• BMB Reports
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• v.43 no.3
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• pp.193-198
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• 2010

In this study, we report the identification and characterization of a novel C2H2 zinc finger protein, ZNF552, from a human embryonic heart cDNA library. ZNF552 is composed of three exons and two introns and maps to chromosome 19q13.43. The cDNA of ZNF552 is 2.3 kb, encoding 407 amino acids with an amino-terminal KRAB domain and seven carboxyl-terminal C2H2 zinc finger motifs in the nucleus and cytoplasm. Northern blotting analysis indicated that a 2.3 kb transcript specific for ZNF552 was expressed in liver, lung, spleen, testis and kidney, especially with a higher level in the lung and testis in human adult tissues. Reporter gene assays showed that ZNF552 was a transcriptional repressor, and overexpression of ZNF552 in the COS-7 cells inhibited the transcriptional activities of AP-1 and SRE, which could be relieved through RNAi analysis. Deletion studies showed that the KRAB domain of ZNF552 may be involved in this inhibition.

• Archives of Pharmacal Research
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• v.25 no.3
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• pp.364-369
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• 2002

Hepatitis C virus (HCV) is remarkably efficient at establishing chronic infection. One of the reasons for this appears to be the suppression of the accessory cell function of professional antigen presenting cells. In the present study, the immunosuppressive activity of HCV protein was examined on dendritic cells (DCs) generated from mouse bone marrow progenitor cells in vitro. We found that the DCs forced to express HCV protein have defective allostimulatory ability. DCs expressing HCV protein were phenotypically indistinguishable from normal DCs. However, they were unable to produce IL-12 effectively when stimulated with lipopolysaccharide. The functional domain of the HCV protein essential for immunosuppression was determined using a series of ${NH_2}-and$ C-terminal deletion mutants of HCV core protein. We found that amino acid residues residing between the 21 st and the 40th residues from the ${NH_2}-terminus$ of HCV core protein are required for immunosuppression. These findings suggest that HCV core protein suppresses the elicitation of protective Th1 responses by the inhibition of IL-12 production by DCs.

• Korean Journal of Animal Reproduction
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• v.20 no.4
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• pp.453-458
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• 1997

It is known that the incorporation of genes into transgenic mice is generally stable and is p passed on to succeeding generations in a Mendelian fashion. In this report, transgenic mice were set as a model to evaluate whether the transgenes are transmitted in a Mendelian principle in a successive generations and how they are tran s smitted into their offspring. A 3.0 kb linear DNA fragment, containing the MMTV LTR, bovine aSI casein cDNA and SV 40 splicing and polyadenylation site; was microinjected into fertilized mouse embryos. The tail DNAs of the resulting pups were subjected to dot and Southern hybridizations to screen transgenic founders. The DNAs of their offspring were anlyzed by PCR to confirm the transmission of the transgene from F0. Out of 72 live pups four pups (5.6%), 3 males and 1 female, were positive for the transgene. The rates of transmission from F0 into F1 were 33.3, 7.7, 0, and 62.5%. Those from F1 into F2 were 63.6, 5.9, and 68.8% and those from F2 into F3 were 85.7, and 88.2%. In this report, the transmission pattern of transgenes in transgenic mice into their offspring was demonstrated. It either follows or does not follow in a Mendelian fashion. Deletion or loss of the transgenes from F0 in some lines became apparant to the succeeding generations.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.54-54
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• 2001

Human chorionic gonadotropin (hCG) is a member of the glycoprotein hormone family which includes FSH, hCG, TSH. These hormone family is characterized by a heterodimeric structure composed a common $\alpha$-subunit noncovalently linked to a hormone specific $\beta$-subunit. The correct conformation of the heterodimer is also important for efficient secretion, hormone-specific post-translational modifications, receptor binding and signal transduciton. To determine $\alpha$ and $\beta$-subunits can be synthesized as a single polypeptide chain (tethered-hCG) and also display biological activity, the tethered-hCG molecule by fusing the carboxyl terminus of the hCG $\beta$-subunit to the amino terminus of the $\alpha$-subunit was constructed and transfected into chinese hamster ovary (CHO-K1) cells. We also constructed C-terminal deletion mutants (D9l, D89, D88, D87, D86, D84, D83) of single chain hCG to determine the biological function (secretion, LH-activity, receptor binding, cAMP production) of these mutants. Between six and eight stably transfected pools of cells expressing wild type and mutant hCGs were selected for neomycin resistant. The hCGs secreted by the stably transfected cells into serum-free media were collected and quantified by radioimmunoassay, as described in protocol (DPC(hCG IRMA). LH activity was in terms of testosterone production and aromatase activity in primary cultured rat Leydig cells. The tethered-wthCG was efficiently secreted and showed similar LH-like activity to the dimeric hCG. The D83hCG mutant was not detected in this assay. It is suggest that hCG C-terminal part is very important for hCG secretion. Now, we checking the LH-like activity of these mutant hCGs. These data indicate that the constructs of tethered molecule will be useful in the study of mutants that affect subunit association and/or secretion.

