• Journal of Microbiology and Biotechnology
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• v.27 no.9
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• pp.1609-1616
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• 2017

The complex roles of cell surface modification in the biofilm formation of Campylobacter jejuni, a major cause of worldwide foodborne diarrheal disease, are poorly understood. In a screen of mutants from random transposon mutagenesis, an insertional mutation in the eptC gene (cj0256) resulted in a significant decrease in C. jejuni NCTC11168 biofilm formation (<20%) on major food contact surfaces, such as polystyrene and borosilicate glass, when compared with wild-type cells (p < 0.05). In C. jejuni strain 81-176, the protein encoded by eptC modified cell surface structures, such as lipid A, the inner core of lipooligosaccharide, and the flagellar rod protein (FlgG), by attaching phosphoethanolamine. To assess the role of eptC in C. jejuni NCTC11168, adherence and motility tests were performed. In adhesion assays with glass surfaces, the eptC mutant exhibited a $0.77log\;CFU/cm^2$ decrease in adherence compared with wild-type cells during the initial 2 h of the assay (p < 0.05). These results support the hypothesis that the modification of cell surface structures by eptC affects the initial adherence in biofilm formation of C. jejuni NCTC11168. In motility tests, the eptC mutant demonstrated reduced motility when compared with wild-type cells, but wild-type cells with the transposon inserted in a gene irrelevant to biofilm formation (cj1111c) also exhibited decreased motility to a similar extent as the eptC mutant. This suggests that although eptC affects motility, it does not significantly affect biofilm formation. This study demonstrates that eptC is essential for initial adherence, and plays a significant role in the biofilm formation of C. jejuni NCTC11168.

• Journal of Microbiology and Biotechnology
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• v.17 no.4
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• pp.695-700
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• 2007

The cycloinulooligosaccharide fructanotransferase (CFTase) gene (cft) from Paenibacillus macerans (GenBank access code AF222787) was expressed on the cell surface of Saccharomyces cerevisiae by fusing with Aga2p linked to the membrane-anchored protein Aga1p. The surface display of CFTase was confirmed by immunofluorescence microscopy and enzymatic assay. The optimized reaction conditions of surface-displayed CFTase were as follows; pH, 8.0; temperature, $50^{\circ}C$; enzyme amount, 30 milliunit; substrate concentration, 5%; inulin source, Jerusalem artichoke. As a result of the reaction with inulin, cycloinulohexaose was produced as a major product along with cycloinuloheptaose and cycloinulooctaose as minor products.

• The Plant Pathology Journal
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• v.25 no.4
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• pp.333-343
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• 2009

Here, we show that an endophytic bacterial strain, Enterobacter asburiae B1 exhibits the ability to elicit ISR in cucumber, tobacco and Arabidopsis thaliana. This indicates that strain B1 has a widespread ability to elicit ISR on various host plants. In this study, E. asburiae strain B1 did not show antifungal activity against tested major fungal pathogens, Colletotrichum orbiculare, Botrytis cinerea, Phytophthora capsici, Rhizoctonia solani, and Fusarium oxysporum. Moreover, the siderophore production by E. asburiae strain B1 was observed under in vitro condition. In greenhouse experiments, the root treatment of strain B1 significantly reduced disease severity of cucumber anthracnose caused by fungal pathogen C. orbiculare compared to nontreated control plants. By root treatment of strain B1 more than 50% disease control against anthracnose on cucumber was observed in all greenhouse experiments. Simultaneously, under the greenhouse condition, the soil drench of strain B1 and a chemical inducer benzothiadiazole (BTH) to tobacco plants induced GUS activity which is linked with activation of PR promoter gene. Furthermore, in Arabidopsis thaliana plants the soil drench of strain B1 induced the defense gene expression of PR1 and PDF1.2 related to salicylic acid and jasmonic acid/ethylene signaling pathways, respectively. In this study, for the main focus on root colonization by strain B1 associated with defense responses, bacterial cells of strain B1 was tagged with the gfp gene encoding the green fluorescent protein in order to determine the colonization pattern of strain B1 in cucumber. The gfp-tagged B1 cells were found on root surface and internal colonization in root, stem, and leaf. In addition to this, the scanning electron microscopy observation showed that E. asburiae strain B1 was able to colonized cucumber root surface.

