• Title/Summary/Keyword: Hormonal regulation

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Hormonal Regulation of Acetyl-CoA Carboxylase Promoter I Activity in Rat Primary Hepatocytes (흰쥐의 간세포에서 호르몬에 의한 Acetyl-CoA Carboxylase Promoter I Activity 조절에 대한 연구)

  • 이막순;양정례;김윤정;김영화;김양하
    • Journal of Nutrition and Health
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    • v.35 no.2
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    • pp.207-212
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    • 2002
  • Acetyl-CoA carboxylase (ACC) is the enzyme that controls no devo fatty acid biogynthesis, and this enzyme catalyzes the carboxylation pathway of acetyl-CoA to malonyl-CoA. Acetyl-CoA carboxylase gene expression was regulated by nutritional and hormonal status. The present study was performed to identify the regulation mechanism of ACC gene promoter I. The fragments of ACC promoter I -1.2-kb region wert recombined to pGL3-Basic vector with luciferase as a reporter gene. The primary hepatocytes from the rat were used to investigate the hormonal regulation of ACC promoter I activity. ACC PI (-1.2)/Luc plasmid was trtransferred into primary hepatocytes using lipofectin. Activity of luciferase was increased two-fold by 10-9M, three-fold by 10-8M, 10-6M, 3.5-fold by 10-6M, and 4.5-fold by 10-7M insulin treatment, respectively. In the presence of dexamethasone (1 $\mu$M), the effects of insulin increased about 1.5-fold, showing the additional effects of dexamethasone. Moreover, the activity of luciferase increased with insulin+dexamethasone, insulin+T3, dexamethasone+T3, and dexamethasone+insulin+T3 treatment approximately 6-, 4-, 6.5-, and 10-fold, respectively. Therefore it can be postulated that 1) these hormones coordinately regulate acetyl-CoA caroxylase gene expression via regulation of promoter activity, 2) the -1.2-kb region of ACC promoter I may have the response element sequences for insulin, dexamethasone, and T3.

Cloning, Expression and Hormonal Regulation of Steroidogenic Acute Regulatory Protein Gene in Buffalo Ovary

  • Malhotra, Nupur;Singh, Dheer;Sharma, M.K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.20 no.2
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    • pp.184-193
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    • 2007
  • In mammalian ovary, steroidogenic acute regulatory (StAR) protein mediates the true rate-limiting step of transport of cholesterol from outer to inner mitochondrial membrane. Appropriate expression of StAR gene represents an indispensable component of steroidogenesis and its regulation has been found to be species specific. However, limited information is available regarding StAR gene expression during estrous cycle in buffalo ovary. In the present study, expression, localization and hormonal regulation of StAR mRNA were analyzed by semi-quantitative RT-PCR in buffalo ovary and partial cDNA was cloned. Total RNA was isolated from whole follicles of different sizes, granulosa cells from different size follicles and postovulatory structures like corpus luteum and Corpus albicans. Semi-quantitative RT-PCR analyses showed StAR mRNA expression in the postovulatory structure, corpus luteum. No StAR mRNA was detected in total RNA isolated from whole follicles of different size including the preovulatory follicle (>9 mm in diameter). However, granulosa cells isolated from preovulatory follicles showed the moderate expression of StAR mRNA. To assess the hormonal regulation of StAR mRNA, primary culture of buffalo granulosa cells were treated with FSH (100 ng/ml) alone or along with IGF-I (100 ng/ml) for 12 to 18 h. The abundance of StAR mRNA increased in cells treated with FSH alone or FSH with IGF-I. However, effect of FSH with IGF-I on mRNA expression was found highly significant (p<0.01). In conclusion, differential expression of StAR messages was observed during estrous cycle in buffalo ovary. Also, there was a synergistic action of IGF-I on FSH stimulation of StAR gene.

PIF4 Integrates Multiple Environmental and Hormonal Signals for Plant Growth Regulation in Arabidopsis

  • Choi, Hyunmo;Oh, Eunkyoo
    • Molecules and Cells
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    • v.39 no.8
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    • pp.587-593
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    • 2016
  • As sessile organisms, plants must be able to adapt to the environment. Plants respond to the environment by adjusting their growth and development, which is mediated by sophisticated signaling networks that integrate multiple environmental and endogenous signals. Recently, increasing evidence has shown that a bHLH transcription factor PIF4 plays a major role in the multiple signal integration for plant growth regulation. PIF4 is a positive regulator in cell elongation and its activity is regulated by various environmental signals, including light and temperature, and hormonal signals, including auxin, gibberellic acid and brassinosteroid, both transcriptionally and post-translationally. Moreover, recent studies have shown that the circadian clock and metabolic status regulate endogenous PIF4 level. The PIF4 transcription factor cooperatively regulates the target genes involved in cell elongation with hormone-regulated transcription factors. Therefore, PIF4 is a key integrator of multiple signaling pathways, which optimizes growth in the environment. This review will discuss our current understanding of the PIF4-mediated signaling networks that control plant growth.

