• 제목/요약/키워드: transient gene expression

검색결과 201건 처리시간 0.022초

쌀 Glutelin 유전자군의 구조 및 발현조절 (Sturcture of the Rice Glutelin Multigene Family and Its Expression)

  • 황영수
    • 한국식물학회:학술대회논문집
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    • 한국식물학회 1987년도 식물생명공학 심포지움 논문집 Proceedings of Symposia on Plant Biotechnology
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    • pp.261-282
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    • 1987
  • Plants store a significant amount of their nitrogen, sulfur and carbon reserves as storage proteins in seed tissues. The major proteins present in rice seeds are the glutelins. Glutelins are initially synthesized at 4-6 days postanthesis and deposited into protein bodies via Golgi apparatus. Based on nucleic acid sequences and Southern blot analysis, the three isolated glutelin genomic clones were representative members of three gene subfamilies each containing 5 to 8 copies. A comparison of DNA sequences displayed by relevant regions of these genomic clones showed that two subfamilies, represented by clones, Gt1 and Gt2, were closely, related and probably evolved by more recent gene duplication events. The 5' flanking and coding sequences of Gt1 and Gt2 displayed at least 87% homolgy. In contrast, Gt3 showed little or no homolgy in the 5' flanking sequences upstream of the putative CAAT boxes and exhibited significant divergence in all other portions of the gene. Conserved sequences in the 5' flanking regions of these genes were identified and discussed in light of their potential regulatory role. The derived primary sequences of all three glutelin genomic clones showed significant homology to the legume 11S storage proteins indicating a common gene origin. A comparison of the derived glutelin primary sequences showed that mutations were clustered in three peptide regions. One peptide region corresponded to the highly rautable hypervariable region of legume peptide region of legume 11S storage proteins, a potential target area for protein modification. Expression studies indicated that glutelin mRNA transcripts are differentially accumulated during endosperm development. Promoterss of Gt2 and Gt3 were functional as they direct transient expression of chloramphenicol acetyltransferase in cultured plant cell.

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Identification of Genes that are Induced after Cadmium Exposure by Suppression Subtractive Hybridization

  • 이미옥
    • 한국환경독성학회:학술대회논문집
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    • 한국환경독성학회 2003년도 춘계학술대회
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    • pp.107-107
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    • 2003
  • The heavy metal cadmium is a xenobiotic toxicant of environmental and occupational concern and it has been classified as a human carcinogen. Inhalation of cadmium has been implicated in the development of emphysema and pulmonary fibrosis, but, the detailed mechanism by which cadmium induces adverse biological effects is not yet known. Therefore, we undertook the investigation of genes that are induced after cadmium exposure to illustrate the mechanism of cadmium toxicity For this purpose, we employed the polymerase chain reaction-based suppression subtractive hybridization technique. We identified 29 different cadmium-inducible genes in human peripheral mononuclear cells, such as macrophage migration inhibitory factor, lysophosphatidic acid acyltransferase-${\alpha}$, enolase-1${\alpha}$, VEGF, Bax, neuron-derived orphan receptor-1, and Nur77, which are known to be associated with inflammation, cell survival, and apoptosis. Induction of these genes by cadmium treatment was further confirmed by semi-quantitative reverse-transcription polymerase chain reaction. Further, we found that these genes were also induced after cadmium exposure in normal human lung fibroblast cell line, WI-38, suggesting potential use of this induction profile to monitor cadmium toxicity in the lung. Next, Nur77, one of cadmium-inducible genes, was further studied since the products of Nur77 are known to be involved in the apoptotic process of lung cells. Following cadmium treatment, Nur77 gene expression was increased at protein-level in A549 cells. Consistently, the reporter containing Nur77 binding sequence was activated by 2.5-fold after exposure to cadmium in reporter gene analysis by transient transfection experiments. When the plasmid encoding dominant negative Nur77 that represses the transcriptional function of wild-type Nur77 was transfected into A549 cells, the expression of Bax was significantly reduced, suggesting that induction of Nur77 was an important process in cadmium-induced apoptosis in the cells. Cadmium induced the expression of Nur77 in vivo, confirming the relevance of the data obtained in viro. Together our results suggest that Nur77 gene expression in exposure to cadmium leads apoptosis of lung cells which may cause pathological changes in lung.

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Calcium Signaling-mediated and Differential Induction of Calmodulin Gene Expression by Stress in Oryza sativa L.

