• Journal of Applied Biological Chemistry
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• v.50 no.2
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• pp.97-100
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• 2007

• Animal cells and systems
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• v.2 no.3
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• pp.341-349
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• 1998

To analyze the effects of surfactants on the biosynthesis of galactolipid and the composition of fatty acids, the chloroplast envelope and thylakoid membrane were cultivated in medium treated with anionic surfactants, such as linear alkylbenzene sulfonate (0.002%, LAS), a-olefin sulfonate (O.01%, AOS), and sodium lauryl ether sulfate (0.08%, SLES), respectively. During the cultivation, the chloroplast envelope and thylakoid membrane were isolated from the cells collected at the early and middle phase of the culture and the contents of their fatty acid composition were compared with the control. When treated with surfactants, the contents of total lipid MDGD methylesters, and DGDG methylesters decreased significantly when compared with the control. It was also confirmed that more unsaturated fatty acids were involved in the biosynthesis of galactolipid. The fatty acids utilized in the biosynthesis of MGDG were in the chloroplast envelope and in the control, and linoleic acid in LAS, linolenic acid and oleic acid in AOS, and linolenic acid and oleic acid in SLES. The fatty acids in the biosynthesis of DGDG were linolenic acid and oleic acid in the control linolenic acid and stearic acid in LAS, oleic acid and linolenic acid in AOS, oleic acid and linolenic acid in SLES. In the thylakoid membrane, the major fatty acids in the biosynthesis of MGDG were linolenic acid and oleic acid in the control, oleic acid and linolenic acid in LAS, linolenic acid and linoleic acid in AOS, linolenic acid and palmitoleic acid in SLES. The fatty acids in the biosynthesis of DGDG were linolenic acid and oleic acid in the control, oleic acid and linolenic acid in LAS, linolenic acid and linoleic acid in AOS, palmitoleic acid and oleic acid in SLES.

• Journal of Microbiology and Biotechnology
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• v.30 no.12
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• pp.1835-1842
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• 2020

Ergosterol, an essential constituent of membrane lipids of yeast, is distributed in both the cell membrane and intracellular endomembrane components such as vacuoles. Honokiol, a major polyphenol isolated from Magnolia officinalis, has been shown to inhibit the growth of Candida albicans. Here, we assessed the effect of honokiol on ergosterol biosynthesis and vacuole function in C. albicans. Honokiol could decrease the ergosterol content and upregulate the expression of genes related with the ergosterol biosynthesis pathway. The exogenous supply of ergosterol attenuated the toxicity of honokiol against C. albicans. Honokiol treatment could induce cytosolic acidification by blocking the activity of the plasma membrane Pma1p H+-ATPase. Furthermore, honokiol caused abnormalities in vacuole morphology and function. Concomitant ergosterol feeding to some extent restored the vacuolar morphology and the function of acidification in cells treated by honokiol. Honokiol also disrupted the intracellular calcium homeostasis. Amiodarone attenuated the antifungal effects of honokiol against C. albicans, probably due to the activation of the calcineurin signaling pathway which is involved in honokiol tolerance. In conclusion, this study demonstrated that honokiol could inhibit ergosterol biosynthesis and decrease Pma 1p H+-ATPase activity, which resulted in the abnormal pH in vacuole and cytosol.

• Korean journal of applied entomology
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• v.61 no.1
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• pp.29-34
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• 2022

Pheromone biosynthesis in the pheromone gland is triggered from release of pheromone biosynthesis-activating neuropeptide (PBAN) synthesized in the suboesophageal ganglion. PBAN binds to its receptor on the epithelial cell membrane and activates signal transduction pathways for the pheromone biosynthesis. This study reviews sex pheromone, PBAN and its receptor, and pheromone biosynthesis pathway of Maruca vitrata.

• Journal of Microbiology and Biotechnology
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• v.14 no.3
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• pp.635-638
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• 2004

An ATP-binding-cassette (ABC) transporter gene in the cephabacin biosynthetic gene cluster of Lysobacter lactamgenus was characterized. The amplified orf10 (cpbJ) gene was subcloned into pET-28a(+) vector and expressed in E. coli BL21(DE3) strain by 0.5 mM IPTG at $30^{\circ}C$. The membrane fraction of recombinant E. coli cells was separated by ultracentrifugation, and solubilized using 2.5% octyl-$\beta$-D-glucoside. Using the solubilized membrane fraction, the artificial proteoliposomes were reconstituted and analyzed for the biological activity of CpbJ protein. Upon measuring ATPase activity, the proteoliposome made from recombinant E. coli membrane proteins showed slightly higher activity than that from host E. coli membrane proteins. In the measurement of membrane transport activity, the reconstituted proteoliposome of recombinant E. coli membrane proteins exhibited higher activity when both substrates of cephalosporin C and L-Ala-L-Ser were applied, compared to the case of cephalosporin C or L-Ala-L-Ser only. It implies that the CpbJ protein is an ABC transporter secreting cephabacin antibiotics synthesized in cytoplasm.

