• Journal of Microbiology and Biotechnology
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• 제4권4호
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• pp.237-244
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• 1994

The vector systems for the expression and secretion of human lipocortin-l (LC1) from Saccharomyces cerevisiae were constructed with GAL10 promoter and the prepro leader sequence of mating factor-$\alpha$1. They were further constructed to contain three different transcription terminators; GAL7 terminator, LCl terminator and a fused form of these two terminators. The expression and secretion levels of LCl were compared to investigate the effect of transcription terminators on the LCl gene expression. For the expression cassettes employing the GAL7 terminator or the terminator of fused form, the expression levels of LCl were measured by scanning the immunoreactive LCl protein bands, and were found to be 0.27 g/l and 0.32 g/l, respectively. The highest expression level of 0.54 g/l was obtained with the expression vector containing the LCl transcription terminator. In all expression cassettes, the majority of LCl proteins expressed were retained intracellularly, indicating a low secretion efficiency of about 5%. The high expression level of LCl was explained by the great content and stability of LCl mRNA transcribed from the LCl terminator-employing vector. The results of this study demonstrate that the LCl transcription terminator functions for the expression of LCl in S. cerevisiae better than the GAL7 terminator.

• Genomics & Informatics
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• 제5권2호
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• pp.77-82
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• 2007

Serotonin (5-HT), the endogenous nonselective 5-HT receptor agonist, activates the inositol-1,4,5-triphosphate/calcium $(InsP3/Ca^{2+})$ signaling pathway and exerts both stimulatory and inhibitory actions on cAMP production and neuromodulin secretion in rat hypothalamic neurons. Specific mRNA transcripts for 5-HT1A, 5-HT2C and 5-HT4 were identified in rat hypothalamic neurons. These experiments were supported by combined techniques such as cAMP and a $Ca^{2+}$ assays in order to elucidate the associated receptors and signaling pathways. The cAMP production and neuromodulin release were profoundly inhibited during the activation of the Gi-coupled 5-HT1A receptor. Treatment with a selective agonist to activate the Gq-coupled 5-HT2C receptor stimulated InsP3 production and caused $Ca^{2+}$ release from the sarcoplasmic reticulum. Selective activation of the Gs-coupled 5-HT4 receptor also stimulated cAMP production, and caused an increase in neuromodulin secretion. These findings demonstrate the ability of 5-HT receptor subtypes expressed in neurons to induce neuromodulin production. This leads to the activation of single or multiple G-proteins which regulate the $InsP3/Ca^{2+}/PLC-{\gamma}$ and adenyl cyclase / cAMP signaling pathways.

• The Plant Pathology Journal
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• 제36권6호
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• pp.608-617
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• 2020

The type III secretion system (T3SS) is a key virulence determinant in the infection process of Pseudomonas syringae pv. tomato DC3000 (Pst DC3000). Pathogen constructs a type III apparatus to translocate effector proteins into host cells, which have various roles in pathogenesis. 4-Hydroxybenozic acid and vanillic acid were identified from root extract of Sedum middendorffianum to have inhibitory effect on promoter activity of hrpA gene encoding the structural protein of the T3SS apparatus. The phenolic acids at 2.5 mM significantly suppressed the expression of hopP1, hrpA, and hrpL in the hrp/hrc gene cluster without growth retardation of Pst DC3000. Auto-agglutination of Pst DC3000 cells, which is induced by T3SS, was impaired by the treatment of 4-hydroxybenzoic acid and vanillic acid. Additionally, 2.5 mM of each two phenolic acids attenuated disease symptoms including chlorosis surrounding bacterial specks on tomato leaves. Our results suggest that 4-hydroxybenzoic acid and vanillic acid are potential anti-virulence agents suppressing T3SS of Pst DC3000 for the control of bacterial diseases.

