Biomedical subjects

Young-Mi Lee

Publications and source records attributed to Young-Mi Lee.

At least 19 recordsLinked to original sources

PubMed2007

Kinase-independent function of cyclin E.

E-type cyclins are thought to drive cell-cycle progression by activating cyclin-dependent kinases, primarily CDK2. We previously found that cyclin E-null cells failed to incorporate MCM helicase into DNA prereplication complex during G(0) --> S phase progression. We now report that a kinase-deficient cyclin E mutant can partially restore MCM loading and S phase entry in cyclin E-null cells. We found that cyclin E is loaded onto chromatin during G(0) --> S progression. In the absence of cyclin E, CDT1 is normally loaded onto chromatin, whereas MCM is not, indicating that cyclin E acts between CDT1 and MCM loading. We observed a physical association of cyclin E with CDT1 and with MCMs. We propose that cyclin E facilitates MCM loading in a kinase-independent fashion, through physical interaction with CDT1 and MCM. Our work indicates that-in addition to their function as CDK activators-E cyclins play kinase-independent functions in cell-cycle progression.

Animals↗

PubMed2006

Discoidin domain receptor 2 is involved in the activation of bone marrow-derived dendritic cells caused by type I collagen.

Discoidin domain receptors (DDRs), DDR1 and DDR2, are non-integrin receptor tyrosine kinases for collagen in many cell types. In this study, we investigated the contributions of DDRs to the activation of mouse bone marrow-derived dendritic cells (DCs) by type I collagen (ColI). Our data showed that transcript and protein of DDR2 were expressed constitutively in immature DCs and upregulated in TNF-alpha-stimulated mature DCs. ColI treatment induced DDR2 phosphorylation and subsequently induced the upregulation of IL-12 production, CD86 expression, and antigen uptake activity by immature DCs. Depletion of DDR2 by specific siRNA attenuated significantly an increase in expression of IL-12 and CD86 in ColI-treated DCs. Additionally, DDR2-ColI interaction upregulated the ability of mature DCs to activate allogeneic T cells. These findings suggest that DDR2 is a critical collagen receptor for DC activation and that DDR2-collagen interaction plays an important role in the functional capacity of DCs regulating immune responses.

Animals↗

PubMed2006

Environmental stressors (salinity, heavy metals, H2O2) modulate expression of glutathione reductase (GR) gene from the intertidal copepod Tigriopus japonicus.

Glutathione reductase (GR) plays an essential role in cell defense against reactive oxygen metabolites by sustaining the reduced status of an important antioxidant, glutathione. To address the effect of oxidative stresses on the intertidal copepod Tigriopus japonicus, we exposed specimens to hydrogen peroxide, heavy metals and different salinity levels, cloned and sequenced the oxidative stress-related GR gene. T. japonicus GR gene (Tigriopus GR) cDNA contained 1526 bp including an open reading frame (ORF) encoding 458 amino acids with a theoretical pI of 6.58 and a calculated molecular weight of 49.6 kDa. Tigriopus GR showed a high similarity to frog Xenopus laevis GR (identity 57%) and the filarial parasite, Onchocerca volvulus GR (identity 57%). Specific motifs such as flavin adenine dinucleotide-binding site (LVLGGGSGGIASARRAAEF), pyridine nucleotide-disulphide oxidoreductases class-I active site (GGTCVNVGCVP), and NADPH binding motif (GxGYIAx18Rx5R) were highly conserved in the deduced amino acid sequence of Tigriopus GR. Interestingly, its expression and enzyme characteristics were different from GR homologue of filarial parasite O. volvulus. To investigate the biochemical and enzymatic characteristics of Tigriopus GR protein, we constructed the expression vector, pCRT7/TOPO NT containing Tigriopus GR. Tigriopus pCRT7/TOPO NT/GR was expressed in Escherichia coli, and the soluble protein was purified by 6x His-tag chromatography. The recombinant Tigriopus GR enzyme was found to make homodimer complexes of approximately 108 kDa on 12% native gel electrophoresis and showed enzymatic activity with NADPH and oxidized glutathione (GSSG) as substrates. To analyze the gene expression of Tigriopus GR against different environmental stresses (hydrogen peroxide, salinity, and heavy metals), we performed real-time reverse transcriptase-polymerase chain reaction (real-time RT-PCR). Slight down-regulation in the expression of Tigriopus GR at the initial stage was observed upon exposure to hydrogen peroxide. The expression recovered in 2h, while there were significant changes upon heavy metal (Cu and Mn) exposures in a time-dependent manner. Also, Tigriopus GR expression was significantly increased with moderately high salt stress (24 and 40 ppt). In the case of low salt stress (0 and 12 ppt) the expression was found to be down-regulated. These findings provide a better understanding of cellular protection mechanisms in the intertidal copepod T. japonicus against the environmental stressors caused by non-optimal salt levels.

