• Archives of Pharmacal Research
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• v.25 no.2
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• pp.208-213
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• 2002

The human polyomavirus JC virus is the etiologic agent of progressive multifocal leukoencephalopathy (PML). As the JC virus early promoter directs cell-specific expression of the viral replication factor large T antigen, transcriptional regulation constitutes a major mechanism of glial tropism in PML. It has been demonstrated that SV4O or JC virus large T antigen interacts with p53 protein and regulates many viral and cellular genes. In this study we founts that p53 represses the JC virus early promoter in both glial and nonglial cells To identify the cis-regulatory elements responsible for p53-mediated repression, deletional and site-directed mutational analyses were performed . Deletion of the enhancer region diminished p53-mediated transcriptional repression. However, point mutations of several transcription factor binding sites in the basal promoter region did not produce any significant changes. In support of this observation, when the enhancer was fused to a heterologous promoter, p53 red reduced the promoter activity about three fold. These results indicate that the enhancer region is important for tole repression of JC virus transcription by p53. Furthermore, coexpression of JC virus T antigen with a p53 protein abolished p53-mediated repression of the JC virus early promoter in non-glial cells, but not in glial cells. This finding suggests that T antigen interacts with p53 and regulates JC virus transcription in a cell-specific manner.

• BMB Reports
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• v.54 no.8
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• pp.425-430
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• 2021

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces coronavirus disease 2019 (COVID-19) and may increase the risk of adverse outcomes in lung cancer patients. In this study, we investigated the expression and function of mucin 1 (MUC1) after SARS-CoV-2 infection in the lung epithelial cancer cell line Calu-3. MUC1 is a major constituent of the mucus layer in the respiratory tract and contributes to pathogen defense. SARS-CoV-2 infection induced MUC1 C-terminal subunit (MUC1-C) expression in a STAT3 activation-dependent manner. Inhibition of MUC1-C signaling increased apoptosis-related protein levels and reduced proliferation-related protein levels; however, SARS-CoV-2 replication was not affected. Together, these results suggest that increased MUC1-C expression in response to SARS-CoV-2 infection may trigger the growth of lung cancer cells, and COVID-19 may be a risk factor for lung cancer patients.

• BMB Reports
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• v.30 no.2
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• pp.162-165
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• 1997

RNA I. a negative controller of ColE1-type plasmid replication, is metabolized by several RNases in Escherichia coli. Two small derivatives of RNA I are accumulated at nonpermissive temperatures in an E. coli strain carrying the rnpA49 mutation, a thermosensitive mutation in the rnpA gene encoding the protein component of RNase P. A primer extension analysis was carried out to compare 5' processing of RNA I in the E. coli rnpA49 cells at both permissive and nonpermissive temperatures. Derivatives of RNA I having different 5' ends were observed in the cells grown at permissive and nonpermissive temperatures. Some of the derivatives may be generated by the cleavage of RNase P.

• Journal of Microbiology and Biotechnology
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• v.11 no.5
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• pp.825-830
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• 2001

Escherichia coli, which harbored the ars operon from a plasmid pMH12 of Klebsiella oxytoca D12, showed filamentation due to the expression of ars genes in the presence of arsenite. The continued DNA replication in the absence of cell division was revealed, since nucleoids abound with DAPI appeared to be arranged in chains. In contrast to overexpression of arsA, its frame-shift mutant and knock-out mutant lost filamentation in the presence of arsenite, which suggested that ars-induced division block was dependent on expression of arsA. ArsA-induced division inhibition was not a consequence of an inhibition of DNA replication, and the inability of arsenite to induce an SOS response indicated that arsA-mediated division inhibition was dependent on the expression of the gene product encoded by the minB operon. ArsA is a peripheral membrane protein with an ATP-binding domain, which is homologous to MinD that requires ATP-dependent efflux. These results suggested that ArsA could possibly recruit MinC to the membrane and modulate cytoplasmic FtsZ to block assembly at the middle of the cell.

• Proceedings of the PSK Conference
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• 2001.04a
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• pp.48-55
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• 2001

When an elongating RNA polymerase encounters DNA damage on the template strand of a transcribed gene it can either be arrested by or be transcribed through the lesion. Lesions that arrest RNA polymerases are thought to be subject to transcription-coupled repair, whereas that damage that is bypassed can cause miscoding, resulting in mutations in the transcript (transcriptional mutagenesis). We have developed a technique using a plasmid-based luciferase reporter assay to determine the extent to which a particular type of DNA base modification is capable of causing transcriptional mutagenesis in vivo. The system uses Escherichia coli strains with different DNA repair backgrounds and is designed to detect phenotypic changes caused by transcriptional mutageneis under nongrowth conditions. In addition, this method is capable of indicating the extent to which a particular DNA repair enzyme (or pathway) suppresses the occurrence of transcriptional mutagenesis. Thus, this technique provides a tool with which the effects of various genes on non-replication-dependent pathways resulting in the generation of mutant proteins can be gauged.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.3
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• pp.386-393
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• 2004

