• Title, Summary, Keyword: HMG-1

Search Result 206, Processing Time 0.032 seconds

Characterization and Induction of Potato HMGR genes in Relation to Antimicrobial Isoprenoid Synthesis

  • Park, Doil;Richard M. Bostock
    • Proceedings of the Korean Society of Plant Pathology Conference
    • /
    • /
    • pp.55-75
    • /
    • 1995
  • Induction of HMG-Co A reductase (HMGR) is essential for the biosynthesis of sesquiterpenoid phytoalexins and steroid derivatives in Solanaceous plants following wounding and pathogen infection. To better understand this complex step in stress-responsive isoprenoid synthesis, three classes of cDNAs for HMGR (hmg1, hmg2, and hmg3) were isolated from a potato tuber library. The potato cDNAs had extensive homology in open reading frames but had low homology in the 3'-untranslated regions. RNA gel blot analysis using gene-specific probes revealed that hmg1 is induced by wounding but wound induction is strongly suppressed by arachidonic acid or by inoculation with Phytophthora infestants. In contrast, hmg2 and hmg3 are slightly induced by wounding and strongly enhanced by arachidonic acid or inoculation. The induction and suppression of HMGR genes parallel the suppression of steroid and stimulation of sesquiterpenoid accumulations observed in earlier investigations. Treatment of the tuber disks with a low concentration of methyl-jasmonate doubled the wound induced accumulation of hmg1 transcripts and steroid-glycoalkaloid accumulation, but did not affect the abundance of transcripts for hmg2 or hmg3 nor induce phytoalexins. High concentration of methyl-jasmonate suppressed hmg1 mRNA and steroid-glycoalkaloid accumulation, induced hmg3 mRNA, and did not elicit phytoalexins. Lipoxygenase inhibitors suppressed the accumulation of of hmg1 transcripts and steroid-glycoalkaloids, which were restored by exogeneous methyl-jasmonate. Methyl-jasmonate applied together with arachidonic acid enhanced the elicitor induced accumulation of sesquiterpenes and sustained steroid-glycoalkaloid levels with transcript levels for the various HMGR mRNAs equal to or greater than wound-only treatment. These results domonstrate that the consequences of wound- and pathogen-responses of plants are different at the levels of gene expression and associated secondary metabolism.

  • PDF

Regulation of HMG-CoA Reductase mRNA Stability by 25-hydroxycholesterol

  • Park, Jae-Won;Oh, Seung-Min
    • Preventive Nutrition and Food Science
    • /
    • v.5 no.4
    • /
    • pp.184-188
    • /
    • 2000
  • HMG-CoA reductase is th rate-limiting enzyme of cholesterol biosynthesis. As intracellular levels of cholesterol should be regulated elaborately in response to external stimuli an internal needs, the expression of the HMG-CoA reductase gene is regulated intricately at several different levels from transcription to post-translational modification. In this study, we investigated the regulatory mechanism of HMG-CoA reductase gene expression at the post-transcriptional/pre-translational levels in a baby hamster kidney cell line, C100. when 25-hydroxycholesterol was added to cells cultured in medium containing 5% delipidized fetal bovine serum and 25$\mu$M lovastatin, the levels of HMG-CoA reductase mRNA decreased rapidly, which seemed to be due to the increased degradation of reductase mRNA. These suppressive effects of 25-hydroxycholesterol on MG-CoA reductase mRNA levels were blocked by a translation inhibitor, cycloheximide. Similarly, actinomycin D and 5,6-dichloro-1-$\beta$-D-ribofuranosylbenzimidazole, transcription inhibitors, blocked the 25-hydroxycholesterol-mediated degradation of HMG-CoA reductase mRNA. These results indicate that new protein/RNA synthesis is required for the degradation of HMG-CoA reductase mRNA. In addition, data from the transfection experiments shows that cis-acting determinants, regulating the stability of reductase mRNA, were scattered in the sequence corresponding to 1766-4313 based on the sequence of Syrian hamster HMG-CoA reductase cDNA. Our data suggests that sterol-mediated destabilization of reductase mRNA might be one of the important regulatory mechanism of HMG-CoA reductase gene expression.