Amino Acid Sequence↗

PubMed2006

Essential role for cyclin D3 in granulocyte colony-stimulating factor-driven expansion of neutrophil granulocytes.

The proliferation of neutrophil granulocyte lineage is driven largely by granulocyte colony-stimulating factor (G-CSF) acting via the G-CSF receptors. In this study, we show that mice lacking cyclin D3, a component of the core cell cycle machinery, are refractory to stimulation by the G-CSF. Consequently, cyclin D3-null mice display deficient maturation of granulocytes in the bone marrow and have reduced levels of neutrophil granulocytes in their peripheral blood. The mutant mice are unable to mount a normal response to bacterial challenge and succumb to microbial infections. In contrast, the expansion of hematopoietic stem cells and lineage-committed myeloid progenitors proceeds relatively normally in mice lacking cyclin D3, revealing that the requirement for cyclin D3 function operates at later stages of neutrophil development. Importantly, we verified that this requirement is specific to cyclin D3, as mice lacking other G(1) cyclins (D1, D2, E1, or E2) display normal granulocyte counts. Our analyses revealed that in the bone marrow cells of wild-type mice, activation of the G-CSF receptor leads to upregulation of cyclin D3. Collectively, these results demonstrate that cyclin D3 is an essential cell cycle recipient of G-CSF signaling, and they provide a molecular link of how G-CSF-dependent signaling triggers cell proliferation.

Animals↗

PubMed2006

Inhibitory effects of tilianin on the expression of inducible nitric oxide synthase in low density lipoprotein receptor deficiency mice.

We investigated the effect of tilianin upon inducible nitric oxide synthesis in the plasma of low-density lipoprotein receptor knock-out (Ldlr-/-) mice fed with high cholesterol diet and in primary peritoneal macrophages of Ldlr-/- mice. High cholesterol diet induced nitric oxide production in the plasma of Ldlr-/- mice. Tilianin reduced the level of nitric oxide (NO) in plasma from Ldlr-/- mice induced by the high cholesterol diet. Tilianin also inhibited the NO production from the primary culture of peritoneal macrophages treated with lipopolysaccharide. The inhibition of NO production was caused by the suppression of inducible nitric oxide synthase (iNOS) gene expression in peritoneal macrophages isolated from Ldlr-/- mice. Moreover, tilianin inhibited the transcriptional activation of iNOS promoter that has NF-kappaB binding element. Thus, these results provide the first evidence that tilianin inhibit iNOS expression and production of NO and may act as a potential anti-inflammatory agent.

Animals↗

PubMed2006

Enhanced lycopene production in Escherichia coli engineered to synthesize isopentenyl diphosphate and dimethylallyl diphosphate from mevalonate.

