• BMB Reports
• /
• v.40 no.5
• /
• pp.611-616
• /
• 2007

$E^{rns}$ is an envelope glycoprotein of classical swine fever virus (CSFV) and has an unusual feature of RNase activity. In the present study, we demonstrate that $E^{rns}$ counteracts Newcastle disease virus (NDV)-mediated induction of IFN-$\beta$. For this purpose, $E^{rns}$ fused to the enhanced green fluorescent protein (EGFP) was transiently expressed in porcine kidney 15 (PK15) cells. In luciferase activity assay, $E^{rns}$-EGFP was found to prevent IFN-$\beta$ promoter-driven luciferase expression and block the induction of IFN-$\beta$ promoter mediated by NDV in a dose-dependent manner. Through IFN-specific semi-quantitative RT-PCR detection, obvious decrease of IFN-$\beta$ mRNA in NDV-infected PK15 cells was observed in the presence of $E^{rns}$-EGFP. In contrast, EGFP alone showed none of this block capacity. In addition, $E^{rns}$-EGFP mutations with RNase inactivation were also found to block NDV-mediated induction of IFN-$\beta$. These evidences establish a novel function for CSFV $E^{rns}$ glycoprotein in counteraction of the IFN-$\beta$ induction pathway.

• Journal of Microbiology and Biotechnology
• /
• v.18 no.4
• /
• pp.631-638
• /
• 2008

Tandem affinity purification (TAP) method combined with LC-MS/MS is the most accurate and reliable way to study the interaction of proteins or proteomics in a genome-wide scale. For the first time, we used a TAP-tag as a mutagenic tool to disrupt protein interactions at the specific site. Although lots of commonly used mutational tools exist to study functions of a gene, such as deletional mutations and site-directed mutagenesis, each method has its own demerit. To test the usefulness of a TAP-tag as a mutagenic tool, we applied a TAP-tag to RNA polymerase II, which is the key enzyme of gene expression and is controlled by hundreds of transcription factors even to transcribe a gene. Our experiment is based on the hypothesis that there will be interrupted interactions between Pol II and transcription factors owing to the TAP-tag attached at the C-terminus of each subunit of Pol II, and the abnormality caused by interrupted protein interactions can be observed by measuring a cell-cycle of each yeast strain. From ten different TAP-tagged strains, Rpb7- and Rpb12-TAP-tagged strains show severe defects in growth rate and morphology. Without a heterodimer of Rpb4/Rpb7, only the ten subunits Pol II can conduct transcription normally, and there is no previously known function of Rpb7. The observed defect of the Rpb7-TAP-tagged strain shows that Rpb7 forms a complex with other proteins or compounds and the interruption of the interaction can interfere with the normal cell cycle and morphology of the cell and nucleus. This is a novel attempt to use a TAP-tag as a proteomic tool to study protein interactions.

• Clinical and Experimental Pediatrics
• /
• v.57 no.5
• /
• pp.240-244
• /
• 2014

Pseudohypoparathyroidism type Ia (PHP Ia) is a disorder characterized by multiform hormonal resistance including parathyroid hormone (PTH) resistance and Albright hereditary osteodystrophy (AHO). It is caused by heterozygous inactivating mutations within the Gs alpha-encoding GNAS exons. A 9-year-old boy presented with clinical and laboratory abnormalities including hypocalcemia, hyperphosphatemia, PTH resistance, multihormone resistance and AHO (round face, short stature, obesity, brachydactyly and osteoma cutis) which were typical of PHP Ia. He had a history of repeated convulsive episodes that started from the age of 2 months. A cranial computed tomography scan showed bilateral calcifications in the basal ganglia and his intelligence quotient testing indicated mild mental retardation. Family history revealed that the patient's maternal relatives, including his grandmother and 2 of his mother's siblings, had features suggestive of AHO. Sequencing of the GNAS gene of the patient identified a heterozygous nonsense mutation within exon 11 (c.637 C>T). The C>T transversion results in an amino acid substitution from Gln to stop codon at codon 213 ($p.Gln213^*$). To our knowledge, this is a novel mutation in GNAS.