• Molecules and Cells
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• v.28 no.6
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• pp.553-558
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• 2009

In the periphery, a galectin-1 receptor, CD7, plays crucial roles in galectin-1-mediated apoptosis of activated T-cells as well as progression of T-lymphoma. Previously, we demonstrated that $NF-{\kappa}B$ downregulated CD7 gene expression through the p38 MAPK pathway in developing immature thymocytes. However, its regulatory pathway is not well understood in functional mature T-cells. Here, we show that CD7 expression was downregulated by Twist2 in Jurkat cells, a human acute T-cell lymphoma cell line, and in EL4 cells, a mature murine T-cell lymphoma cell line. Furthermore, ectopic expression of Twist2 in Jurkat cells reduced galectin-1-induced apoptosis. While full-length Twist2 decreased CD7 promoter activity, a C-terminal deletion form of Twist2 reversed its inhibition, suggesting an important role of the C-terminus in CD7 regulation. In addition, CD7 expression was enhanced by histone deacetylase inhibitors such as trichostatin A and sodium butyrate, which indicates that Twist2 might be one of candidate factors involved in histone deacetylation. Based on these results, we conclude that upregulation of Twist2 increases the resistance to galectin-1-mediated-apoptosis, which may have significant implications for the progression of some T-cells into tumors such as Sezary cells.

• The Korean Journal of Physiology and Pharmacology
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• v.23 no.3
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• pp.219-227
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• 2019

Polycystic kidney disease 2-like-1 (PKD2L1), polycystin-L or transient receptor potential polycystin 3 (TRPP3) is a TRP superfamily member. It is a calcium-permeable non-selective cation channel that regulates intracellular calcium concentration and thereby calcium signaling. Although the calmodulin (CaM) inhibitor, calmidazolium, is an activator of the PKD2L1 channel, the activating mechanism remains unclear. The purpose of this study is to clarify whether CaM takes part in the regulation of the PKD2L1 channel, and if so, how. With patch clamp techniques, we observed the current amplitudes of PKD2L1 significantly reduced when co-expressed with CaM and $CaM{\triangle}N$. This result suggests that the N-lobe of CaM carries a more crucial role in regulating PKD2L1 and guides us into our next question on the different functions of two lobes of CaM. We also identified the predicted CaM binding site, and generated deletion and truncation mutants. The mutants showed significant reduction in currents losing PKD2L1 current-voltage curve, suggesting that the C-terminal region from 590 to 600 is crucial for maintaining the functionality of the PKD2L1 channel. With PKD2L1608Stop mutant showing increased current amplitudes, we further examined the functional importance of EF-hand domain. Along with co-expression of CaM, ${\triangle}EF$-hand mutant also showed significant changes in current amplitudes and potentiation time. Our findings suggest that there is a constitutive inhibition of EF-hand and binding of CaM C-lobe on the channel in low calcium concentration. At higher calcium concentration, calcium ions occupy the N-lobe as well as the EF-hand domain, allowing the two to compete to bind to the channel.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.3
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• pp.651-656
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• 2006

Activation of $NF-{\kappa}B$ is known to be a trigger of various cellular disorders including inflammatory and autoimmune diseases such as rheumatoid arthritis. Numerous approaches are ongoing within laboratories to identify potential therapeutic agents which inhibit the $NF-{\kappa}B$ activation. In this study, we have tested the inhibitory effects of five traditional medicines on the activation of $NF-{\kappa}B$ by NIK. Among three medicines which exhibited inhibitory effect on the expression of $NF-{\kappa}B$ repoter plasmid, we investigated further the inhibitory mechanism of Dichroa febrifuga in connection with IKKY activity. Wild type $IKK{\gamma}$ inhibited the $NF-{\kappa}B$ activation by NIK but the C-terminal deletion mutant of IKKY did not show the inhibitory effect, indicating that the C-terminal leucine zipper domain of $NF-{\kappa}B$ is important for the inhibition of $NF-{\kappa}B$ activation. The water extract of Dichroa febrifuga(DFE) also strongly inhibited the $NF-{\kappa}B$ activation by NIK. The inhibitory activity of DFE appeared to be independent of the expression of $IKK{\gamma}$, suggesting that the pathways of inhibition by Dichroa febrifuga and $IKK{\gamma}$ are different. Our results suggest that Dichroa febrifuga can be used as a medicine for inhibition of the $NF-{\kappa}B$ activation in a wide range of cells without relation to the expression of $IKK{\gamma}$.

