-treated fish were not changed more dramatically than those in control fish both in vivo and in vitro. Interestingly, the mRNA levels of GTH I$\beta$ in T-treated fish were shown to be slightly lower than those in the control fish under these experimental conditions, but no differences were observed in pituitary GTH I$\beta$ contents. In contrast, the mRNA levels and pituitary contents of GTH II$\beta$ subunit were strongly increased by T both in vivo and in vitro. These results demonstrate that the expressions of GTH I$\beta$ and II$\beta$ subunit genes in immatue rainbow trout pituitary are subjected to differential regulation by T.

• Journal of Microbiology and Biotechnology
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• v.14 no.1
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• pp.197-201
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• 2004

A 2-D gel protein analysis of Lactobacillus reuteri ATCC 55739 produced spots corresponding to subunits of the pyruvate dehydrogenase complex, as identified by N-terminal protein sequencing. Oligonucleotide probes specific for the subunits of the pyruvate dehydrogenase complex were synthesized ,md used to screen a L. reuteri genomic library to clone the structural genes. Two positive clones were isolated and identified as having the same 2.2 kb insert. A pdhB encoding the $\beta$-subunit of El subunit (pyruvate dehydrogenase component) of the pyruvate dehydrogenase complex was located in the middle of the insert. Furthermore, a 5' truncated pdhA encoding the $\alpha$-subunit of the E1 subunit and a 3' truncated pdhC encoding the E2 subunit (dihydrolipoamide acetyltransferase) were also located upstream and downstream of the pdhB, respectively.

• Journal of Plant Biotechnology
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• v.4 no.2
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• pp.59-65
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• 2002

ADP-glucose pyrophosphorylase (AGPase) catalyzes the key regulatory step in starch biosynthesis. Two cDNA clones encoding AGPase subunits were isolated from the leaf cDNA library of Chinese cabbage (Brassica campestris L. spp. pekinensis). One was designated as BCAGPS for the small subunit and the other as BCAGPL for the large subunit. Both cDNAs have uninterrupted open reading frames deriving 57 kDa and 63 kDa polypeptides for BCAGPS and BCAGPL, respectively, which showed significant similarity to those of other dicot plants. Also, However, the deduced amino acid sequence of BCAGPL has a unique feature. That is, it contains two regions (Rl and R2) lacking in all other plant enzymes. This is the first report of BCAGPL containing Rl and R2 among plant large subunits as well as small subunits. From the genomic Southern analysis and BAC library screening, we inferred the genomic status of BCAGPS and BCAGPL gene.

• Korean Journal of Environmental Agriculture
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• v.27 no.4
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• pp.460-463
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• 2008

The change of glutelin contents in rice grain during the maturity period was investigated to determine optimum rice harvesting time. The glutelin content was increased with increasing time after heading. In this study, eight of glutelin subunits were found. Among the glutelin subunits, 7208-subunit (MW, 35 kD) contents was significantly increased at 65 days after heading compared with 55 and 60 days after heading. 7405-subunit (MW, 50 kD) contents was steadily increased with time after heading. The results showed that at 55th day after heading would be optimum time for harvest to get the low glutelin content of rice grain.

• Bulletin of the Korean Chemical Society
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• v.28 no.6
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• pp.1005-1009
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• 2007

Leukotriene B4 (LTB4) is a potent chemoattractant for leukocytes and considered to be an inflammatory mediator. Human BLT2 (hBLT2) is a low-affinity G-protein coupled receptor for LTB4 and mediates pertussis toxin-sensitive chemotactic cell movement. Here, we dissected the interaction between hBLT2 and G-protein alpha subunits using GST fusion proteins containing intracellular regions of hBLT2 and various Gα protein including Gα i1, Gα i2, Gα i3, Gα s1, Gα o1, and Gα z. Among the tested Gα subunits, Gα i3 showed the highest binding to the third intracellular loop region of hBLT2 with a dissociation constant (KD) of 5.0 × 10?6 M. These results suggest that Gα i3 has the highest affinity to hBLT2, and the third intracellular loop region of hBLT2 is the major component for the interaction with Gα i3.