To increase expression of lycopene synthetic genes crtE, crtB, crtI, and ipiHP1, the four exogenous genes were cloned into a high copy pTrc99A vector with a strong trc promoter. Recombinant Escherichia coli harboring pT-LYCm4 produced 17 mg/L of lycopene. The mevalonate lower pathway, composed of mvaK1, mvaK2, mvaD, and idi, was engineered to produce pSSN12Didi for an efficient supply of the lycopene building blocks, isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP). Mevalonate was supplied as a substrate for the mevalonate lower pathway. Lycopene production in E. coli harboring pT-LYCm4 and pSSN12Didi with supplementation of 3.3 mM mevalonate was more than threefold greater than bacteria with pT-LYCm4 only. Lycopene production was dependent on mevalonate concentration supplied in the culture. Clump formation was observed as cells accumulated more lycopene. Further clumping was prevented by adding the surfactant Tween 80 0.5% (w/v), which also increased lycopene production and cell growth. When recombinant E. coli harboring pT-LYCm4 and pSSN12Didi was cultivated in 2YT medium containing 2% (w/v) glycerol as a carbon source, 6.6 mM mevalonate for the mevalonate lower pathway, and 0.5% (w/v) Tween 80 to prevent clump formation, lycopene production was 102 mg/L and 22 mg/g dry cell weight, and cell growth had an OD(600) value of 15 for 72 h.

Carotenoids↗

PubMed2006

Molecular cloning and characterization of theta-class glutathione S-transferase (GST-T) from the hermaphroditic fish Rivulus marmoratus and biochemical comparisons with alpha-class glutathione S-transferase (GST-A).

We cloned and sequenced full-length cDNA of a theta-class-like glutathione S-transferase (GST-T) from liver tissue of the self-fertilizing fish Rivulus marmoratus. The full-length cDNA of rm-GST-T was 907 bp in length containing an open reading frame of 666 bp that encoded a 221-amino acid putative protein. Its derived amino acid sequence was clustered with other vertebrate theta-class GSTs in a phylogenetic tree. The deduced amino acid sequence of theta-like rm-GST (rm-GST-T) was compared with both classes (alpha and theta) of GST and alpha-class rm-GST (rm-GST-A). Tissue-specific expression of two rm-GST mRNAs was investigated using real-time RT-PCR. To further characterize the catalytic properties of this enzyme along with rm-GST-A, we constructed the recombinant theta-like rm-GST plasmid with a 6 x His-Tag at the N-terminal of rm-GST-T cDNA. Recombinant rm-GST-T was highly expressed in transformed Escherichia coli, and its soluble fraction was purified by His-Tag affinity column chromatography. The kinetic properties and effects of pH and temperature on rm-GST-T were further studied, along with enzyme activity and inhibition effects, and compared with recombinant rm-GST-A. These results suggest that recombinant rm-GSTs such as rm-GST-A and rm-GST-T play a conserved functional role in R. marmoratus.

Amino Acid Sequence↗

PubMed2006

Nonylphenol modulates expression of androgen receptor and estrogen receptor genes differently in gender types of the hermaphroditic fish Rivulus marmoratus.

To uncover the effect of estrogenic chemicals [4-nonylphenol (NP) and bisphenol A (BisA)] on the expression of androgen receptor (AR) and estrogen receptors (ERalpha and ERbeta) in the hermaphroditic fish Rivulus marmoratus, we cloned the full length of the cDNAs encoding AR, ERalpha, and ERbeta from gonadal tissue of R. marmoratus and analyzed the modulation of expression of these genes following exposure to estrogenic chemicals using real-time RT-PCR. R. marmoratus AR, ERalpha, and ERbeta genes showed a high similarity to the relevant fish species on amino acid residues, respectively. Rm-ERalpha and Rm-ERbeta cDNAs included a serine-rich region when compared to other teleost fish ER genes. Tissue-specific expression of Rm-AR and Rm-ERbeta mRNAs in adult hermaphrodite R. marmoratus was high in the gonad, while Rm-ERalpha mRNA was high in the liver based on real-time RT-PCR. In addition, Rm-AR and Rm-ERalpha mRNAs increased along with developmental stage from stage 3 (5 dpf) to hatching, while Rm-ERbeta mRNA increased from stage 2 (2 dpf). To uncover the effect of estrogenic chemicals on R. marmoratus, we exposed the fish to NP (300 microg/l) and BisA (600 microg/l) for 96 h. Significant down-regulation of Rm-AR, Rm-ERalpha, and Rm-ERbeta mRNA was observed in gonadal tissue after exposure to NP but not BisA. In the liver, there were gender differences in gene expression after EDC exposure. These results demonstrate that expression patterns of the Rm-AR, Rm-ERalpha, and Rm-ERbeta genes in the hermaphroditic fish, R. marmoratus, vary according to tissue and developmental stage as well as the specificity of environmental estrogenic chemicals. These genes can be useful as molecular biomarkers in assessing the potential impact of estrogenic compounds using this species as a model system.

