• Molecules and Cells
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• v.20 no.2
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• pp.247-255
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• 2005

Three different catalase cDNA clones (CaCat1, CaCat2, and CaCat3) were isolated from hot pepper (Capsicum annuum L.), and their expression patterns were analyzed at the levels of mRNA and enzyme activity. Northern hybridization showed that the three catalase genes were differentially expressed in various organs, and that expression of CaCat1 and CaCat2 was regulated differently by the circadian rhythm. In situ hybridization revealed different spatial distributions of CaCat1 and CaCat2 transcripts in leaf and stem. In response to wounding and paraquat treatment, CaCat1 mRNA increased at 4-12 h in both paraquat-treated and systemic leaves. In contrast, wounding had no significant effect on expression of the catalase genes. The increase of catalase activity in the paraquat-treated and systemic leaves paralleled that of CaCat1 mRNA, but did not match that of CaCat1 mRNA in paraquat-treated stems. Our results suggest that CaCat1 may play a role in responses to environmental stresses.

• Journal of Microbiology and Biotechnology
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• v.7 no.1
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• pp.21-24
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• 1997

Chloramphenicol acetyl transferase (CAT) protein and mRNA levels in E. coli were determined following induction of a tac::cat construct by isopropyl-${\beta}$-thiogalactopyranoside (IPTG). High cat mRNA levels did not directly reflect CAT protein levels, in either shakeflask experiments or fermentations. Furthermore, concentrations of IPTG resulting in the highest levels of expression of cat mRNA, were different to those resulting in highest levels of CAT protein. The data suggest that high transcriptional activities lead to limitations at the translational level.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.188-188
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• 1996

In order to gain insight into the mechanism of the regulation of cytochrome P450IAl by arylhydrocarbon, the 5'-flanking region of a trout CYP450IAl 5'flanking DNA was cloned into pCAT-basic vector and it was transfected into Hepa-1 cells. 3MC treatment to hepa Ⅰ cells transfected with fish CYP450IAl-CAT construct results in mRNA increased by 2.81 fold when it was compared with that of control This increase of mRNA was decreased by concomitantly treated flavonoids such as morin. The levels of CAT mRNA that was treated with morin was 29.2-58.0% of 3MC stimulated CAT mRNA. Further investigation to find out if there are DRE, XRE or negative regulatory cis element in CYP450IA1 gene was undertaken. Results of the deletion study of 5'flanking DNA of trout P450IA indicate the existance of the negative(-1600 ～ -1300). CAT mRNA was about two-fold higher in deleted trout CYP450IAl-CAT construct transfected cells compared to the wi Id type trout CYP450IAl-CAT construct transfected cells. And The stimulatory effect of 3MC was no longer observed in col Is containing deleted CAT construct. [Supported by grants from the Korean Ministry of Education]

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.04a
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• pp.128-128
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• 1995

To investigate the mechanism of the regulation of cytochrome P450IA1 gene expression, ethoxyresorufin deethylase(EROD) and benzo(a)pyrene hydroxylase in B6 mouse liver, in isolated perfused rat liver system. and in B6 mouse hepatocyte Hepa-I cells were examined. In C57BL/6N mouse, 3-methylcholan- throne( 3MC ) treatment have resulted in the stimulation of EROD activity based on fluorometry by 2.79 fold comparirng with that of control. Measurement of mRNA of cytochrome P450 was carried out by either nothern blot or dot blot analysis. Findings are similar to that of studies with enzymes. Furhtermore, when RTPCR method was applied to detect mRNA in Hepa I cell and liver tissues the results were more clear. Cytochrome P450IA1 upstream DNA containing CAT construct was transfected into Hepa-1 cells. After transfection of CAT construct, 3MC and flavonoids, such as, chrysin, hesperetin, kaempferol, morin, myricetin and aminoyrine were treated. 48 Hours after treatments, cells were harvested and assayed for CAT mRNA by RTPCR. 3MC treatment to hepa I cells transfected with trout P450IA1-CAT construct increased CAT mRNA by 2.81 fold when it was compared with that of control. This increase CAT mRNA was decreased by concomitantly treated flavonoids and aminopyrine. The level of CAT protein was 29.2-58.0% of 3MC stimulated CAT protein. Results of this study suggested that RTPCR seems to be a very good method to study regulation of gene expression in liver tissue or Hepa cells.

• Korean Journal of Microbiology
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• v.44 no.4
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• pp.271-276
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• 2008

Ribosome stalling by nascent sticky peptide has been reported in several organisms across the kingdom. To test whether small subunit (SSU) rRNA is involved in this phenomenon, we developed a genetic system that utilized the specialized ribosome system to isolate SSU rRNA mutants that enable ribosomes to bypass the SecM-derived sticky peptide in protein synthesis. In this system, CAT-SecM mRNA, which encodes CAT protein containing the sticky peptide derived from SecM, is only translated by specialized ribosomes. These ribosomes were shown to transiently stall on CAT-SecM mRNA followed by the synthesis of the sticky peptide. Expression of specialized ribosomes resulted in the decreased steady-state level of CAT-SecM mRNA, which is consistent with a notion that ribosome stalling induces mRNA degradation. Isolation and characterization of SSU rRNA mutations using this genetic system that are sufficient to circumvent ribosome stalling induced by the SecM-derived sticky peptide will provide evidence of SSU rRNA function in mRNA cleavage.

