• Korean Journal of Poultry Science
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• v.50 no.4
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• pp.231-240
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• 2023

Infectious bursal disease (IBD) is an acute, highly contagious, and immunosuppressive disease in young chickens, and causes considerable economic losses to the poultry industry. More than 30 years ago, an antigenic variant IBDV (avIBDV) was reported in chicken farms in the United States. Recently, a novel avIBDV exhibited clear differences in molecular characteristics compared with previous variant strains. This study investigated the molecular characteristics of recently isolated avIBDV strains in Korea. Strains of avIBDV were confirmed by reverse transcription PCR (RT-PCR) and were propagated in 10-day-old specific-pathogen-free (SPF) embryonated chicken eggs through chorioallantoic membrane (CAM) inoculation. Multiple sequence alignment and phylogenetic analyses of hypervariable regions VP2 gene revealed that the strains originated from two different avIBDV lineages (G2a and G2d). In our results, we confirmed the co-existence and prevalence of avIBDV genogroup G2a and G2d in chicken farms. It is necessary to study the protective efficacy of current vaccines against avIBDVs.

• Molecules and Cells
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• v.26 no.5
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• pp.443-453
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• 2008

The Bric-a-brac, Tramtrack, Broad-complex (BTB) domain is a protein-protein interaction domain that is found in many zinc finger transcription factors. BTB containing proteins play important roles in a variety of cellular functions including regulation of transcription, regulation of the cytoskeleton, protein ubiquitination, angiogenesis, and apoptosis. Here, we report the cloning and characterization of a novel human gene, KLHL31, from a human embryonic heart cDNA library. The cDNA of KLHL31 is 5743 bp long, encoding a protein product of 634 amino acids containing a BTB domain. The protein is highly conserved across different species. Western blot analysis indicates that the KLHL31 protein is abundantly expressed in both embryonic skeletal and heart tissue. In COS-7 cells, KLHL31 proteins are localized to both the nucleus and the cytoplasm. In primary cultures of nascent mouse cardiomyocytes, the majority of endogenous KLHL31 proteins are localized to the cytoplasm. KLHL31 acts as a transcription repressor when fused to GAL4 DNA-binding domain and deletion analysis indicates that the BTB domain is the main region responsible for this repression. Overexpression of KLHL31 in COS-7 cells inhibits the transcriptional activities of both the TPA-response element (TRE) and serum response element (SRE). KLHL31 also significantly reduces JNK activation leading to decreased phosphorylation and protein levels of the JNK target c-Jun in both COS-7 and Hela cells. These results suggest that KLHL31 protein may act as a new transcriptional repressor in MAPK/JNK signaling pathway to regulate cellular functions.

• Journal of Life Science
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• v.26 no.4
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• pp.460-467
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• 2016

A filamentous cyanobacterium, Limnothrix sp. KNUA012, was axenically isolated from a freshwater bloom sample in Lake Hapcheon, Hapcheon-gun, Gyeongsangnam-do, Korea. Its morphological and molecular characteristics led to identification of the isolate as a member of the genus Limnothrix. Maximal growth was attained when the culture was incubated at 25℃. Analysis of its lipid composition revealed that strain KNUA012 could autotrophically synthesize alkanes, such as pentadecane (C₁₅H₃₂) and heptadecane (C₁₇H₃₆), which can be directly used as fuel without requiring a transesterification step. Two genes involved in alkane biosynthesis－an acyl-acyl carrier protein reductase and an aldehyde decarbonylase－were present in this cyanobacterium. Some common algal biodiesel constituents－myristoleic acid (C_14:1), palmitic acid (C_16:0), and palmitoleic acid (C_16:1)－were produced by strain KNUA012 as its major fatty acids. A proximate analysis showed that the volatile matter content was 86.0% and an ultimate analysis indicated that the higher heating value was 19.8 MJ kg⁻¹. The isolate also autotrophically produced 21.4 mg g⁻¹ phycocyanin－a high-value antioxidant compound. Therefore, Limnothrix sp. KNUA012 appears to show promise for application in cost-effective production of microalga-based biofuels and biomass feedstock over crop plants.