• 대한수의학회지
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• 제7권2호
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• pp.51-55
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• 1967

The mammary excretion of suphamethomidine after intravenous and/or oral administration was investigated in cow. The results show that sulphamethomidine is bound to plasma proteins to a great extent (80~90%). Ay a dosage of 60 mg./kg. maximal concenration in plasma of this sulphonamide was reached 7-10 hours after oral dosing. The sulphonamide concentration in plasma slowly declined after both oral and intravenous administration (fig. 1, 2, and 3) The concentration of sulphonamide in milk was very low and the excretion was completed in 7 days after a single oral dose and 5 days after intravenous injection while in the case of blood plasma it was 11 and 7 days, respectively. In addition, the renal excretion of sulphamethomidine was investigated while under continuous intravenous intravenous infusion. The excretion ratios varies according to self depression (table. 1). Blockade of the tubular secretion with diodone lowered the excretion of sulphamethomidine. It is concluded that the renal excretion of sulphamethomidine in cows occurs by filtration by slight tubular secretion and also by a high rate of back diffusion.

• Journal of Microbiology
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• 제43권spc1호
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• pp.85-92
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• 2005

An early step in the pathogenesis of non-typhoidal Salmonella species is the ability to penetrate the intestinal epithelial monolayer. This process of cell invasion requires the production and transport of secreted effector proteins by a type III secretion apparatus encoded in Salmonella pathogenicity island I (SPI-1). The control of invasion involves a number of genetic regulators and environmental stimuli in complex relationships. SPI-1 itself encodes several transcriptional regulators (HilA, HilD, HilC, and InvF) with overlapping sets of target genes. These regulators are, in turn, controlled by both positive and regulators outside SPI-1, including the two-component regulators BarA/SirA and PhoP/Q, and the csr post-transcriptional control system. Additionally, several environmental conditions are known to regulate invasion, including pH, osmolarity, oxygen tension, bile, $Mg^{2+}$ concentration, and short chain fatty acids. This review will discuss the current understanding of invasion control, with emphasis on the interaction of environmental factors with genetic regulators that leads to productive infection.

• 한국동물학회지
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• 제35권3호
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• pp.271-276
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• 1992

20-hydroxvecdysone (20-HE) seems to be related in the regulation of vitellogenesis in Drosophifa sp. (robwta species sroup). Although yolk proteins (YPs) synthesis does not occur at a high rate in fat body cells of one daw-old female after eclosion, application of 20-HE to isolated abdomens deprived of anterior endocrine glands stimulated the synthesis and secretion of YPs into the hemolvmph. An injection of 0.3 $\mul$ of a 10-s M 20-HE was sufficient topromote synthesis and secretion of YPs in isolated abdomens. The response of isolated automens to hormones was first detected between 2 hr and 3 hr after treaDent of 10-s M 20-HE. Transcript analysis showed that the effect of 20-HE on yolk protein synthesis was mediated at the level of transcription.

• Journal of Oral Medicine and Pain
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• 제20권1호
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• pp.7-18
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• 1995

The Purpose of this article is to describe the biochemical properties and biological functions of several salivary proteins that possess the unusual properties of inhibiting spontaneous and secondary precipitation of calcium phosphate. This function is very important since human salivary secretion is supersaturated with respect to calcium phosphate. Biological function of statherin, proline rich protein (PRP) and histidine rich protein (HRP) is to inhibit precipitation of calcium phosphate in salivary glands, in the oral fluids, and onto tooth surfaces. The resulting supersaturated state of the salivary secretions contributes a protective and reparative environment which is important for the integrity of the tooth. Beneficial consequences of salivary supersaturation with respect to calcium phosphate are selectively expressed in the oral cavity- that is, protection is provided for the dental enamel-while undesirable consequences, for example, precipitation of calcium phosphates in the salivary glands and onto the teeth do not occur. Purification and structural characteristics of these proteins as well as clinical significance of functions of each protein will be discussed.