Amino Acid Sequence↗

PubMed2006

Endocrine disrupting chemicals (bisphenol A, 4-nonylphenol, 4-tert-octylphenol) modulate expression of two distinct cytochrome P450 aromatase genes differently in gender types of the hermaphroditic fish Rivulus marmoratus.

To understand the effect of endocrine-disrupting chemicals (EDCs) on cytochrome P450 aromatase (rm-cyp19) gene expression between gender types in the hermaphroditic fish Rivulus marmoratus, we cloned two distinct rm-cyp19 genes using RT-PCR with degenerative primers, obtained full-length cDNAs using 5'- and 3'-RACE-PCR methods, and completely sequenced them. The brain aromatase (rm-cyp19b) cDNA consisted of 2,124 bp including the open reading frame (ORF), which encoded a putative protein of 505 amino acids. The ovarian aromatase (rm-cyp19a) cDNA consisted of 2,075 bp, including the ORF encoding a putative protein of 516 amino acids. Expression patterns of rm-cyp19b and rm-cyp19a mRNAs were investigated in embryos of different developmental stages and in seven different tissues of adult fish. The rm-cyp19b gene in hermaphrodite and secondary male R. marmoratus was predominantly expressed in the brain, while the rm-cyp19a gene was expressed gender-specifically in the gonad. The expression of rm-cyp19b mRNA increased from stage 1 (2 d post fertilization) to stage 4 (12 d post fertilization) in a developmental stage-dependent manner but steeply decreased in the hatching stage. Compared to the rm-cyp19b gene, the abundance of ovarian aromatase rm-cyp19a transcripts was very low, and its expression was first detected at stage 3 and then decreased gradually to the hatching stage. Alteration of rm-cyp19b and rm-cyp19a gene expression was further analyzed in the brain and gonad by real-time RT-PCR 96 h after EDC exposure in hermaphrodites and secondary males. The brain aromatase rm-cyp19b gene was up-regulated in the brain after 4-nonylphenol (4-NP)-exposure, while the ovarian aromatase rm-cyp19a gene was significantly down-regulated in the gonad. In 300 microg/L 4-tert octylphenol (4-tert-OP), or 600 microg/L bisphenol A-exposed brain and gonad, both rm-cyp19b and rm-cyp19a genes were up-regulated. In the case of secondary males, the rm-cyp19b gene was highly expressed in the 4-NP-exposed brain, while expression of the rm-cyp19a gene was not detected in the gonad. These results indicate that the expression of rm-cyp19a and rm-cyp19b genes is differently modulated according to estrogenic compounds and gender type of R. marmoratus.

Animals↗

PubMed2006

Cloning and characterization of glutathione S-transferase gene in the intertidal copepod Tigriopus japonicus and its expression after exposure to endocrine-disrupting chemicals.

