• Journal of Microbiology and Biotechnology
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• v.16 no.6
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• pp.911-920
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• 2006

[ $CD8^+$ ] T Iymphocytes with the cytotoxic activity and capability to release various cytokines are the major players in immune responses against viral infection and cancer. To identify the proteins specific to resting or activated human CD8$^+$ T cells, human CD8$^+$ T cells were activated with anti-CD3+anti-CD28 mAb in the presence of IL-2. The solubilized proteins from resting and activated human CD8$^+$ T cells were separated by high-resolution two-dimensional polyacrylamide gel electrophoresis, and their proteomes were analyzed. Proteomic analysis of resting and activated T cells resulted in identification of 35 proteins with the altered expression. Mass spectrometry coupled with Profound and SWISS-PROT database analysis revealed that these identified proteins are to be functionally associated with cell proliferation, metabolic pathways, antigen presentation, and intracellular signal transduction pathways. We also identified six unknown proteins predicted from genomic DNA sequences specific to resting or activated CD8$^+$ T cells. Protein network studies and functional characterization of these novel proteins may provide new insight into the signaling transduction pathway of CD8$^+$ T cell activation.

• Journal of Plant Biotechnology
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• v.40 no.1
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• pp.1-8
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• 2013

Potato is the 4th important crop along with rice, wheat and maize. It contains high quality of starch with relatively high content of vitamin C and protein. However, there is a nutritionally limiting factor due to a low level of sulphur-containing essential amino acid including methionine and cysteine. Recently, recombinant DNA technology and metabolic engineering with genes involved in the bio-synthetic pathway have been applied to enhance the level of these essential amino acids. In this report, it has been discussed about the current status and bottleneck on the development of transgenic potato containing high level of sulphur-containing essential amino acids.

• Journal of Applied Biological Chemistry
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• v.62 no.1
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• pp.1-6
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• 2019

The flavonoid, isokaempferide, has various biological activities such as hepatoprotective, antimicrobial and antiproliferative effect and is extracted from Amburana cearensis and Cirsium rivulare (Jacq.). Biotransformation is an alternative tool for the synthesis of value-added flavonoids with inexpensive substrates. Here, to synthesize isokaempferide from naringenin, two genes, PFLS and Rice O-mthyltransferae-9 were introduced in Escherichia coli. Although isokaempferide was successfully synthesized, the amount of biosynthesis was no high. In order to increase the yields of isokaempferide, S-adenosylmethionine (SAM) used as a methyl donor was increased by deleting MetJ, which is a transcriptional regulator related to SAM biosynthetic pathway. Next we optimized the cell concentration and substrate feed concentration with the engineered E. coli strain. Through these strategies, the biosynthesis of isokaempferide was increased up to 87 mg/L.

• Journal of Plant Biotechnology
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• v.50
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• pp.70-75
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• 2023

In legumes, soyasaponins, one of triterpenoid saponins, are major components of secondary metabolites with a more diverse array of bioactive chemicals. Although the biosynthetic pathway of soyasaponins has been largely studied in soybean, the study on the soyasaponin contents and biosynthesis-related gene expression in pea (Pisum sativum L.) is poorly understood. Here, we found the accumulation of only soyasaponin Bb component in the sprouts of two Korean domestic pea cultivars (Dachung and Sachul). This pattern was consistent with our observation that increased expression of PsUGT73P2 and PsUGT91H4 genes, but not PsCYP72A69, could be responsible for biosynthesis of only soyasaponin Bb in pea by examining their gene expression. However, gradual accumulation of soyasaponin Bb at developmental stages was not consistent with the expression of PsUGT73P2 and PsUGT91H4, suggesting that the changes of their protein activities may affect the accumulation patterns of soyasaponin Bb. We also revealed that the increased expression levels of PsUGT73P2 and PsUGT91H4 during light to dark transition led to increase of soyasaponin Bb contents. Collectively, our results provided a molecular basis of metabolic engineering for enhancing useful soyasaponin Bb metabolites in Korean domestic pea cultivars.