• Korean Journal of Weed Science
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• v.14 no.1
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• pp.1-7
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• 1994

The effects of S-23142{N-(4-chloro-2-fluoro-5-propargyloxyphenyl)-3, 4, 5, 6-tetrahydrophtalimide}, on protoporphyrin IX(PPIX) biosynthesis in Spinacia oleracea L, leaf in vivo and in vitro condition were investigated by reversed-phase HPLC with fluorescence detector. The stroma and the membrane fraction of spinach chloroplast were isolated by osmotic regulation. The conversion of ${\delta}$-aminolevulinic acid(ALA) to PPIX occured more in the stroma than in the membrane fraction. It suggested that the enzymes that catalyse PPIX biosynthesis from ALA were localized in the stroma. Also, the synthesized PPIX content from ALA was completely inhibited by $10^{-8}M$ of S-23412 or $10^{-7}M$ of acifluorfen in the stroma but not in the membrane fractions. Therefore, these results suggested that the target site of S-23142 and acifluorfen may exist in the stroma fraction of spinach chloroplast.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.2
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• pp.109-114
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• 2005

Ion fluxes across the plasma membrane activated by 1 mM $Ce^{4+}$, cell apoptosis and taxol biosynthesis in suspension cultures of Taxus cusp/data were studied. The extracellular pH sharply decreased upon the addition of 1 mM $Ce^{4+}$, then increased gradually and exceeded the initial pH value over a time period of 12 h. The extracellular $Ca^{2+}$ concentration decreased within the first 3 h after the addition of $Ce^{4+}$, then gradually decreased to one third of initial value in control at about 72 h and remained unchanged afterwards. Experiments with an ion channel blocker and a $Ca^{2+}$-channel blocker indicated that the dynamic changes in extracellular pH and the $Ca^{2+}$ concentration resulted from the $Ce^{4+}$-induced activation of W uptake and $Ca^{2+}$ influx across the plasma membrane via ion channels. A pretreatment of the ion channel blocker initiated $Ce^{4+}$-treated cells to undergo necrosis, and the prior addition of the $Ca^{2+}$-channel blocker inhibited $Ce^{4+}$-induced taxol biosynthesis and apoptosis. It is thus inferred that W uptake is necessary for cells to survive a $Ce^{4+}$-caused acidic environment and is one of the mechanisms of $Ce^{4+}$-induced apoptosis. Furthermore, the $Ca^{2+}$ influx across the plasma membrane mediated both the $Ce^{4+}$-induced apoptosis and taxol biosynthesis.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.160.1-160.1
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• 2003

In order to confirm the biological function of ORF10 in cephabacin biosynthesis gene cluster of Lysobacter lactamgenus as an ATP-binding-cassette (ABC) transporter, the gene for ORF10 was amplified and subcloned into pET-28a(+) expression vector. After gene induction with 0.5 mM IPTG at 30~! and further cultivation at $30^~$ !. for 8 hr, a lot of the recombinant ORF10 protein was produced as soluble form in cytoplasmic fraction as well as a membrane protein in the membrane fraction as likely as other ABC transporters. (omitted)

• Mycobiology
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• v.38 no.3
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• pp.215-218
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• 2010

Azoles are currently the most widely used class of antifungal drugs clinically, and are effective for treating fungal infections. Target site of azoles is ergosterol biosynthesis in fungal cell membrane, which is absent in the mammalian host. However, the development of resistance to azole treatments in the fungal pathogen has become a significant challenge. Here, we report the identification and functional characterization of a UPC2 homolog in the human pathogen Cryptococcus neoformans. UPC2 plays roles in ergosterol biosynthesis, which is also affected by the availability of iron in Saccharomyces cerevisiae and Candida albicans. C. neoformans mutants lacking UPC2 were constructed, and a number of phenotypic characteristics, including antifungal susceptibility and iron utilization, were analyzed. No differences were found between the mutant phenotypes and wild type, suggesting that the role of C. neoformans UPC2 homolog may be different from those in S. cerevisiae and C. albicans, and that the gene may have a yet unknown function.

• BMB Reports
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• v.38 no.6
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• pp.633-638
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• 2005

Biosynthesis of prostanoids is regulated by three sequential enzymatic steps, namely phospholipase $A_2$ enzymes, cyclooxygenase (COX) enzymes, and various lineage-specific terminal prostanoid synthases. Prostaglandin E synthase (PGES), which isomerizes COX-derived $PGH_2$ specifically to $PGE_2$, occurs in multiple forms with distinct enzymatic properties, expressions, localizations and functions. Two of them are membrane-bound enzymes and have been designated as mPGES-1 and mPGES-2. mPGES-1 is a perinuclear protein that is markedly induced by proinflammatory stimuli, is down-regulated by anti inflammatory glucocorticoids, and is functionally coupled with COX-2 in marked preference to COX-1. Recent gene targeting studies of mPGES-1 have revealed that this enzyme represents a novel target for anti-inflammatory and anti-cancer drugs. mPGES-2 is synthesized as a Golgi membrane-associated protein, and the proteolytic removal of the N-terminal hydrophobic domain leads to the formation of a mature cytosolic enzyme. This enzyme is rather constitutively expressed in various cells and tissues and is functionally coupled with both COX-1 and COX-2. Cytosolic PGES (cPGES) is constitutively expressed in a wide variety of cells and is functionally linked to COX-1 to promote immediate $PGE_2$ production. This review highlights the latest understanding of the expression, regulation and functions of these three PGES enzymes.