• Biomolecules & Therapeutics
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• v.27 no.6
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• pp.577-583
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• 2019

Human cytochrome P450 2C9 is a highly polymorphic enzyme that is required for drug and xenobiotic metabolism. Here, we studied eleven P450 2C9 genetic variants-including three novel variants F69S, L310V, and Q324X-that were clinically identified in Korean patients. P450 2C9 variant enzymes were expressed in Escherichia coli and their bicistronic membrane fractions were prepared The CO-binding spectra were obtained for nine enzyme variants, indicating P450 holoenzymes, but not for the M02 (L90P) variant. The M11 (Q324X) variant could not be expressed due to an early nonsense mutation. LC-MS/MS analysis was performed to measure the catalytic activities of the P450 2C9 variants, using diclofenac as a substrate. Steady-state kinetic analysis revealed that the catalytic efficiency of all nine P450 2C9 variants was lower than that of the wild type P450 2C9 enzyme. The M05 (R150L) and M06 (P279T) variants showed high $k_{cat}$ values; however, their $K_m$ values were also high. As the M01 (F69S), M03 (R124Q), M04 (R125H), M08 (I359L), M09 (I359T), and M10 (A477T) variants exhibited higher $K_m$ and lower $k_{cat}$ values than that of the wild type enzyme, their catalytic efficiency decreased by approximately 50-fold compared to the wild type enzyme. Furthermore, the novel variant M07 (L310V) showed lower $k_{cat}$ and $K_m$ values than the wild type enzyme, which resulted in its decreased (80%) catalytic efficiency. The X-ray crystal structure of P450 2C9 revealed the presence of mutations in the residues surrounding the substrate-binding cavity. Functional characterization of these genetic variants can help understand the pharmacogenetic outcomes.

• Molecules and Cells
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• v.45 no.7
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• pp.454-464
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• 2022

DJ-1 is one of the causative genes of early-onset familial Parkinson's disease (PD). As a result, DJ-1 influences the pathogenesis of sporadic PD. DJ-1 has various physiological functions that converge to control the levels of intracellular reactive oxygen species (ROS). Based on genetic analyses that sought to investigate novel antioxidant DJ-1 downstream genes, pyruvate dehydrogenase (PDH) kinase (PDK) was demonstrated to increase survival rates and decrease dopaminergic (DA) neuron loss in DJ-1 mutant flies under oxidative stress. PDK phosphorylates and inhibits the PDH complex (PDC), subsequently downregulating glucose metabolism in the mitochondria, which is a major source of intracellular ROS. A loss-of-function mutation in PDK was not found to have a significant effect on fly development and reproduction, but severely ameliorated oxidative stress resistance. Thus, PDK plays a critical role in the protection against oxidative stress. Loss of PDH phosphatase (PDP), which dephosphorylates and activates PDH, was also shown to protect DJ-1 mutants from oxidative stress, ultimately supporting our findings. Further genetic analyses suggested that DJ-1 controls PDK expression through hypoxia-inducible factor 1 (HIF-1), a transcriptional regulator of the adaptive response to hypoxia and oxidative stress. Furthermore, CPI-613, an inhibitor of PDH, protected DJ-1 null flies from oxidative stress, suggesting that the genetic and pharmacological inhibition of PDH may be a novel treatment strategy for PD associated with DJ-1 dysfunction.

• Journal of Animal Science and Technology
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• v.47 no.1
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• pp.1-10
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• 2005

Intramuscular fat content(lMF) is considered as one of major economic traits in the pig breeding and industry. In general, high IMF results in better meat quality. Several approaches to detect quantitative trait 10ci( QTL) for IMF indicated a strong possibility of the existence of a QTL related to IMF between the microsatellite marker SW71 and SW1881 on SSC6q. Porcine FABP3 has been considered as a candidate gene affecting IMF due to its physiological roles and position on the pig genome. Two novel mutations, g.-114T> C and g.-158T>G were detected by duplicate sequencing of the porcine FABP3 promoter region. These two mutations were identified as absolute linkage disequilibrium. The g.-158T> G mutation was used for investigating relationships with growth and fat deposition traits. The GG genotype of the g.-158T> G polymorphism showed highly negative effects(P< 0.01) on body weights at 3 and 12 weeks of age, and a positive effect(P< 0.05) on IMF. However, backfat thickness(BF) and carcass fat(CF) content were not significantly associated with the genotype. The result indicates that the novel mutations, identified in this study, could be utilized as possible genetic markers to improve IMF, independent with BF.