• BMB Reports
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• v.33 no.3
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• pp.242-248
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• 2000

Phage display of proteins is a powerful tool for protein engineering since a vast library of sequences can be rapidly screened for a specific property. In this study, we develop da new phage display vector that was derived from a pET-25b(+) vector. The pET-25b(+) was modified in order that the expressed protein would have a T7-tag at the amino terminus and GpS (a major coat protein of M13 phage) at the carboxyl terminus. Another vector without the gp8 gene was also constructed. The newly developed phagemid vectors have several advantageous features. First, it is easy to examine whether or not the target proteins are functional and faithfully transported into the periplasmic space. This feature is due to the fact that recombinant proteins are produced abundantly in the pET system. Second, the T7-tag makes it possible to detect any target proteins that are displayed on the surface of filamentous bacteriophage. To verify the utility of the vector, the clones containing the glutathione S-transferase (GST) gene as a target were examined. The result showed that the GST produced from the recombinant vector was successfully transported into the periplasmic space and had the anticipated enzyme activity. Western blot analysis using a T7-tag antibody also showed the presence of the target protein displayed on the surface of the phage. The phages prepared from the recombinant clones were able to bind to glutathione-Sepharose and then eluted with glutathione. These results showed that the new vectors developed in this study are useful for the phage display of proteins.

• International Journal of Oral Biology
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• v.36 no.2
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• pp.91-101
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• 2011

MspTL is the major surface protein of Treponema lecithinolyticum associated with periodontitis and endodontic infections. Our recent investigation revealed that MspTL induces proinflammatory cytokines and intercellular adhesion molecule 1 in THP-1 cells and periodontal ligament cells. In this study we conducted oligonucleotide microarray analysis to investigate the global transcriptional regulation in THP-1 cells stimulated with purified recombinant MspTL. MspTL upregulated the expression of 90 genes in THP-1 cells at least four fold, and the functions of these genes were categorized into adhesion, apoptosis/antiapoptosis, cell cycle/growth/differentiation, chemotaxis, cytoskeleton organization, immune response, molecular metabolism, proteolysis, signaling, and transcription. The majority of the modified genes are known to be NF-${\kappa}B$-responsive and interferon-stimulated genes (ISGs). The expression of 12 selected genes was confirmed by real-time RT-PCR. Because prostaglandin $E_2(PGE_2)$ is an important inflammatory mediator and Cox-2 was found to be induced by MspTL in the microarray analysis, we determined the level of $PGE_2$ in the culture supernatants of MspTL-treated cells and found that MspTL significantly increased $PGE_2$. Our results provide insight into the gene regulation of host cells in response to MspTL, and may contribute to the understanding of the molecular mechanism in periodontitis.

• Journal of Microbiology and Biotechnology
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• v.16 no.3
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• pp.360-367
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• 2006

The endoinulinase gene (inu1) from Pseudomonas mucidolens was expressed on the cell surface of Saccharomyces cerevisiae by fusing with Aga2p linked to the membrane anchored protein, Aga1p. The inu1 gene of P. mucidolens was subcloned into the surface display vector, pCTcon (GAL1 promoter). The constructed plasmid, pCTENIU (8.5kb), was then introduced to S. cerevisiae EBY100 cells and the yeast transformants selected on synthetic defined media lacking uracil and inulin-containing media. The inu1 gene under the control of the GAL1 promoter was successfully expressed in the yeast transformants, and the surface display of endoinulinase confirmed by immunofluorescence microscopy, along with its enzymatic ability to form inulooligosaccharides (IOSs) from inulin. The total endoinulinase activity reached about 2.31 units/ml when the yeast transform ants were cultivated on a YPDG medium. To efficiently hydrolyze the inulin, various reaction conditions were examined, including the pH, temperature, and inulin source. The optimized conditions were then determined as follows: pH, 7.0; temperature, $50^{\circ}C$; inulin source, Jerusalem artichoke. Under the optimized condition and 46 units of endoinulinase per g of inulin, IOSs started to be produced after 10 min of enzymatic reaction. The highest yield, 71.2% of IOSs, was achieved after 30 h of reaction without any significant loss of the initial enzyme activity. As a result of the reaction with inulin, IOSs consisting of inulobiose (F2), inulotriose (F3), inulotetraose (F4), and inulopentaose (F5) were produced, and F4 was the major product.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.19-19
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• 2001