  • Phean-o-pas, Srivilai;Punteeranurak, Pornpimon;Buaboocha, Teerapong
    • BMB Reports
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    • 제38권4호
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    • pp.432-439
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    • 2005
  • $Ca^{2+}$/calmodulin transduction pathways have been implicated in mediating stress response and tolerance in plants. Here, three genes encoding calmodulin (Cam) members of the EF-hand family of $Ca^{2+}$-binding proteins were identified from Oryza sativa L. databases. Complementary DNA for each of the calmodulin genes, OsCam1, OsCam2, and OsCam3 were sequenced. OsCam1 and OsCam2 encode a conventional 148-amino acid calmodulin protein that contains four characteristic $Ca^{2+}$-binding motifs. OsCam3 encode a similar protein with a 38-amino-acid extension containing a putative prenylation site (CVIL) at the carboxyl terminus. RT-PCR showed that each of the genes is expressed in leaves and roots of 2-week old rice seedlings. By RNA gel blot analysis, OsCam1 mRNA levels strongly increased in response to NaCl, mannitol and wounding treatments. In contrast, OsCam2 mRNA levels were relatively unchanged under all conditions investigated. NaCl treatment and wounding also increased the OsCam3 mRNA level, but in a more transient manner. Our results indicate that although the expression of genes encoding different calmodulin isoforms is ubiquitous, they are differentially regulated by various stress signals. In addition, we have demonstrated that the calcium-channel blocker lanthanum chloride inhibited the induction of OsCam1 gene expression by both NaCl and mannitol treatments. These results suggest that osmotic stress induced expression of OsCam1 gene requires the $[Ca^{2+}]_{cyt}$ elevation that is known to occur in response to these stimuli.

Correlation of Oct4 and FGF4 Gene Expression on Peri-implantation Bovine Embryos Reconstructed with Somatic Cell

  • K. S. Chung;Yoon, B. S;S. J. Song;Park, Y. J.;S. B. Hong;Lee, H. T.
    • 한국가축번식학회지
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    • 제26권4호
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    • pp.329-338
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    • 2002
  • This study was carried out to investigate the developmental rates of embryo reconstructed with different cell type and to estimate correlation of transcriptional level of octamer-binding transcription factor 4 (Oct4) and fibroblast growth factor 4 (FCF4) gene on peri-implantation stage embryos. Donor cells were transferred into perivitelline space of enucleated oocytes. The karyoplast-cytoplast couplets were accom- plished by cell to cell fusion and activated with ionomycin and 6-dimethylaminopurine. Reconstructed embryos were co-cultured with bovine oviduct epithelial cells in CR 1 aa medium. There is no difference in blastocyst formation rate following nuclear transfer UT) with fetal fibroblast cell (16/50; 32.0%), cumulus cell (16/49; 32.6%) and ear cell (17/52; 32.6%). The expression level of Oct4 and FCF4 in peri-implantation bovine embryo derived from in vitro fertilization (IVF) and NT were determined by reverse-transcription polymerase chain reaction (RT-PCR) technique. In peri-implantation of IVF result in a transient increased of FCF4 paralleled by an increased expression of Oct4. However, Oct4 gene was highly expressed in hatching blastocysts derived from NT compared to IVF. Also, FGF4 expression level in hatching blastocysts and outgrowth stage derived from NT was lower than that of IVF. In conclusion, it is suggested that the different transcription patterns observed in nuclear transfer embryos may lead to a lower rate of embryo development, implantation and pregnancy.

Two Synthetic Ligands for Peroxisome Proliferator- Activated Receptor $\gamma$

  • Kim, Min-A;Jeong, Sun-Hyo;Song, Yang-Heon;Kim, Dae-Il;Yoon, Mi-Chung
    • 대한의생명과학회지
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    • 제10권2호
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    • pp.137-142
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    • 2004
  • The peroxisome proliferator-activated receptor $\gamma$ (PPAR${\gamma}$) is the molecular target for a class of drugs, the antidiabetic thiazolidnediones (TZDs). The heterodimer of PPAR${\gamma}$ with retinoid X receptor (RXR) plays a central role in the regulation of adipogenesis and insulin sensitization. We synthesized two chemicals, DANA87 and DANA88, sharing structural characteristics with TZDs. Given this structural similarity, it was hypothesized that DANA87 and DANA88 may act as PPAR$\gamma$ ligands. In transient transfection assays, DANA87 and DANA88 caused slight increases in the endogenous expression of a luciferase reporter gene containing the PPAR responsive element in 3T3-L1 preadipocytes. However, DANA87 and DANA88 significantly inhibited troglitazone-induced reporter gene activation when cells were treated with a combination of DANA87 or DANA 88 and troglitazone, one of the TZDs that activate PPAR$\gamma$. These results suggest that DANA87 and DANA88 are not only weak agonists of PPAR${\gamma}$ transactivation, but also competitively antagonize troglitazone-induced PPAR$\gamma$ reporter activity.

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