• Microbiology and Biotechnology Letters
• /
• v.47 no.4
• /
• pp.645-650
• /
• 2019

Despite differences in virulence between strains of Toxoplasma gondii, rapid and accurate genotyping methods are lacking. In this study, a method was developed to detect and genotype T. gondii in food and environmental samples using PCR and a novel peptide nucleic acid (PNA) melting array. An alignment of genome sequences for T. gondii type I, II, and III obtained from NCBI was generated, and a single nucleotide polymorphism analysis was performed to identify targets for PCR amplification and a PNA melting array. Prior to the PNA melting array, conventional PCR was used to amplify GRA6 of T. gondii. After amplification, the PNA melting array was performed using two different PNA hybridization probes with fluorescent labels (FAM and HEX) and quenchers. Melting curves for each probe were used to determine genotypes and identify mutations. A 214-bp region of the GRA6 gene of T. gondii was successfully amplified by PCR. For all T. gondii strains (type I, II, and III) used to evaluate specificity, the correct genotypes were determined by the PNA melting array. Non-T. gondii strains, including 14 foodborne pathogens and 3 protozoan parasites, such as Giardia lamblia, Cryptosporidium parvum, and Entamoeba histolytica, showed no signal, suggesting that the assay has a high specificity. Although this is only a proof-of-concept study, the assay is promising for the fast and reliable genotyping of T. gondii from food and environmental samples.

• Clinical and Experimental Pediatrics
• /
• v.48 no.5
• /
• pp.551-556
• /
• 2005

Wiskott-Aldrich syndrome(WAS) is an X-linked recessive immunodeficiency characterized by thrombocytopenia with small platelet volume, eczema, and recurrent infections, and is also characterized by increased incidence of auto immune diseases and malignancies. The phenotype observed in this syndrome is caused by mutation in the Wiskott-Aldrich syndrome protein(WASP) gene localized to the proximal short arm of the X chromosome and recently isolated through positional cloning. The gene encodes a 502 amino acid protein, which contains 12 exons and spans 9 kb of genomic DNA. The function of the encoded protein is not well understood. The clinical diagnosis of WAS can be difficult and is usually confirmed by the detection of WASP gene mutations and the expression of WSAP in patient blood sample using genetic analysis. We reported a case of a 13-month old boy with WAS who was identified with the novel mutation in exon 2 of WASP gene by direct sequencing and the complete absence of WASP expression by immunoblotting.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.10
• /
• pp.5113-5117
• /
• 2012

Prohibitin (PHB) is a chaperone protein which is highly conserved evolutionarily. It shows significant homology with the Drosophila cc gene which is considered important for development and differentiation of Drosophila melanogaster. Investigations have revealed an involvement of PHB in cellular proliferation and development, apoptosis, signal transduction, mitochondrial function and regulation of the estrogen and androgen receptors. Therefore, we conducted the present study to analyze mutations in the highly conserved region in Indian female breast cancer patients. Conventional PCR-SSCP and Automated DNA sequencing were performed with a total of 105 breast cancer samples along with adjacent normal tissue. Of the total, 14.2% (15/105) demonstrated a mutation status of prohibitin observed in our study population. We identified a novel missense mutation (Thr>Ser), a novel deletion of T nucleotide in an intron adjacent to intron-exon boundary and a previously determined missense mutation (Val>Ala). A statistically significant correlation was obtained which suggested that prohibitin may be associated with tumor development and/or progression of at least some proportion of breast cancers.