• Archives of Pharmacal Research
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• v.20 no.5
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• pp.404-409
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• 1997

Trout CYP1A-CAT expression construct was generated by cloning -3.5 Kb $5^I$ flanking DNA of trout liver CYP1A gene in front of CAT gene at pCAT-basic vector. Hepa 1 cells, which are known to contain a functional arylhydrbcarbon $receptor^I$ were transfected with trout CYP1A-CAT using lipofectin. 3-Methylcholanthrene (1 nM) was added into hepa 1 cells in culture in order to examine if $5^I$ flanking DNA of trout CYP1A gene could interact with mouse transactivating factors to bring about transcription of the chloramphenicol acetyltransferase(CAT) reporter gene. The level of CAT protein was measured by CAT ELISA and the level of CAT mRNA was determined by RTPCR. The treatment of 1 nM 3-methylcholanthrene resulted in two fold increases in CAT protein as well as CAT mRNA compared to untreated control hepa 1 cells. These data indicate that arylhydrocarbon receptors of mouse hepa 1 cells are functional to activate exogenously transfected trout CYP1A-CAT construct in terms of both transcription and translation of CAT. We also examined the effect of 3-methylcholanthrene on endogenous cyplal activity in hepa 1 cell. 3-Methylcholanthrene (1 nM) treatment to hepa 1 cells trahsfected with trout CYP1A-CAT construct stimulated the level of cyp1a1 mRNA by two folds and the activity of ethoxyresorufin-O-deethylase by two fold compared to that of control cells. In this study we reported that trout CYP1A-CAT reporter gene expression construct could be expressed by 3-methylcholanthrene treatment in mouse hepa 1 cells. Thus trout CYP1A-CAT could serve as a good model to study the mechanism of regulation of CYP1A1 gene expression.

• Mycobiology
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• v.41 no.3
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• pp.145-148
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• 2013

Vegetative growth signaling of the opportunistic human pathogenic fungus Aspergillus fumigatus is mediated by GpaA ($G{\alpha}$). FlbA is a regulator of G protein signaling, which attenuates GpaA-mediated growth signaling in this fungus. The flbA deletion (${\Delta}flbA$) and the constitutively active GpaA ($GpaA^{Q204L}$) mutants exhibit enhanced proliferation, precocious autolysis, and reduced asexual sporulation. In this study, we demonstrate that both mutants also show enhanced tolerance against $H_2O_2$ and their radial growth was approximately 1.6 fold higher than that of wild type (WT) in medium with 10 mM $H_2O_2$. We performed quantitative PCR (qRT-PCR) for examination of mRNA levels of three catalase encoding genes (catA, cat1, and cat2) in WT and the two mutants. According to the results, while levels of spore-specific catA mRNA were comparable among the three strains, cat1 and cat2 mRNA levels were significantly higher in the two mutants than in WT. In particular, the ${\Delta}flbA$ mutant showed significantly enhanced and prolonged expression of cat1 and precocious expression of cat2. In accordance with this result, activity of the Cat1 protein in the ${\Delta}flbA$ mutant was higher than that of $gpaA^{Q204L}$ and WT strains. For activity of the Cat2 protein, both mutants began to show enhanced activity at 48 and 72 hr of growth compared to WT. These results lead to the conclusion that GpaA activates expression and activity of cat1 and cat2, whereas FlbA plays an antagonistic role in control of catalases, leading to balanced responses to neutralizing the toxicity of reactive oxygen species.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.5
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• pp.712-720
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• 2009

The goal of this study was to elucidate the expression and segmental distribution of the glomerular cationic amino acid metabolism transporter-2 (CAT-2) and thus to improve our understanding of porcine cationic amino acid transporters and amino acid absorption. Porcine CAT-2 was cloned, sequenced and characterized. The predicted amino acid sequence of porcine CAT-2 shared 86.1% and 92.1% identity with human and mouse CAT-2A, respectively. The tissue distribution patterns and ontogenic changes of CAT-2 mRNAs were determined by real-time Q-PCR. The results showed that porcine CAT-2 was highly expressed in the heart and intestinal tract (duodenum, ileum and jejunum). In addition, the mRNA of CAT-2 was found in liver, lung, kidney, brain and muscle. Within the intestinal tract, CAT-2 mRNA was most abundant in the ileum and rarely expressed in the duodenum. In the duodenum, the levels of CAT-2 mRNA reached their peak on day 7 (p<0.05) while in the jejunum, levels were low on day 1 and 7 and increased rapidly after day 26 before peaking on days 30 and 60 (p<0.05). The levels then dramatically decreased by day 90 (p<0.05). In the ileum, levels achieved their maximum on day 30 and then decreased significantly on day 60 (p<0.05).

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.10a
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• pp.153-155
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• 1995

To investigate the mechanism of the regulation of cytochrome P450IAl, the 5'-flanking region of a trout cytochrome P4501Al was cloned into the CAT basic expression vector at HindⅢ site. This trout Cytochrome P450IAl upstream DNA containing CAT construct was transfected into Hepa-1 cells .3MC treatment to hepa I cells transfected with trout P450IAl-CAT construct increased CAT protein and mRNA by 2.81 fold when it was compared with that of control. This increase CAT protein and mRNA was decreased by concomitantly treated flavonoids and aminopyrine. The level of CAT protein was 29.2-58.0% of 3MC stimulated CAT protein.

• Korean Journal of Ichthyology
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• v.9 no.1
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• pp.91-98
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• 1997

The transgene, pFV4CAT, containing CAT reporter gene regulated by carp $\beta$-actin promoter, was expressed in independent transgenic mud loach germ lines, determined by reverse transcriptase-PCR (RT-PCR) and enzyme-linked immunosorbant assay (ELISA). Expression of the transmitted transgene was found to be tissue-specific in F1 and F2 generations. Tissue specificity of the expression was dependent on each transgenic line with reproducible patterns. Liver and spleen did express the transgene more frequently than other tissues tested, and muscle and heart revealed the higher amount of CAT than other tissues, while testes showed the lowest expression level. The highest level of CAT expression in muscle from a transgenic F1 line was corresponding to 68-fold compared to the basal levels of controls.