• BMB Reports
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• 제40권6호
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• pp.1058-1068
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• 2007

The post-translational modifications of Ser and Thr residues by O-linked $\beta$-N-acetylglucosamine (O-GlcNAc), i.e., O-GlcNAcylation, is considered a key means of regulating signaling, in a manner analogous to protein phosphorylation. Furthermore, it has been suggested that the increased flux of glucose through the hexosamine biosynthetic pathway (HBP) stimulates O-GlcNAcylation, and that this may be responsible for many of the manifestations of type 2 diabetes mellitus. To determine whether excessive O-GlcNAcylation of target proteins results in pancreatic $\beta$ cell dysfunction, we increased nucleocytoplasmic protein O-GlcNAcylation levels in $\beta$ cells by exposing them to streptozotocin and/or glucosamine. Streptozotocin and glucosamine co-treatment increased O-GlcNAcylated proteomic patterns as assessed by immunoblotting, and these increases in nuclear and cytoplasmic protein O-GlcNAcylations were accompanied by impaired insulin secretion and enhanced apoptosis in pancreatic $\beta$ cells. This observed $\beta$cell dysfunction prompted us to examine Akt and Bcl-2 family member proteins to determine which proteins are O-GlcNAcylated under conditions of high HBP throughput, and how these proteins are associated with $\beta$ cell apoptosis. Eventually, we identified ten new O-GlcNAcylated proteins that were expressed during $\beta$ cell apoptosis, and analyzed the functional implications of these proteins in relation to pancreatic $\beta$ cell dysfunction.

• Asian-Australasian Journal of Animal Sciences
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• 제15권6호
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• pp.783-788
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• 2002

Bovine yolk sac at day 24 of pregnancy, and placental membranes (chorion and allantois) from days 70 and 100 of pregnancy were isolated and cultured in a modified minimum essential medium in the presence of $[^{35}S]$methionine. Proteins synthesized and secreted by isolated bovine yolk sac, chorion and allantois were analyzed by fluorography of two-dimensional polyacrylamide gel electrophoresis. Serum-like proteins,transferrin, ${\alpha}$-fetoprotein, ${\alpha}$1-antitrypsin and ${\alpha}$1-acid glycoprotein,were the major protein products of yolk sac. A 21 kDa protein produced by yolk sac was identified immunochemically as retinol-binding protein (RBP). Chorion and allantios from days 70 and 100 of pregnancy were active in protein synthesis and secretion. Both chorion and allantois did not secret serum-like proteins but secreted a number of neutral-to-acidic proteins including RBP. Secretory proteins produced by the yolk sac, chorion and allantois may play important roles in the embryonic development and the successful outcome of pregnancy. Antiserum against bovine placental RBP was employed to the immunocytochemistry by immunoperoxidase method. Immunoreactive RBP was localized in epithelial cells and island-like cell clones of yolk sac. Immunostaining for RBP was detected in simple columnar epithelium of chorion and in simple squamous epithelium of allantois. In the present study, proteins synthesized and secreted by yolk sac at day 24 of pregnancy, chorion and allantois from days 70 and 100 of pregnancy were characterized In addition, RBP was localized in yolk sac, chorion and allantois by immunoperoxidase method. The immunoperoxidase method has been proven to be a very effective technique to identify the cellular source of protein synthesis in extraembryonic membranes.

• 한국가축번식학회지
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• 제27권4호
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• pp.299-307
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• 2003

The effects of additions/deletions in glycosylated residues of recombinant human EPO (rhEPO) produced in CHO-K1 on their secretion were examined. hEPO cDNA was amplified from human liver mRNA and cloned into the pCR2.1 TOPO. Using overlapping-extension site-directed mutagenesis method, glycosylation sites at 24th, 38th, 83rd, and 126th were respectively or accumulatively removed by substituting its asparagine (or serine) with glutamine. To add novel glycosylation sites, 69 and 105th leucine was mutated to asparagine. Mutant and wild type rhEPO constructs were cloned into the pcDNA3 expression vector with CMV promoter and transfected into CHO cell line, CHO-K1, to produce mutant rhEPO mutant rhEPO proteins. Enzyme-linked immunosorbant assay (ELISA) and Western analysis with monoclonal anti-EPO antibody were performed using supernatants of the cultures showing transient and stable expressions respectively. Addition of novel glycosylation reduced rhEPO secretion dramatically while deletion mutants had little effect except some double deletion mutants ($\Delta$24/83 and $\Delta$38/83) and triple mutant ($\Delta$24/38/83). This fact suggests that not single but combination of changes in glycosyl groups affect secretion of rhEPO in cell culture, possibly via changes in their conformations.