  • PDF

Implementation of Very Large Hangul Text Retrieval Engine HMG (대용량 한글 텍스트 검색 엔진 HMG의 구현)

  • 박미란;나연묵
    • Journal of Korea Multimedia Society
    • /
    • v.1 no.2
    • /
    • pp.162-172
    • /
    • 1998
  • In this paper, we implement a gigabyte Hangul text retrieval engine HMG(Hangul MG) which is based on the English text retrieval engine MG(Managing Gigabytes) and the Hangul lexical analyzer HAM(Hangul Analysis Module). To support Hangul information, we use the KSC 5601 code in the database construction and query processing stages. The lexical analyzer, parser, and index construction module of the MG system are modified to support Hangul information. To show the usefulness of HMG system, we implemented a NOD(Novel On Demand) system supporting the retrieval of Hangul novels on the WWW. The proposed system HMG can be utilized in the construction of massive full-text information retrieval systems supporting Hangul.

  • PDF

Characterization and Purification of a Microsomal 3-Hydroxy-3-Methylglutaryl-CoA Reductase in Rice Seedling (벼 HMG-CoA 환원효소의 특성연구)

  • Kim, Jai-Hyun;Paik, Young-Ki;Kim, Jong-Bum;Kim, Jong-Guk;Hwang, Young-Soo;Ha, Sun-Hwa
    • Applied Biological Chemistry
    • /
    • v.41 no.1
    • /
    • pp.47-52
    • /
    • 1998
  • 3-Hydroxy-3-methylglutaryl-CoA reductase (HMGR) catalyzes the conversion of HMG-CoA to mevalonic acid, the first intermediate of isoprenoid biosynthetic pathway in plants. The enzyme was solubilized with 0.4% Brij (polyoxyethylene ether) W-1 from a microsomal fraction of etiolated rice seedlings (Oryza sativa L.) in which its maximal activity was observed on the fourth day after germination. HMGR was purified to near homogeneity by employing $(NH_4)_2SO_4$ fractionation plus chromatographic procedures including DEAE-Sephadex A-50 and HMG-CoA-hexane-agarose affinity column. The size of the purified enzyme was estimated to be 55 kDa when judged by SDS-PAGE analysis with silver staining method. The apparent $K_m$ and $V_{max}$ values for HMG-CoA were determined to be $180\;{\mu}M$ and 107 pmol/min/mg, and those for NADPH were $810\;{\mu}M$ and 32.1 pmol/min/mg, respectively.

  • PDF

Effects of Dietary Garlic Supplementation on Performance and HMG-CoA Reductase in Broiler Chicks (육계사료내 마늘의 첨가가 육계의 생산성과 HMG-CoA Reductase에 미치는 영향)

  • ;;;;S. OHTANI, K. TANAKA
    • Korean Journal of Poultry Science
    • /
    • v.23 no.3
    • /
    • pp.129-134
    • /
    • 1996
  • his study was conducted to determine the effect of dietary garlic supplementation on the growing performance and activity of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase in broiler chicks from 3 to 5 wk post hatching. Fifty chicks were divided into 5 groups with 10 replicates per treatment and placed in a wire battery cage. Five levels of dietary garlic(0, 0.1, 0.3, 0.6 and 1.0%) were provided in an one way analysis. Feed and water were given ad libitum. Feed intake, weight gain and feed conversion rate(FCR) were not affected by the garlic supplementations. The HMG-CoA reductase activity decreased significantly(P<0.05) with the supplementation of garlic powder, compared to the garlic free group. As the dietary garlic level was increased, chicks showed decreased lipid contents in liver and blood serum. The results of this study indicate that blood cholesterol of chicks fed garlic supplemented diet might be reduced by inhibition of RMG-CoA reductase activity.

  • PDF

Serum ${\beta}$-endorphin during Human Menopausal Gonadotropin-Hyperstimulated Menstrual Cycles (Human Menopausal Gonadotropin으로 과배란유도된 월경주기에서의 혈청 ${\beta}$-endorphin에 과한 연구)