To investigate the impacts of marine pollution on aquatic organisms, we tested the intertidal copepod Tigriopus japonicus as a model species. To analyze the copepods' responses to endocrine-disrupting chemicals (EDCs), we exposed them to two different chemicals: 4,4'-octylphenol (4,4'-OP, 12.5-100 microg/L for 2 h) and polychlorinated biphenyl (PCB, 6.25-25 microg/L for two days). 4,4'-OP was toxic, although exposure time was limited to 2h. After extracting total RNA from the exposed T. japonicus, we performed reverse transcriptase-polymerase chain reaction (RT-PCR) to determine gene expression patterns following chemical exposure. To analyze the gene expression of T. japonicus, we used glutathione S-transferase with GAPDH as an internal control. Of the genes tested using EDC-exposed samples, 4,4'-OP induced upregulation of the glutathione S-transferase (GST) gene, while PCB caused downregulation of the GST gene. These results suggest that the two EDCs act in different manners in T. japonicus.

Animals↗

PubMed2006

Expression profiles of 4-nonylphenol-exposed medaka (Oryzias latipes) analyzed with a 3.4 K microarray.

Changes in gene expression in liver of medaka in response to 4-nonylphenol (4-NP) were investigated with a microarray consisting of 3.4 K medaka-specific cDNA probes. Upon exposure to 4-NP at two different concentrations (20 and 100 microg/L) for 24 h, we found 44 different genes that were up- or downregulated with statistically significant changes. Digestive enzyme genes were downregulated but vitellogenin, choriogenin and novel biomarker genes were upregulated. Additionally an analysis of the changes of gene expression with respect to time was conducted at 100 microg/L of 4-NP with samples at 0, 24, 48 and 96 h. The expression of 75 genes was altered and these were categorized into four different clusters. The validity of the results was checked by semi-quantitative PCR with 12 representative genes and this confirmed the microarray data. Therefore, we suggest that this medaka 3.4 K chip would be useful in generating gene expression profiles for studies of ecotoxicogenomics in medaka.

Animals↗

PubMed2006

Cloning of Ki-ras and Ha-ras cDNAs from the hermaphroditic fish Rivulus marmoratus (Cyprinodontiformes, Rivulidae) and its expression after exposure to 4-nonylphenol.

Previous studies on ras proto-oncogene genes in fish have been focused on chemical-associated carcinogenesis, and the expression of fish ras genes was not well-characterized. We investigated Ki- and Ha-ras genes from the hermaphroditic fish Rivulus marmoratus to understand better their expression patterns in specific tissues, as well as their responses to endocrine-disrupting chemicals such as 4-nonylphenol (4-NP). By investigating expression patterns, we found that the R. marmoratus Ki-ras (Rm Ki-ras) gene showed an alternative splicing event between exons 4A and 4B according to tissue types, which is different from the expression pattern of mammalian Ki-ras genes. In the Rm Ki-ras gene, there were two different expressed types, with exons 1-2-3-4A-4B (long form) and with exons 1-2-3-4B (short form). In the Rm Ki-ras gene, the long form was expressed strongly in the gonad and intestine, and the short form was expressed ubiquitously, except for a low level of expression in the liver. Following 4-NP exposure (300 microg/L), the Rm Ki-ras long form in the liver was significantly expressed, while it was expressed moderately in the ovaries. However, the Rm Ha-ras gene was significantly over-expressed in the brain, while its expression in the gonad was down-regulated. In relation to these modulations after 4-NP exposure, we searched the Rm Ha- and Ki-ras promoter regions and found several ERE-half sites, that may be involved in the modulation of ras gene expression following 4-NP exposure. These genes could be applicable as new biomarker genes for assessing exposure to endocrine-disrupting chemicals (EDCs). Further, this implies the disturbance of ras-dependent signal transduction following EDC exposure.

Alternative Splicing↗

PubMed2006

Inhibition of trypsin-induced mast cell activation by acanthoic acid.