• Reproductive and Developmental Biology
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• v.34 no.1
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• pp.47-53
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• 2010

Glycoprotein hormones have a common $\alpha$-subunit that is involved in the signaling pathway together with G protein, adenylcyclase and cAMP induction; however, it is an unclear how this common structure is related to hormonal action. To determine the biological functions of the COOH-terminal amino acids in the $\alpha$-subunit of these glycoprotein hormones, a tethered-molecule was constructed by fusing the $NH_2$-terminus of the $\alpha$-subunit to the COOH-terminus of the $\beta$-subunit of equine chorionic gonadotropin (eCG). The following deletion mutants were created by PCR; Ile was inserted at position 96 to form ${\Delta}96$, Lys was substituted at position 95 to form ${\Delta}95$, His was inserted at position 93 to form ${\Delta}93$ and Tyr was substituted at position 87 to form ${\Delta}87$. Each mutant was transfected into CHO-K1 cells. Tethered-wt eCG, and ${\Delta}96$, ${\Delta}95$, and ${\Delta}93$ mutants were efficiently secreted into the medium but the ${\Delta}87$ mutant was not secreted. Interestingly, the RT-PCR, real-time PCR, and northern blot analyses confirmed that the RNA was transcribed in the ${\Delta}87$ mutant. However, the ${\Delta}87$ mutant protein was not detected in the medium or the intracellular fraction of the cell lysates. The LH- and FSH-like activities of the recombinant proteins were assayed in terms of cAMP production using rat LH/CG and rat FSH receptors. The metabolic clearance rate (MCR) was determined by injecting rec-eCG (2 IU) into the tail vein. The ${\Delta}95$ and ${\Delta}93$ mutants were completely inactive in both the LH- and FSH-like activity assays. The ${\Delta}96$ mutant showed slight activity in the LH-like activity assay. In comparison to the wild type, the activity of the ${\Delta}96$ mutant in the FSH-like activity assay was the highest among all the mutants. The MCR assay in which rec-eCG was injected showed a peak at 10 min in all the treatment groups, which disappeared 4 h after injection. These results imply a direct interaction between the receptor and the COOH-terminal region of the a-subunit. The data also reveal a significant difference in the mechanism by which the eCG hormone interacts with the rLH and rFSH receptors. The COOH-terminal region of the $\alpha$-subunit is very important for the secretion and functioning of this hormone.

• Journal of Nutrition and Health
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• v.2 no.4
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• pp.173-181
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• 1969

Since 1959 ${\beta}-aminoethylphosphonic$ acid was discovered in the living organism, the biosynthesis and biological functions of aminophosphonic acids have been extensively studied. The author designed and carried out this study for 14 weeks to find out the metabolic function of Ethylaminophosphonic acid (AEP) and it's utilization in the living body. Sixty rats, thirty males and thirty females aged $40{\pm}5$ days were divided into two parts, one for alanine supplemented as control group and the other for AEP as experimental group to compare metabolic pathway of ordinary amino acid with that of AEP. Both alamine and AEP group were divived into two subgroups according to the level of supplements, 0.1% and 0.2% of the diet. The major components of the diet in this study were composed of 20% casein, 72% Sugar, 4% fat, 4% salt Mixture, and all kind of Uitamins in adeguate amount. For comparision of biological values between experimental and control group in terms of body weight, uninary nitrogen, creatinine excretion and final orgam weight, there were no statically significant difference in these respects. This meant AEP could be utilized in the body as much as alanine could. Urinary phosphorus excretion was determined by developing the blue color to read on the Spectronic 20. Statistically insignificance in the urinary phosphorus excretion between experimental and control group was observed in spite of the supplementation of phosphorus of AEP for experimental group in the diet. The level of blood phosphorus was higher in experimental group than that in control group this result supported above result. In the analysis of fat and nitrogen contents in the liver, AEP group showed slightly higher than control in both respects. But it was noteworthy 0.2% AEP group in both sex were higher than 0.1% AEP in liver fat content. Histological examinal of internal organs liiver, lung, spleen, heart, kindey, adrenal and sex organs showed no changes in all groups included in this study. The group supplemented higher level of diet. by alanine 0.2% and AEP 0.2% stayed on less body weight gain and lower liver weight. This result could be interpreted that amino acid imbalanced condition was arose in the body.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.5
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• pp.459-466
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• 2016