  • Kim, Jung-Gu;Mun, Shin-Yong;Chang, Yoon-Seok;Lee, Jin-Yong
    • Clinical and Experimental Reproductive Medicine
    • /
    • v.17 no.2
    • /
    • pp.159-165
    • /
    • 1990
  • It has been reported that endogenous opioid peptides play a role in the control of the reproductive function. The goal of this study was to evaluate changs in the serum levels of ${\beta}$-endorphin during hyperstimulated menstrual cycle and their relationship to serum prolactin levels. Serum ${\beta}$-endorphin and prolactin levels were measured during menstrual cycles of 10 normal cylic women hyperstimulated by human menopausal gonadotropin (HMG) and of 10 women by clomiphene/HMG among in vitro fertilization candidates. The results were summarized as follows. 1. In clomiphene/HMG hyperstimulated menstrual cycle the mean serum ${\beta}$-endorphin level insignificantly on 2 day before aspiration of oocyte compared to basal level and reached maximum level on 1 day after aspiration. 2. There was a significant peak of the mean serum ${\beta}$-endorphin level on 1 day before aspiration in HMG hyperstimulated menstrual cycle. 3. On the same day from aspiration, there was no significant differences in the mean serum ${\beta}$-endorphin levels between HMG and clomiphene/HMG hyperstimulated cycles. 4. No significant correlation was noted between serum ${\beta}$-endorphin levels and prolactin levels.

  • PDF

Screening of Phenolic Compounds with Inhibitory Activities against HMG-CoA Reductase (페놀 화합물로부터 HMG-CoA reductase 저해 활성 물질 탐색)

  • Son, Kun Ho;Lee, Ju Yeon;Lee, Jeong Soon;Kang, Sam Sik;Sohn, Ho Yong;Kwon, Chong Suk
    • Journal of Life Science
    • /
    • v.27 no.3
    • /
    • pp.325-333
    • /
    • 2017
  • High level of plasma cholesterol is strongly associated with the development of atherosclerosis and coronary heart disease. Clinical trials designed to reduce plasma cholesterol level by diet or pharmacological intervention have resulted in marked reduction of disease incidence. The enzyme 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase which reduces cholesterol biosynthesis in the liver is the key enzyme of the mevalonate pathway that produces cholesterol. In this study, 71 naturally occurring phenolic compounds were tested for inhibitory activities against HMG-CoA reductase. Eleven compounds out of 71 showed inhibitory activities: three hydrolyzable tannin (geraniin, acetonyl geraniin and pentagalloyl ${\beta}-D-glucose$), four benzoic acid derivatives (benzoic acid, trans-cinnamic acid, 2,4-dihydroxybenzoic acid and 2,5-dihydroxybenzoic acid), and four naphthoquinone derivatives (1,2-naphthoquinone, 1,4-naphthoquinone, plumbagin and shikonin). At the concentration of $10{\mu}g/ml$, 1,4-naphthoquinone inhibited HMG-CoA reductase by 99.4%, and then plumbagin 91.4%, pentagalloyl ${\beta}-D-glucose$ 46.6%, 2,4-dihydroxybenzoic acid 40.9%, shikonin 37.7%, 1,2-naphthoquinone 36.6%, trans-cinnamic acid 32.0%, acetonyl geraniin 30.2%, benzoic acid 28.5%, geraniin 28.3% and 2,5-dihydroxybenzoic acid 22.3%, respectively. $IC_{50}$ values of 1,4-naphthoquinone and plumbagin was $2.1{\mu}g/ml$ and $5.8{\mu}g/ml$, respectively.

THE EFFECT OF DIETARY FATS ON THE HEPATIC AND INTESTINAL 3-HYDROXY-3-METHYLGLUTARYL COENZYME A REDUCTASE ACTIVITIES IN CHICKS

  • Youn, B.S.;Tananka, K.;Ohtani, S.;Santoso, U.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.6 no.2
    • /
    • pp.281-290
    • /
    • 1993
  • This experiment was designed to evaluate the effect of degree of unsaturation (Experiment 1) and the chain length of constituent fatty acids of dietary fats (Experiment 2) on-3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activities in the liver and small intestine of chicks. Chicks were fed experimental diets for 10 days and then killed for the determination of the HMG-CoA reductase activities in the intestinal epithelial cell and hepatic microsomes. The hepatic HMG-CoA reductase activity showed the highest value in chicks fed the tallow-containing diet. Chicks fed diets containing safflower or coconut oil resulted in a significantly lower intestinal HMG-CoA reductase activity in comparison with those fed the olive oil-containing diet. The hepatic HMG-CoA reductase activity was significantly higher when fat-free and trilaurin were fed than when any other triglycerides were fed. This activity showed the lowest value in the chicks fed the diet containing tristearin. The HMG-CoA reductase activities in the jejunum and ileum were significantly or tended to be higher when trilaurin was fed than when any other triglycerides were fed. Except when trilaurin was fed, the presence of saturated fat in the diet did not have a significant effect on the intestinal HMG-CoA reductase activity, unlike the effect shown when a highly unsaturated fat was added to the diet. There was no significant correlation between the HMG-CoA reductase activities of the liver and intestinal, and the HMG-CoA reductase activity and cholesterol content of the intestinal epithelial cells.