Acanthoic acid (AA) is a pimaradiene diterpene isolated from the Korean medicinal plant, Acanthopanax koreanum (Araliaceae). In the present study, we examined whether AA has the inhibitory effect on the production of inflammatory mediators and activating signals induced in trypsin-treated human leukemic mast cell-1 (HMC-1). HMC-1 cells were stimulated with trypsin (100 nM) in the presence or absence of AA (1, 10, and 100 microg/ml). We assessed the production of TNF-alpha and tryptase by enzyme-linked immunosorbent assay (ELISA) or reverse transcription-PCR, ERK activation by Western blot, and NF-kappaB activation by gel shift assay. AA (10 and 100 microg/ml) significantly inhibited production of both TNF-alpha and tryptase in a dose-dependent manner in trypsin-stimulated HMC-1. Furthermore, AA inhibited ERK phosphorylation and NF-kappaB activation induced by trypsin treatment without blocking of trypsin activity even with 100 microg/ml. These results suggest that AA may inhibit the production of inflammatory mediators through inhibition of ERK phosphorylation and NF-kappaB activation pathway in human mast cells. It supports the evidence that AA may be used to blocks the development of inflammation caused from mast cells.

Cells, Cultured↗

PubMed2006

Anti-complementary activity of ursane-type triterpenoids from Weigela subsessilis.

A new ursane-type triterpenoid, weigelic acid (1), and seven known compounds, ursolic acid (2), ilekudinol A (3), corosolic acid (4), ilekudinol B (5), esculentic acid (6), pomolic acid (7), and asiatic acid (8) were isolated from the leaf and stem of Weigela subsessilis. The structure of the new triterpenoid was established as 1beta,2alpha,3alpha,23-tetrahydroxyurs-12-en-28-oic acid on the basis of spectroscopic analyses. In addition, the isolated compounds were evaluated for their anti-complement activity against the classical pathway of the complement system. Of these, compounds 1-2 and 4-8 exhibited anti-complement activity with IC50 values of 152, 90, 130, 51, 56, 4, and 163 microM, respectively, whereas 3 was inactive. This shows that a carboxylic group of ursane-type triterpenoids seems to play an important role in inhibiting the hemolytic activity of human serum against erythrocytes.

Animals↗

PubMed2006

Suppressive effect of non-anaphylactogenic anti-IgE antibody on the development of dextran sulfate sodium-induced colitis.

Inflammatory bowel disease (IBD) is a spectrum of immune-mediated chronic disorders of the intestine. Patients with IBD tend to exhibit significantly elevated levels of IgE in their serum. In general, the pathogenesis of IBD exhibits inflammatory events such as immunoglobulin E (IgE)-mediated hypersensitivity. We examined the effect of the non-anaphylactogenic anti-IgE antibody, which has been known to block IgE functions, in an animal model of ulcerative colitis induced by the oral intake of dextran sulfate sodium (DSS) for seven days. The non-anaphylactogenic anti-IgE antibody was subcutaneously injected on day 0 of DSS treatment. The disease activity index (DAI) was calculated by scoring intestinal states, including body weight loss, diarrhea, and rectal bleeding, and the activities of myeloperoxidase (MPO) and chymase were measured in the colon tissue. In addition, the expression of tumor necrosis factor (TNF)-alpha and cyclooxygenase (COX)-2 was determined by Western blotting. Administration of the anti-IgE antibody markedly reduced the histological damage to the colon and the DAI increment exhibited by the DSS-induced colitis. The anti-IgE antibody also significantly suppressed the activities of MPO and chymase as well as the expression of TNF-alpha and COX-2 in the DSS-treated colon tissue. Furthermore, the elevation of IgE levels in serum was induced by DSS and reduced by anti-IgE antibody injection. Thus, these results indicate that the IgE response played an important role in the clinical signs and the expression of inflammatory mediators in a colitis model caused by DSS treatment, suggesting that the non-anaphylactogenic anti-IgE antibody may be a useful therapeutic agent for ulcerative colitis.

Anaphylaxis↗

PubMed2005

The intertidal copepod Tigriopus japonicus small heat shock protein 20 gene (Hsp20) enhances thermotolerance of transformed Escherichia coli.