• Genomics & Informatics
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• v.8 no.2
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• pp.63-69
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• 2010

Monofunctional biosynthetic peptidoglycan transglycosylase (MBPT) catalyzes the formation of the glycan chain in bacterial cell walls from peptidoglycan subunits: N-acetylglucosamine (NAG) and acetylmuramic acid (NAM). Bifunctional glycosyltransferases such as the penicillin binding protein (PBP) have peptidoglycan glycosyltransferase (PGT) on their C terminal end which links together the peptidoglycan subunits while transpeptidase (TP) on the N terminal end cross-links the peptide moieties on the NAM monosaccharide of the peptide subunits to create the bacterial cell wall. The singular function of MBPT resembles the C terminal end of PBP as it too contains and utilizes a similar PGT domain. In this article we analyzed the infectious and non infectious protein sequences of MBPT from 31 different strains of bacteria using a variety of bioinformatic tools. Motif analysis, dot-plot comparison, and phylogenetic analysis identified a number of significant differences between infectious and non-infectious protein sequences. In this paper we have made an attempt to explain, analyze and discuss these differences from an evolutionary perspective. The results of our sequence analysis may open the door for utilizing MBPT as a new target to fight a variety of infectious bacteria.

• Development and Reproduction
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• v.26 no.2
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• pp.37-47
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• 2022

Photoperiod has well been established to regulate testicular activities in golden hamsters. These animals breed actively around summer but become infertile in winter. In males, testicles are full of multistep germ cells including spermatozoa in summer. But in winter only fundamental cells consisting of the testicles are detected. The testicular degeneration is accompanied by the reduced levels of blood gonadotropins and testosterone. In this study, the expressions of gonadotropin subunit genes were investigated in the reproductive active and inactive testicles. And parts of sequences of the gonadotropin subunits were identified and compared with those of other rodents. As results, common gonadotropin alpha (CGa), follicle-stimulating hormone (FSH) β, and luteinizing hormone (LH) β genes were equivalently detected in pituitaries of both sexually active and inactive animals. In considering low concentrations of gonadotropin hormones determined in pituitary, the present findings imply that the processes involved in translation and/or formation of functional hormones could be impeded in the sexually inactive hamsters. All the nucleotide sequences of gonadotropin subunits identified in this study were same as those reported previously except for one base in CGa. An unsure amino acid deduced from the CGa sequence was confirmed from mRNA sequencing. The outcomes mentioned above suggest that animals with regressed testes prepare for the sexually active period forthcoming in the future.

• Journal of Microbiology and Biotechnology
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• v.27 no.8
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• pp.1461-1471
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• 2017

Escherichia coli heat-labile enterotoxin (LT) and its non-toxic mutant (LTm) are well-known powerful mucosal adjuvants and immunogens. However, the yields of these adjuvants from genetically engineered strains remain at extremely low levels, thereby hindering their extensive application in fundamental and clinical research. Therefore, efficient production of these adjuvant proteins from genetically engineered microbes is a huge challenge in the field of molecular biology. In order to explore the expression bottlenecks of LTm in E. coli, we constructed a series of recombinant plasmids based on various considerations and gene expression strategies. After comparing the protein expression among strains containing different recombinant plasmids, the signal sequence was found to be critical for the expression of LTm and its subunits. When the signal sequence was present, the strong hydrophobicity and instability of this amino acid sequence greatly restricted the generation of subunits. However, when the signal sequence was removed, abundantly expressed subunits formed inactive inclusion bodies that could not be assembled into the hexameric native form, although the inclusion body subunits could be refolded and the biological activity recovered in vitro. Therefore, the dilemma choice of signal sequence formed bottlenecks in the expression of LTm. These results reveal the expression bottlenecks of LTm, provide guidance for the preparation of LTm and its subunits, and certainly help to promote efficient preparation of this mucosal adjuvant protein.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.51-53
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• 2003