• Asian Pacific Journal of Cancer Prevention
• /
• v.17 no.7
• /
• pp.3627-3629
• /
• 2016

Background: Activation and inactivation of nuclear factor of kappa light chain gene enhancer in B cells (NFKB) is tightly regulated to ensure effective onset and cessation of defensive inflammatory signaling. However, mutations within NFKB, or change in activation and inactivation molecules have been reported in a few cancers. Although oral squamous cell carcinoma is one of the most prevalent forms of cancer in India, with a development associated with malignant transformation of precancerous lesions, the genetic status of NFKB and relative rates of change in oral precancerous lesions remain unknown. Hence in the present study we investigated all twenty four exons of NFKB gene in two precancerous lesions, namely oral submucous fibrosis (OSMF) and oral leukoplakia (OL) to understand its occurrence, incidence and assess its possible contribution to malignant transformation. Materials and Methods: Chromosomal DNA isolated from twenty five each of OSMF and OL tissue biopsy samples were subjected to PCR amplification with intronic primers flanking twenty four exons of the NFKB gene. The PCR amplicons were subsequently subjected to direct sequencing to elucidate the mutation status. Results: Sequence analysis identified a novel heterozygous mutation, c.419T>A causing substitution of leucine with glutamine at codon 140 (L140Q) in an OL sample. Conclusions: The identification of a substitution mutation L140Q within the DNA binding domain of NFKB in OL suggests that NFKB mutation may be relatively an early event during transformation. To the best of our knowledge, this study is the first to have identified a missense mutation in NFKB in OL.

• BMB Reports
• /
• v.40 no.1
• /
• pp.15-21
• /
• 2007

Breast cancer is the most common malignancy among women, and mutations in the BRCA1 gene produce increased susceptibility to these malignancies in certain families. In this study, the forward 1-13 exons of breast cancer associated gene BRCA1 were cloned from breast cancer cell line ZR-75-30 by RT-PCR method. Sequence analysis showed that nine BRCA1 splice forms were isolated and characterized, compared with wild-type BRCA1 gene, five splice forms of which were novel. These splice isoforms were produced from the molecular mechanism of 5' and 3' alternative splicing. All these splice forms deleting exon 11b and the locations of alternative splicing were focused on two parts:one was exons 2 and 3, and the other was exons 9 and 10. These splice forms accorded with GT-AG rule. Most these BRCA1 splice variants still kept the original reading frame. Western blot analysis indicated that some BRCA1 splice variants were expressed in ZR-75-30 cell line at the protein level. In addition, we confirmed the presence of these new transcripts of BRCA1 gene in MDA-MB-435S, K562, Hela, HLA, HIC, H9, Jurkat and human fetus samples by RT-PCR analysis. These results suggested that breast cancer associated gene BRCA1 may have unexpectedly a large number of splice variants. We hypothesized that alternative splicing of BRCA1 possibly plays a major role in the tumorigenesis of breast and/or ovarian cancer. Thus, the identification of cancer-specific splice forms will provide a novel source for the discovery of diagnostic or prognostic biomarkers and tumor antigens suitable as targets for therapeutic intervention.

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

• BMB Reports
• /
• v.52 no.2
• /
• pp.157-162
• /
• 2019

Our previous study found that two novel cancer-related genes, PRR11 and SKA2, constituted a classic gene pair that was regulated by p53 and NF-Y in lung cancer. However, their role and regulatory mechanism in breast cancer remain elusive. In this study, we found that the expression levels of PRR11 and SKA2 were upregulated and have a negative prognotic value in breast cancer. Loss-of-function experiments showed that RNAi-mediated knockdown of PRR11 and/or SKA2 inhibited proliferation, migration, and invasion of breast cancer cells. Mechanistic experiments revealed that knockdown of PRR11 and/or SKA2 caused dysregulation of several downstream genes, including CDK6, TPM3, and USP12, etc. Luciferase reporter assays demonstrated that wild type p53 significantly repressed the PRR11-SKA2 bidirectional promoter activity, but not NF-Y. Interestingly, NF-Y was only essential for and correlated with the expression of PRR11, but not SKA2. Consistently, adriamycin-induced (ADR) activation of endogenous p53 also caused significant repression of the PRR11 and SKA2 gene pair expression. Notably, breast cancer patients with lower expression levels of either PRR11 or SKA2, along with wild type p53, exhibited better disease-free survival compared to others with p53 mutations and/or higher expression levels of either PRR11 or SKA2. Collectively, our study indicates that the PRR11 and SKA2 transcription unit might be an oncogenic contributor and might serve as a novel diagnostic and therapeutic target in breast cancer.