To understand the role of the Tigriopus japonicus Hsp20 gene, we isolated this gene from a whole body cDNA library and found two heat shock factor elements at the 5'-UTR. The transformed bacteria containing Tigriopus Hsp20 showed thermotolerance against heat shock (54 degrees C) with different ranges of time. The Tigriopus Hsp20 gene is comprised of 174 amino acid residues and shows similarity to Caenorhabditis elegans (27% identity), silkworm (24.1% identity), moth (24.1% identity), Mexican tetra (19.5% identity), zebrafish (19.5% identity), and spiny dogfish (17.2% identity) genes, but shows more similarity in the C-terminal region that contains an alpha-crystallin domain. Protein motifs such as an N-glycosylation site (67-70 NKSE) and a casein kinase II phosphorylation site were found in Tigriopus Hsp20. The genomic structure of the Tigriopus Hsp20 gene did not contain introns. To characterize the biochemical characteristics of the Tigriopus Hsp20 protein, we expressed Tigriopus Hsp20 in Escherichia coli and purified the soluble protein via 6x His-tag chromatography. To analyze the gene expression of Tigriopus Hsp20 against environmental stresses (e.g., water temperature and salinity), we performed a semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). On exposure to different salinities, significant change in the expression of Tigriopus Hsp20 was not observed. However, upon heat shock (30 degrees C), Tigriopus Hsp20 expression was significantly increased, but in the case of cold shock (4 or 10 degrees C), expression was likely downregulated. These findings provide a better understanding of cellular protection mechanisms against environmental stress such as heat shock.

5' Untranslated Regions↗

PubMed2005

Cloning and expression of alpha class glutathione S-transferase gene from the small hermaphroditic fish Rivulus marmoratus (Cyprinodontiformes, Rivulidae).

In order to assess its potential as a biomarker of aquatic pollution, an alpha class glutathione S-transferase gene (GSTalpha gene) was cloned from the small hermaphroditic fish Rivulus marmoratus. The R. marmoratus GSTalpha gene spanned 1.3 kb, consisting of 6 exons encoding 221 amino acid residues. It showed high similarity to zebrafish GST. We named this R. marmoratus GSTalpha gene as rm-GSTalpha. The cDNA of the rm-GSTalpha gene was also investigated for its phylogeny, tissue-specific and chemical-induced expression. Rm-GSTalpha was subcloned into a 6 x His-tagged pCRT7 TOPO TA expression vector to produce the recombinant 6 x His-tagged rm-GST protein. This will be used in future to raise an rm-GSTalpha antibody for use in the study of phase II metabolism involved in detoxification. We also exposed R. marmoratus to 300 microg/l of 4-nonylphenol in water, and found approximately 4-fold induction of R. marmoratus GSTalpha mRNA in the treated animals. In this paper, we discuss the characteristics of the R. marmoratus GSTalpha gene as well as its potential use in relation to environmental pollution.

Amino Acid Sequence↗

PubMed2005

cDNA cloning and expression of a cytochrome P450 1A (CYP1A) gene from the hermaphroditic fish Rivulus marmoratus.

We previously described the genomic structure of the cytochrome P450 1A (CYP1A) gene from the hermaphroditic fish Rivulus marmoratus [Kim, I.-C., Kim, Y.J., Yoon, Y.-D, Kawamura, S., Lee, Y.-S., Lee, J.-S., 2004a. Cloning of cytochrome P450 1A (CYP1A) genes from the hermaphroditic fish Rivulus marmoratus and the Japanese medaka Oryzias latipes. Mar. Environ. Res. 58, 125-129]. To further characterize R. marmoratus CYP1A, we cloned the cDNA sequence of a CYP1A gene from this species and also expressed its recombinant protein in an E. coli system. We exposed R. marmoratus to 4-nonylphenol, and found a small induction of CYP1A mRNA in the treated animals. In this paper, we discuss the characteristics of R. marmoratus CYP1A gene as well as its potential use in a biomonitoring assay.

Amino Acid Sequence↗