• Microbiology and Biotechnology Letters
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• v.44 no.2
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• pp.130-139
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• 2016

A bacterial strain, producing an excellent lipolytic enzyme, was isolated from the intestinal tracts of an earthworm (Eisenia fetida). The strain was identified as Aeromonas hydrophila by phenotypic, chemotaxonomic characteristics and 16S ribosomal DNA analysis, and was designated as Aeromona hydrophila PL43. The lipolytic enzyme from A. hydrophila PL43 was purified via 35−45% ammonium sulfate precipitation, DEAE-sepharose fast flow ion-exchange, and sephacryl S-300HR gel filtration chromatography. The yield of the purified enzyme was 3.7% and 2.5% of the total activity of crude extracts with p-nitrophenyl butyrate (pNPB) and p-nitrophenyl palmitate (pNPP) as substrates, respectively. The molecular weight of the purified enzyme was approximately 74 kDa using gel filtration, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and zymography. The optimal activity of purified enzyme was observed at 50℃ and pH 8.0 using pNPB, and 60℃ and pH 8.0 using pNPP. The purified enzyme was stable in the ranges 20− 60℃ and pH 7.0−10.0. The activity of purified enzyme was inhibited by PMSF, pepstatin A, Co²⁺, Cu²⁺, and Fe²⁺, but was recovered by metal chelating of EDTA. The K_m and V_max values of the purified enzyme were 1.07 mM and 7.27 mM/min using pNPB and 1.43 mM and 2.72 mM/min using pNPP, respectively.

• Clinical and Experimental Pediatrics
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• v.46 no.2
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• pp.128-136
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• 2003

Purpose : Hyper IgM syndrome(HIGM) is characterized by severe recurrent bacterial infections with decreased serum levels of IgG, IgA, and IgE but elevated IgM levels. Recently, it has been classified into three groups; HIGM1, HIGM2 and a rare form of HIGM. HIGM1 is a X-linked form of HIGM and has now been identified as a T-cell deficiency in which mutations occur in the gene that encodes the CD40 ligand molecule. HIGM2 is an autosomal recessive form of HIGM. Molecular studies have shown that the mutation of HIGM2 is in the gene that encodes activation-induced cytidine deaminase(AID). Recently, another rare form of X-linked HIGM syndrome associated with hypohydrotic ectodermal dysplasia has been identified. We encountered a patient with a varient form of HIGM2. To clarify the cause of this form of HIGM, we evaluated the peripheral B cells of this patient. Methods : The lymphocytes of the patient were prepared from peripheral blood. B cells were immortalized with the infection of EBV. Cell cycle analysis was done with the immortalized B cells of the patient. Peripheral mononuclear cells were stained with monoclonal anti-CD40L antibody. Total RNA was extracted from the peripheral mononuclear cells. After RT-PCR, direct sequencing for CD40L gene and HuAID gene were done. Immunostainings of a lymph node for CD3, CD23, CD40, Fas-L, bcl-2, BAX were done. Results : The peripheral B cells of this patient showed normal expression of CD40L molecule and normal sequencing of CD40L gene, and also normal sequencing of AID gene. Interestingly, the peripheral B cells of this patient showed a decreased population of G2/mitosis phase in cell cycles which recovered to normal with the stimulation of IL-4. Conclusion : We suspect that the cause of increased serum IgM in this patient may be from a decrease of G2/mitosis phase of the peripheral B cells, which may be from the decreased production or secretion of IL-4. Therefore, this may be a new form of HIGM.

• The korean journal of orthodontics
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• v.33 no.6 s.101
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• pp.485-497
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• 2003