• Molecules and Cells
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• v.24 no.3
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• pp.409-415
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• 2007

The retinoblastoma (Rb) gene is one of the most important genes in cell cycle regulation and tumorigenesis. Homozygosity for a germ-line Rb mutation results in embryonic lethality and evokes developmental defects associated with inappropriate S-phase entry and high levels of apoptosis. Although Rb has been extensively studied, more target genes need to be identified and characterized to unravel the precise mechanism of Rb function. In order to identify Rb-regulated genes, we analyzed the gene expression profile of Rb-deficient mouse embryo fibroblasts (MEFs), and identified an unknown gene, RbEST47, that is transcriptionally upregulated in Rb-deficient MEFs. This gene is conserved from fruitfly to human. It is expressed in brain, lung, kidney, and testis, and is located on mouse chromosome 2. This region is syntenic to human chromosome 9q34.3, which frequently exhibits loss of heterozygosity in neoplastic diseases. RbEST47 was considerably down-regulated in immortalized cells, and showed cell cycle-dependent expression, suggesting important roles in S and/or G2.

• Clinical and Experimental Pediatrics
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• v.60 no.12
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• pp.408-412
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• 2017

Combined oxidative phosphorylation deficiency-17 (COXPD-17) is very rare and is caused by homozygous or compound heterozygous mutations in the ELAC2 gene on chromosome 17p12. The ELAC2 gene functions as a mitochondrial tRNA processing gene, and only 4 different pathogenic mutations have been reported in ELAC2-associated mitochondrial dysfunction involving oxidative phosphorylation. Affected patients show various clinical symptoms and prognosis, depending on the genotype. We report a novel mutation in the ELAC2 gene (c.95C>G [p.Pro32Arg], het), in an infant with COXPD-17 who presented with encephalopathy including central apnea and intractable epilepsy, and growth and developmental retardation. During hospitalization, consistently elevated serum lactic acid levels were noted, indicative of mitochondrial dysfunction. The patient suddenly died of shock of unknown cause at 5 months of age. This is the first case report of COXPD-17 in Korea and was diagnosed based on clinical characteristics and genetic analysis.

• Neonatal Medicine
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• v.25 no.3
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• pp.126-130
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• 2018

Parkes Weber syndrome is a rare congenital vascular anomaly, related to the RAS p21 protein activator 1 (RASA1) gene. It is characterized by capillary cutaneous malformations, bony and soft tissue hyperplasia, and multiple arteriovenous fistulas throughout the affected upper or lower extremity. These arteriovenous fistulas can be associated with life-threatening complications such as bleeding, thrombosis, and high output heart failure. In this report, we present a neonate who had a disproportionately hypertrophied left upper limb with port-wine stain, dystrophy of the left humerus, and hypertrophy of the left clavicle on X-ray, and arteriovenous malformation and massive dilatation of the left subclavian artery on magnetic resonance angiography. Exome sequencing analysis revealed a novel heterozygous splicing mutation (c.1776+2T>A) in the RASA1 gene. To the best of our knowledge, this report is the first case of RASA1-related Parkes Weber syndrome in Korea.