A Comparative Analysis of Blood Estradiol-17${\beta}$ Levels According to Varying Regimens of $Clomid^{(R)}$(Clomiphene citrate) Administration in Induced Ovulated Menstrual Cycles ($Clomid^{(R)}$(Clomiphene citrate)의 투여시기와 용량을 변수로 한 혈중 $Estradiol-17{\beta}$의 동태에 관한 연구)

  • Chang, H.J.;Suh, B.H.;Lee, J.H.
    • Clinical and Experimental Reproductive Medicine
    • /
    • v.15 no.1
    • /
    • pp.40-52
    • /
    • 1988
  • Estradiol-17${\beta}$($E_2$) levels in the blood were estimated according to varying the time and amount of the administration of $Clomid^{(R)}$. $Clomid^{(R)}$ were administered on the 2nd, 3rd and 4th menstrual day corresponding to the recruitment period and on the 5th menstrual day corresponding to the selection period of the ovarian follicles, respectively. And $Clomid^{(R)}$ were administered 50 mg, 100 mg and 150 mg/day, repectively. The effects of the sequential HMG to $E_2$ levels in the blood were also estimated. The results were as following : 1. Blood $E_2$ levels according to the day and amount of administration of $Clomid^{(R)}$ were the highest in the group 3(D $2{\sim}6$, 150 mg/day, with HMG) and the lowest in the group 6(D $5{\sim]9$, 50 mg/day, without HMG). $E_2$ levels showed increasing tendency to 0 day. 2. In the cases of the administration of $Clomid^{(R)}$ during the $2nd{\sim}6th$ menstrual day, $E_2$ levels according to the amount were similar among groups and showed increasing tendency daily. 3. In the cases of administration of $Clomid^{(R)}$ during the $2nd{\sim}6th$ menstrual day, $E_2$ levels according to the sequential HMG independent of the amount of $Clomid^{(R)}$ were higher in the with HMG group than without HMG groups. 4. In the case of the administration of $Clomid^{(R)}$ during the $5th{\sim}9th$ menstrual day, $E_2$ levels according to the amount were the highest in the 100 mg/day group and the lowest in the 50mg/day group. 5. In the cases of administration of $Clomid^{(R)}$ independent of the amount during the 5th${\sim}$9th menstrual day, $E_2$ levels according to the sequential HMG were higher in the with HMG group than without HMG group. 6. $E_2$ levels according to the amount independent of the day of the administration of $Clomid^{(R)}$ were the highest in the 100 mg/day group and 150 mg/day, 50 mg/day group in low sequence. 7. $E_2$ levels according to the sequential HMG independent of the day and amount of the administration of $Clomid^{(R)}$ were higher in the with HMG group than the without HMG group. 8. $E_2$ levels according to the day of the administration of $Clomid^{(R)}$ independent of the amount of $Clomid^{(R)}$ and sequential HMG were the highest in the group D 2${\sim}$6 and the lowest in the group D 5${\sim}$9. According to the above results, there were higher $E_2$ levels in the group with sequential HMG than without HMG. Therefore, the hypothesis, postulated initially by the author, was not verified that sequential HMG would not affect the $E_2$ levels which were related to the process of the selection of the ovarian follicle in the connection with 'FSH window'. Because it may be the stimulation after the selection of later predominant follicle. And the highest level of $E_2$ was estimated in the $Clomid^{(R)}$ 150 mg/day group with sequential HMG on the 2nd${\sim}$6th day, and the higher levels were estimated in the 2nd${\sim}$6th day, 3rd${\sim}$7th day and 4th${\sim}$8th day groups than the 5th${\sim}$9th day group. The lower levels were estimated in the $Clomid^{(R)}$ 50 mg/day group without HMG than 100 mg/day and 150 mg/day on the 5th${\sim}$9th day. Therefore, further study will be needed that combines analyses of the E2 levels in the blood according to the various administration of $Clomid^{(R)}$ with or without sequential HMG and determination of the numbers and size of the ovarian follicles by ultrasonogram.

  • PDF