The form and function of the craniofacial structure critically depend on genetic information. With recent advances in the molecular technology, genes that are important for normal growth and morphogenesis of the craniofacial skeleton are being rapidly uncovered, shaping up modem craniofacial biology. One of them is fibroblast growth factor receptor 2 (FGFR2). Specific point mutations in the. FGFR2 gene have been linked to Apert syndrome, which is characterized by premature closure of cranial sutures and craniofacial anomalies as well as limb deformities. To study pathogenic mechanisms underlying craniosynostosis phenotype of Apert syndrome, we used a transgenic approach; an FGFR2 minigene construct containing an Apert mutation (a point mutation that substitute proline at the position 253 to arginine; P253R) was introduced into fertilized mouse germ cells by DNA microinjection. The injected cells were then allowed to develop into transgenic mice. We used a bone-specific promoter (a DNA fragment from the type I collagen gene) to confine the expression of mutant FGFR2 gene to the bone tissue, and asked whether expression of mutant FGFR2 in bone is sufficient to cause the craniosynostosis phenotype in mice. Initial characterization of these mice shows prematurely closed cranial sutures with facial deformities expected from Apert patients. We also demonstrate that the transgene produces mutant FGFR2 protein with increased functional activities. Having this useful mouse model, we now can ask questions regarding the role of FGFR2 in normal and abnormal development of cranial bones and sutures.

• Microbiology and Biotechnology Letters
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• v.37 no.2
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• pp.99-104
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• 2009

The $\beta$-glucosidase gene from Streptomyces coelicolor A3(2) was cloned and expressed in Escherichia coli. The ORF consisted of 1377 nucleotides encoding 51 kDa in a predicted molecular weight. Effects of pH indicated that the $\beta$-glucosidase showed similar activity using $\alpha$-pNPG($\rho$-nitrophenyl-$\alpha$-D-glucopyranoside), $\beta$-pNPG($\rho$-nitrophenyl-$\beta$-D-glucopyranoside), and $\beta$-pNPF($\rho$-nitrophenyl-$\beta$-D-fucopyranoside) at range of pH 3 to 10, and high activity using $\beta$-pNPGA ($\rho$-nitrophenyl-$\beta$-D-galactopyranoside) from pH 5 to 10, especially, 3.3 times higher activity at pH 9. Effects of temperature indicated that the $\beta$-glucosidase showed low activity using $\alpha$-pNPG, $\beta$-pNPG, and $\beta$-pNPF from $20^{\circ}C$ to $70^{\circ}C$, and increased activity using $\beta$-pNPGA from $30^{\circ}C$ to $50^{\circ}C$, 1.8 times higher activity at $50^{\circ}C$ than at $30^{\circ}C$. According to activity determination of other substrates, the enzyme was active on daidzin, genistin, and glycitin, inactive on esculin and apigenin-7-glucose. The EDTA and DTT as reducing agents inhibited $\beta$-glucosidase activity, but SDS and mercaptoethanol did not inhibit. Monovalent or divalent metal ions such as $MnSO_4$, $CaCl_2$, KCl, and $MgSO_4$ did not inhibited $\beta$-glucosidase activity. $CuSO_4$ and NaCl showed low inhibition, and $ZnSO_4$ inhibited 3.3 times higher than control.

• Journal of Plant Biotechnology
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• v.35 no.3
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• pp.169-176
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• 2008

Salicylic acid(SA) is a phytohormone that is related to plant defense mechanism. The SA accumulation is triggered by abiotic and biotic stresses. SA acts as a signal molecular compound mediating systemic acquired resistance and hypersensitive response in plant. Although the role of SA has been studied extensively, an understanding of the SA regulatory mechanism is still lacking in plants. In order to comprehend SA regulatory mechanism, we have been transformed with a SID2 promoter:GUS::LUC fusion construct into siz1-2 mutant and wild plant(Col-0). SIZ1 encodes SUMO E3 ligase and negatively regulates SA accumulation in plants. SID2(SALICYLIC ACID INDUCTION DEFICIENT2) is a crucial enzyme of SA biosynthesis. The Arabidopsis SID2 gene encodes isochorismate synthase(ICS) that controls SA level by conversion of chorismate to isochorismate. We compared the regulation of SID2 in wild-type and siz1-2 transgenic plants that express SID2 promoter:GUS::LUC constructs respectively. The expressions of $\beta$-GLUCURONIDASE and LUCIFERASE were higher in siz 1-2 transgenic plant without any stress treatment. SID2 promoter:GUS::LUC/siz1-2 transgenic plant will be used as a starting material for isolation of siz1-2 suppressor mutants and genes involved in SA-mediated stress signaling pathway.