Adipogenic differentiation of mesenchymal stem cells (MSCs) is critical for metabolic homeostasis and nutrient signaling during development. However, limited information is available on the pivotal modulators of adipogenic differentiation of MSCs. Adaptor protein Lnk (Src homology 2B3 [SH2B3]), which belongs to a family of SH2-containing proteins, modulates the bioactivities of different stem cells, including hematopoietic stem cells and endothelial progenitor cells. In this study, we investigated whether an interaction between insulin-like growth factor-1 receptor (IGF-1R) and Lnk regulated IGF-1-induced adipogenic differentiation of MSCs. We found that wild-type MSCs showed greater adipogenic differentiation potential than $Lnk^{-/-}$ MSCs. An ex vivo adipogenic differentiation assay showed that $Lnk^{-/-}$ MSCs had decreased adipogenic differentiation potential compared with wild-type MSCs. Interestingly, we found that Lnk formed a complex with IGF-1R and that IGF-1 induced the dissociation of this complex. In addition, we observed that IGF-1-induced increase in the phosphorylation of Akt and mammalian target of rapamycin was triggered by the dissociation of the IGF-1R-Lnk complex. Expression levels of a pivotal transcription factor peroxisome proliferator-activated receptor gamma ($PPAR-{\gamma}$) and its adipogenic target genes (LPL and FABP4) significantly decreased in $Lnk^{-/-}$ MSCs. These results suggested that Lnk adaptor protein regulated the adipogenesis of MSCs through the $IGF-1/Akt/PPAR-{\gamma}$ pathway.

• Journal of Plant Biotechnology
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• v.40 no.4
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• pp.210-216
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• 2013

Efficient regeneration methods and transformation system are a priority for successful application of genetic engineering to vegetative propagated plants such as grape (Vitis labrusca L.). This research is to establish shoot regeneration system from plant explants for 'Campbell Early', 'Tamnara', 'Heukgoosul', 'Heukbosek' using two types of plant growth regulators supplemented to medium. The highest adventitious shoot regeneration rate of 5% was achieved on a medium containing of Murashige and Skoog (MS) inorganic salts and Linsmaier and Skoog (LS) vitamins, 2 mg/L of TDZ and 0.1 mg/L of IBA. Leaf tissue of 'Campbell Early', was co-cultivated with Agrobacterium strains, LBA4404 containing the vector pBI121 carrying with CaMV 35S promoter, gus gene as reporter gene and resistance to kanamycin as selective agent, the other Agrobacterium strains, GV3101 containing the vector pB7 WG2D carrying with mPAP1-D gene. mPAP1-D is a regulatory genes of the anthocyanin biosynthetic pathway. 'Campbell Early' harboring mPAP1-D gene was readily able to be selected by red color due to anthocyanin accumulation in the transformed shoot. These results might be helpful for further studies to enhance the transformation efficiency in grape.

• Journal of the Korean Applied Science and Technology
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• v.29 no.1
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• pp.71-80
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• 2012

Vinca alkaloids produced from Catharanthus roseus are one of the most important natural product drugs in treatments of human cancers. These anticancer drugs are derived from coupling of the two monomeric indole alkaloids, catharanthine and vindoline. In order to investigate vindoline biosynthesis, tabersonine-$CD_3$ 1a is synthesized to use as a deuterium labeled precursor, which is distinguished clearly from the natural counterpart. We show that these deuterium labeled tabersonine 1a are successfully incorporated into the vindoline biosynthetic pathway to yield three deuterated vindoline intermediates. 16-Hydroxytabersonine-$CD_3$ (m/z 356) 2a, 16-Methoxytabersonine-$CD_3$ (m/z 370) 3a, 16-Methoxy-2,3-dihydro-3-hydroxytabersonine-$CD_3$ (m/z 388) 4a are produced from the cell suspension culture measured by UPLC/MS at 5 and 13 days after feeding tabersonine. The conversion rates from 1a to 2a and 2a to 3a are fast, whereas that from 3a to 4a is much slower. This indicates that the rate determining step among the first three vindoline biosynthesis is the last step. As a result of the slow conversion rate from 3a to 4a, the accumulation level of 16-Methoxytabersonine-$CD_3$ 3a is significantly increased up to 13 days. The accumulation ratio among 2a, 3a and 4a is 1, 2 and 0.1 at 5 days. However, the peaks of desacetoxyvindoline-$CD_3$ 5a, deacetylvindoline-$CD_3$ 6a and vindoline-$CD_3$ 7a are not found from the cell extracts even after 13 days of incubation which may indicate no presence of their corresponding enzymes.