• KSBB Journal
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• v.20 no.1 s.90
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• pp.21-25
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• 2005

Paraquat, a widely used herbicide, has been suggested as a potential risk factor for Parkinson's disease. Heme oxygenase-1(HO-1), a marker for oxidative stress and endoplasmic reticulum(ER) stress, is known to catalyze heme to biliverdin, carbon monoxide and free iron in response to various stimuli. Here we show that paraquat activates HO-1 expression in a time-and dose-dependent manner in substantia nigra(SN) dopaminergic neuronal cells. Activation of Ho-1 by paraquat was regulated primarily at the level of gene transcription. Deletion analysis of the promoter and the 5' distal enhancers, E1 and E2, of the HO-1 gene revealed that the E2 enhancer is a potent inducer of the paraquat-dependent Ho-1 gene expression in dopamninergic neuronal cells. Mutational analysis of the E2 enhacer further demonstrated that the transcription factor activator protein-1(AP-1) plays an important role in mediating paraquat-induced HO-1 gene transcription. Moreover, using specific inhibitors of the mitogen-activated protein kinases(MAPKs), we investigated the role of paraquat and MAPKs for HO-1 gene regulation in dopaminergic cells. The c-Jun N-terminal kinase(JNK) inhibitor SP600125 significantly suppressed the expression of HO-1 by paraquat. All these results demonstrate that induction of HO-1 by paraquat requies the activation of the AP-1 and JNK pathway.

• Journal of Microbiology and Biotechnology
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• v.20 no.8
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• pp.1196-1203
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• 2010

In the present work, methanethiol and dimethyldisulfide were investigated as sulfur sources for methionine synthesis in Corynebacterium glutamicum. In silico pathway analysis predicted a high methionine yield for these reduced compounds, provided that they could be utilized. Wild-type cells were able to grow on both methanethiol and dimethyldisulfide as sole sulfur sources. Isotope labeling studies with mutant strains, exhibiting targeted modification of methionine biosynthesis, gave detailed insight into the underlying pathways involved in the assimilation of methanethiol and dimethyldisulfide. Both sulfur compounds are incorporated as an entire molecule, adding the terminal S-$CH_3$ group to O-acetylhomoserine. In this reaction, methionine is directly formed. MetY (O-acetylhomoserine sulfhydrylase) was identified as the enzyme catalyzing the reaction. The deletion of metY resulted in methionine auxotrophic strains grown on methanethiol or dimethyldisulfide as sole sulfur sources. Plasmid-based overexpression of metY in the ${\Delta}$metY background restored the capacity to grow on methanethiol or dimethyldisulfide as sole sulfur sources. In vitro studies with the C. glutamicum wild type revealed a relatively low activity of MetY for methanethiol (63 mU/mg) and dimethyldisulfide (61 mU/mg). Overexpression of metY increased the in vitro activity to 1,780 mU/mg and was beneficial for methionine production, since the intracellular methionine pool was increased 2-fold in the engineered strain. This positive effect was limited by a depletion of the metY substrate O-acetylhomoserine, suggesting a need for further metabolic engineering targets towards competitive production strains.

• Applied Biological Chemistry
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• v.36 no.6
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• pp.525-532
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• 1993

To characterize the prolamines in rice cultivars, the complete coding sequences of 17 prolamine genes from the database were analyzed. According to the phylogenic analysis of the sequences, these genes could be classified into 4 groups, Group I to IV. The multiple alignment of the deduced amino acid sequences revealed that the four groups differ from one another in chain length caused by deletion of short internal amino acids or carboxyl terminal fragments. Each group was also found to have different amino acid composition with 1, 4, 10 and 30% of sulfur containing amino acids (methionine and cysteine) in Group I to IV prolamines, respectively. Also the isoelectric points of these groups showed the different values of 9.2, 8.2, 6.7 and 7.4. Finally, from the analysis of codon usage pattern of prolamine genes, the codon usage for arginine, serine, threonine, isoleucine, asparagine, aspartic acid, glutamic acid and cysteine were higly biased. In the analysis of the codon usage pattern, the relation of the fraction of G/C ending codons to effective codon numbers suggests the different translational efficiency in the expression of the prolamine multigenes.