• Journal of Korean Neurosurgical Society
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• v.61 no.3
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• pp.333-342
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• 2018

Intracranial germ cell tumors (iGCTs) are a heterogeneous group of tumors with peculiar characteristics clearly distinguished from other brain tumors of neuroepithelial origin. Diverse histology, similarity to gonadal GCT, predilection to one sex, and geographic difference in incidence all present enigmas and fascinating challenges. The treatment of iGCT has advanced for germinoma to date; thus, clinical attention has shifted from survival to long-term quality of life. However, for non-germinomatous GCT, current protocols provide only modest improvement and more innovative therapies are needed. Recently, next-generation sequencing studies have revealed the genomic landscape of iGCT. Novel mutations in the KIT-RAS-MAPK and AKT-MTOR pathways were identified. More importantly, methylation profiling revealed a new method to assess the pathogenesis of iGCT. Molecular research will unleash new knowledge on the origin of iGCT and solve the many mysteries that have lingered on this peculiar neoplasm for a long time.

• BMB Reports
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• v.44 no.9
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• pp.584-589
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• 2011

The mammalian ste20-like kinase (MST) pathway is important in the regulation of apoptosis and cell cycle and emerges as a novel tumor suppressor pathway. MST-induced phosphorylation of Salvador homolog 1 (SAV1), which is a scaffold protein, has not been evaluated in detail. We performed a mass spectrometric analysis of the SAV1 protein that was co-expressed with MST2. Phosphorylation was detected at Thr-26, Ser-27, Ser-36 and Ser-269. Although single or double mutations had little effects, the mutation of all four residues in SAV1 to Ala (SAV1-4A) had inhibitory effects on the MST pathway. MST2-mediated induction of SAV1-4A protein levels, SAV1-4A interaction with MST2 and the self-dimerization of SAV1-4A were weaker compared to those of wild-type SAV1. SAV1-4A inhibited MST2- and K-RasG12V-induced cell death of MCF7 cells. These results suggest that MST-mediated phosphorylation of four residues within SAV1 may be important in the induction of cell death by the MST pathway.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.11
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• pp.5489-5511
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• 2019

The performance of evolutionary algorithms can be seriously weakened when constraints limit the feasible region of the search space. In this paper we present a constrained multi-objective optimization algorithm based on adaptive ε-truncation (ε-T-CMOA) to further improve distribution and convergence of the obtained solutions. First of all, as a novel constraint handling technique, ε-truncation technique keeps an effective balance between feasible solutions and infeasible solutions by permitting some excellent infeasible solutions with good objective value and low constraint violation to take part in the evolution, so diversity is improved, and convergence is also coordinated. Next, an exponential variation is introduced after differential mutation and crossover to boost the local exploitation ability. At last, the improved crowding density method only selects some Pareto solutions and near solutions to join in calculation, thus it can evaluate the distribution more accurately. The comparative results with other state-of-the-art algorithms show that ε-T-CMOA is more diverse than the other algorithms and it gains better in terms of convergence in some extent.

• Journal of Microbiology and Biotechnology
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• v.10 no.2
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• pp.161-168
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• 2000

Plasmid pLEX3 isolated from the recombinant cosmid library of Zoogloea ramigera 115 was found to be responsible for the restoration of the rugose colony phenotype. To confirm the essential region responsible for the complementation, subclones were constructed from plasmid pLEX3 and transformed into mutant strain Z. ramigera 115SLR. The recombinant plasmids pLEX10 and pLEX11 were shown to complement the slime-forming property of Z. ramigera 115SLR. In a compositional analysis of the exopolysaccharides from Z. ramigera 115, Z. ramigera 115SLR, and Z. ramigera 115SLR harboring plasmid pLEX11, the exopolysaccharides showed a similar composition with glucose, galactose, and side chain groups. The complete nucleotide sequence of the 3.25kb genocim DNA insert in plasmid pLEX11 was determined and its analysis identified two open reading frames which could encode two proteins. The gene products derived form the two open reading frames were confirmed by and in vivo transcription using a T7-RNA polymerase. The ORF1 produced a 30 kDa protein, whereas the ORF2 was found responsible for the complementation of the morphological mutation and produced a 14 kDa protein. An in vivo gene expression of plasmid pTEX10 showed another open reading frame encoding a 50 kDa protein. The gene products form ORF1 and ORF2 are regarded as novel proteins which do not show any homology with other proteins.