This study was conducted to investigate the effects of feeding dried leftover food (DLF) on growth, body composition and feed conversion of broiler chicks. One hundred ninety-six of one-day old Ross broiler chicks were assigned to 7 treatments in a completely randomized design. Each treatment had four replications with seven chicks per replication. The treatments groups included control without DLF, dietary 10% level of DLF, dietary 20% level of DLF and dietary 30% level of DLF, 5% higher protein level of diet containing 10% DLF, 10% higher protein level of diet containing 20% DLF and 15% higher protein level of diet containing 30% DLF than control diet. Body weight gain was slightly higher in control group than that of DLF-fed groups. However, there were no significant differences in body weight gain among those groups fed diets containing different levels of DLF. In general, increasing dietary level of DLF resulted in decreasing feed conversion. Content of crude protein in whole broiler body was slightly higher in control group although any significant difference was not found among treatments (p>0.05). Content of crude fat in whole broiler body was lowest in groups fed diets containing 30% DLF with 15% higher protein level than control diet, showing significant difference from groups fed diets containing 20% DLF (p<0.05). Contents of total cholesterol, free cholesterol, cholesterol ester and LDL- cholesterol in blood of broilers fed DLF-containing diets generally appeared to be higher compared with control group without significant difference (p>0.05). Fatty acid contents in broiler meat were higher in the order of oleic acid, palmitic acid and linoleic acid without significant differences among treatments. Content of DHA in broiler meat was higher in groups fed diets containing DLF than that of control group although there were no significant differences among treatments (p>0.05).

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.4
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• pp.518-522
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• 2004

This experiment was conducted to investigate the effects of different levels of dried leftover food (DLF) in the diet on feed utilization and egg-laying performance of hens. One hundred sixty-eight, 18 week old Tetra brown commercial layers, were assigned to 7 treatments in a completely randomized design. Each treatment has four replications per treatment with six animals per replication. All the experimental animals were fed diets for 7 weeks. The treatments included 1) control group without DLF, 2) diet with 10% DLF, 3) diet with 20% DLF, 4) diet with 30% DLF, 5) 10% higher protein level of diet with 10% DLF, 6) 20% higher protein level of diet with 20% DLF and 7) 30% higher protein level of diet with 30% DLF. Average daily feed intake (ADFI) tended to be improved with DLF feeding. ADFI of group fed diets with 20% was significantly higher than that of control (p<0.05). Feed conversions of DLFfed groups were higher than that of control. Egg production tended to be higher in groups fed diets with 10% DLF than control diet without significant differences (p>0.05). However, those of groups fed diets containing 20 and 30% DLF were lower than that of control. Supplementing protein source to DLF-containing diets improved egg production (p<0.05). Increasing level of DLF in the diet for layer decreased egg weight and egg mass compared to control without significant differences (p>0.05). Protein supplementation to DLF-containing diets increased egg mass without significant difference (p>0.05). The range of egg cholesterol concentration of DLF-fed groups was 11.94-14.10 mg/g while that of control group was 12.31 mg/g although there was no significant difference among treatments (p>0.05).

• Proceedings of the Korean Society of Life Science Conference
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• 2001.09a
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• pp.82-82
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• 2001

• Genomics & Informatics
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• v.18 no.3
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• pp.32.1-32.7
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• 2020

The mitochondrial genome of a species is an essential resource for its effective conservation and phylogenetic studies. In this article, we present sequencing and characterization of the complete mitochondrial genome of a threatened labeonine fish, Cirrhinus reba collected from Khulna region of Bangladesh. The complete mitochondrial genome was 16,597 bp in size, which formed a circular double-stranded DNA molecule containing a total of 37 mitochondrial genes (13 protein-coding genes, 2 ribosomal RNA genes, and 22 transfer RNA genes) with two non-coding regions, an origin of light strand replication (OL) and a displacement loop (D-loop), similar structure with other fishes of Teleostei. The phylogenetic tree demonstrated its close relationship with labeonine fishes. The complete mitogenome of Cirrhinus reba (GenBank no. MN862482) showed 99.96% identity to another haplotype of Cirrhinus reba (AP013325), followed by 90.18% identity with Labeo bata (AP011198).

• Journal of Life Science
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• v.34 no.2
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• pp.86-93
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• 2024

Since replication of plasmids must be strictly controlled, plasmids that generally perform rolling circle replication generally maintain a constant copy number by strictly controlling the replication initiator Rep at the transcriptional and translational levels. Plasmid pJB01 contains three orfs (copA, repB, repC or repABC) consisting of a single operon. From analysis of amino acid sequence, pJB01 CopA was homologous to the Cops, as a copy number control protein, of other plasmids. When compared with a CopG of pMV158, CopA seems to form the RHH (ribbon-helix-helix) known as a motif of generalized repressor of plasmids. The result of gel mobility shift assay (EMSA) revealed that the purified fusion CopA protein binds to the operator region of the repABC operon. To examine the functional role of CopA on transcriptional level, 3 point mutants were constructed in coding frame of copA such as CopA R16M, K26R and E50V. The repABC mRNA levels of CopA R16M, K26R and E50V mutants increased 1.84, 1.78 and 2.86 folds more than that of CopA wt, respectively. Furthermore, copy numbers owing to mutations in three copA genes also increased 1.86, 1.68 and 2.89 folds more than that of copA wt, respectively. These results suggest that CopA is the transcriptional repressor, and lowers the copy number of pJB01 by reducing repABC mRNA and then RepB, as a replication initiator.