• Journal of Plant Biotechnology
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• v.35 no.3
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• pp.177-183
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• 2008

Ac/Ds mutant lines of this study were transgenic rice plants, each of which harbored the maize transposable element Ds together with a GUS coding sequence under the control of a promoterless(Ds-GUS). We selected the mutants that were GUS expressed lines, because the GUS positive lines will be useful for identifying gene function in rice. One of these mutants was identified knock-out at Oszinc626(NP_001049991) gene, encoding a RING-H2 zinc-finger protein, by Ds insertion. In this mutant, while primary root development is normal, secondary root development from lateral root was very poor and seed development was incomplete compare with normal plant. RING zinc-finger proteins play important roles in the regulation of development in a variety of organisms. In the plant kingdom, a few genes encoding RING zinc-finger proteins have been documented with visible effects on plant growth and development. The consensus of the RING-H2(C3-H2-C3 type) domain for this group of protein is $Cys-X_2-Cys-X_{28}-Cys-X-His-X_2-His-X_2-Cys-X_{14}-Cys-X_2-Cys$. Oszinc626 encodes a predicted protein product of 445 amino acids residues with a molecular mass of 49 kDa, with a RING-zinc-finger motif located at the extreme end of the C-terminus. RT-PCR analysis indicated that the expression of Oszinc626 gene was induced by IAA, cold, dehydration, high-salinity and abscisic acid, but not by 2,4-D, and the transcription of Oszinc626 gene accumulated primarily in rice immature seeds, root meristem and shoots. The gene accumulation patterns were corresponded with GUS expression.

• Journal of Life Science
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• v.18 no.2
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• pp.264-272
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• 2008

The lactate dehydrogenase (EC 1.1.1.27, LDH) isozymes in tissues from Acanthogobius hasta were characterized by biochemical, immunochemical and kinetic methods. The activities of LDH in skeletal muscle and eye tissues were 65.30 and 53.25 units, but LDH activities in heart and liver tissues were very low. LDH/CS (EC 4.1.3.7, citrate synthase) in skeletal muscle was the highest as 22.29. Specific activities of LDH in brain, eye and skeletal muscle were 56.45, 38.04 and 11.0 units/mg, respectively. The LDH isozymes in tissues were separated by polyacrylamide gel electrophoresis after immunoprecipitation with antiserum against $A_4,\;B_4$ eye-specific $C_4$ and liver-specific $C_4$. LDH $AC_4$ isozymes were detected predominantly in skeletal muscle, brain and eye tissues, and $B_4$ isozyme was detected in heart. Anodal eye-specific $C_4$ and cathodal liver-specific $C_4$ were coexpressed in A. hasta. The eye-specific $C_4$ isozyme showed higher activity in eye tissue, but liver-specific $C_4$ isozyme showed lower activity in liver. As a result, one part of molecular structures in $A_4\;and\;C_4,\;A_4\;and\;B_4$, and eye-specific $C_4$ and liver-specific $C_4$ were similar, but in $B_4\;and\;C_4$ were different with each other. Therefore the subunit A may be conservative in evolution, and the evolution of subunit B seems to be faster than that of subunit A. The LDH $A_4$ isozyme of skeletal muscle was purified in the fraction from elution with NAD+ containing buffer of affinity chromatography and eye-specific $C_4$ isozyme was eluted right after $A_4$, so the structure of eye-specific $C_4$ isozyme is similar to $A_4$. And LDH activity remained 35.22-43.47% as a result of the inhibition by pyruvate, the Michaelis-Menten constant values for pyruvate was 0.080-0.098 mM, and Vmax were 153.85 units, 35.09 units in skeletal muscle and eye, respectively. Also the $B_4$ isozyme was the thermo-stablest and $C_4$ was stabler than $A_4$ isozyme. The optimum pH of LDH was 6.5. The results mentioned above indicate that isozymes in tissues showed the properties between LDH $A_4\;and\;B_4$ isozyme as A. hasta was adapted to hypoxic conditions. Also LDH seems to function more effectively under anaerobic condition because LDH in skeletal muscle and eye tissues have high affinity for pyruvate.