Hormonal Regulation of Glycerol-Phosphate Acyltransferase Gene Expression (Glycerol-Phosphate Acyltransferase Gene Expression의 호르몬에 의한 조절)

  • 손승렬;신동훈
    • Microbiology and Biotechnology Letters
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    • v.21 no.5
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    • pp.473-477
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    • 1993
  • Both glycerol-phosphate acyltransferase (GPAT) and 7.2 kb mRNAs were present at the highest level in liver. Glycerol-phosphate acyltransferase and 7.2 kb mRNA levels increased dramatically when fasted mice were refed a high carbohydrate diet. In mature 3T3-L1 adipocytes, insulin increased both glycerol-phosphate acyltransferase and 7.2kb mRNA levels 2.6 to 3-fold while dibutyryl cAMP decreased mRNA levels by 50% and 80%, respectively. These results indicate positive regulation by insulin and negative regulation by dibutyryl cAMP of both glycerol-phosphate acyltransferase and 7.2 kb mRNA.

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Molecular Characterization of a Bombyx mori Protein Disulfide Isomerase(bPDI) (누에 배양세포로부터 분리한 Protein Disulfide Isomerase 유전자의 발현 특성)

  • 구태원;윤은영;황재삼;강석우;권오유
    • Journal of Life Science
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    • v.11 no.5
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    • pp.415-422
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    • 2001
  • Many secreted proteins have disulfide bonds that are important for their structure and function. Protein disulfide isomerase (PDI, EC 5.3.1.4.), an enzyme that catalyzes the formation and rearrangement of thiol/disulfide exchange reactions, is a resident of the endoplasmic reticulum (ER). The subcellular localization and its function as catalyst of disulfide bond formation in the biosynthesis of secretory and cell membrane proteins suggest that PDI plays a key role in the secretory pathway. We have isolated a cDNA encoding protein disulfide isomerase from Bombyx mori(bPDI). It has been characterized under ER stress conditions (dominantly induced by calcium ionophore A23187, tunicamycin and DTT), which is known to cause an accumulation of unfolded proteins in the ER. Furthermore, It has also been examined for tissue distribution(pronounced at the fat body), hormonal regulation (juvenile hormone, insulin and juvenile +transferrin; however, it is not effected by transferrin alone), and the effect of exogenous bacteria (peak at 16 h after infection) on the bPDI mRNA expression. The results suggest that bPDI is a member of the ER stress protein group, and it may play an important role in exogenous bacterial infection in fat body, and that homones regulate its expression.

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Hormonal Regulation of Leptin, Resistin, and Plasminogen Activator Inhibitor-1 Gene Expression in 3T3-L1 Adipocytes

  • Lee, Hyun-Jung;Kim, Yang-Ha
    • Preventive Nutrition and Food Science
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    • v.9 no.4
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    • pp.336-341
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    • 2004
  • Leptin, resisitn and PAI-1 (plasminogen activator inhibitor-1) are synthesized and secreted by rodent fat cells and recently postulated to be an important link to obesity. This study was conducted to characterize the hormonal regulation of leptin, resistin, and PAI-1 gene expression in the 3T3-L1 adipocytes. The cells were treated with 0.5 $\mu$M insulin, 1 $\mu$M dexamethasone (Dex), or 0.05 $\mu$M triiodothyronine (T3) for 72 hours. The mRNA levels of each peptide were measured by semi-quantitative RT-PCR. The mRNA level of the leptin-producing ob gene was significantly increased by insulin, Dex, and T3 by 3.2-, 3.1- and 2.7-fold, respectively, compared to the control (p < 0.05). The level of resistin mRNA was increased by insulin, Dex, and T3 by 2.7-, 2.5- and 2-fold, respectively, compared to the control (p < 0.05). Likewise, the level of PAI-1 mRNA was significantly increased by insulin, Dex, and T3 compared to the control (p < 0.05). Taken together, our results suggest that insulin, Dex, and T3 may regulate the gene expression of leptin, resistin, and PAI-1 in 3T3-L1 adipocytes.

In vitro Studies on Hormonal Regulation of Vitellogenin Synthesis in Tilapia Hepatocytes

  • Kim, Byung-Ho;Akihiro Takemura;Lee, Young-Don
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2002.10a
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    • pp.216-217
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    • 2002
  • Vitellogenin (VTG) is a Precursor form of egg yolk Proteins, which appear only in the blood circulation of female fish and its synthesis in the liver is considered to be regulated by several hormones. It has been reported that in addition to estradiol-17 $\beta$ (E2) several hormones are also involved in the production site of VTG, the liver (Peyon et al., 1996; Mori et al., 1998). (omitted)

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