Mammalian urothelium undergoes unique membrane specialization by making the asymmetric unit membrane (AUM) that is covered with the apical cell surface during terminal differentiation. The AUM contains several major integral membrane proteins including uroplakin Ia, Ib, II and III. The genes for uroplakins have been cloned from humans and mice, but not from porcine. In this study, we report the cloning of the UPII genomic DNA, which codes for the full length open reading frame for the uroplakin II protein. The deduced amino acid sequence encodes of a hydrophobic NH$_2$-terminal peptide, a prosequence, and a mature protein. The prosequence contains three potential N-glycosylation sites and a RGRR cleavage site that may be involved in uroplakin II processing and maturation. Northern and immunohistochemistry analyses showed that the porcine UPII gene is only expressed in urothelium and that the protein was specifically localized in urothelial superficial cells. A 2kb of upstream in the promoter sequence contains multiple transcription factor binding sites, including GC-box, SPI, AP2, and GATA-box sites, but not for TATA or CAAT-box sequences. Comparison of the porcine UPII promoter sequence with that of the murine by MEME system presented two conserved motifs, suggesting a cis-acting regulatory role for the conserved sequences. Sequence homology between two species in motif A and B was 79% and 80% respectively, although their relative locations were different. During the gestation, mouse bladder at estrus stages and day 10 after parturition showed higher UPII expression, while showed lower expression at peri-implantation stage. Taken together, our results showed that the porcine UPII gene was expressed highly and specifically in the bladder urothelium and that steroid hormones for implantation changed the expression of UPII in the bladder, although the biological significance of UPII remains to be not determined.

• BMB Reports
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• v.31 no.3
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• pp.240-244
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• 1998

Helicobacter pylori is the etiologic agent of human gastritis and peptic ulceration and produces urease as the major protein component on its surface. H. pylori urease is known to serve as a major virulence factor and in a potent immunogen. In order to express the recombinant urease at a higher level, a DNA fragment containing the minimal H. pylori urease gene cluster was subcloned into a high copy-number vector. The recombinant H. pylori urease expressed in an E. coli strain that was grown in a rich medium supplemented with added nickel was purified to near homogeneity by using DEAE-Sepharose, Superdex HR200, and Mono-Q (FPLC) columns and the purified enzyme possessed the specific activity of 1255 U/mg. Polyclonal antibodies raised against the purified recombinant H. pylori urease were shown to be very specific when subjected to Western blot analysis, in which crude extracts from the H. pylori ATCC strain and the recombinant E. coli strains expressing various bacterial ureases were exnmined for cross-reactivity.

• Parasites, Hosts and Diseases
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• v.39 no.3
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• pp.241-246
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• 2001

The antigenic domain of the major surface protein (Nc-p43) of Neospora caninum was examined by polymerase chain reaction of its gene fragments and recombinant expression as GST fusion proteins. The fragments of Nc-p43 were as follow: a total open reading frame (OFR), T: OFR without signal sequence and C-terminal hydrophobic sequence, S: N-terminal 2/3 parts of S, A: C-terminal 2/3 parts, P; N-terminal 1/3 part, X: middle 1/3 part Y; and C-terminal 1/3 part, Z, respectively. The DNA fragments were cloned into pGEX-47 vector. Recombinant plasmids transformed into Escherichia coli of BL21 pLysS (DE3) strain were induced to express GST or GST fused fragments of Nc-p43 such as 69 kDa protein for T,66 kDa for S, 52 kDa for A,53 kDa for P, and 40 kDa proteins for X, Y, and Z, respectively in SDS-PAGE. The Nc-p43 fragments of T, S, and P reacted with a bovine serum of neosporosis while those of A, X, Y, and Z together with GST did not in the western blot. These findings suggest that the antigenic domain of Nc-p43 of N. caninum may be localized in the C-terminal 2/3 parts. Together with Al9 clone in SAGI of Toxoplasma gondii (Nam et at., 1996), the P fragment of Nc-p43 could be used as efficient antigens to diagnose and differentiate those infections with both species .

• Journal of Microbiology and Biotechnology
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• v.18 no.4
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• pp.658-662
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• 2008

Effects of pH shock on the secretion system of S. coelicolor A3(2) have been investigated at a transcriptional level by using DNA microarrays. Actinorhodin secretion was observed to be highly enhanced when an acidic-pH shock was applied to surface grown cultures of S. coelicolor A3(2). In this culture, a gene of actVA-orf1 encoding a putative efflux pump or transporter protein for actinorhodin was strongly upregulated. A major number of efflux pumps for other metabolites and a major number of secretion proteins for protein secretion were also observed to be upregulated with pH shock. The secretion of actinorhodin was observed to be remarkably enhanced in liquid culture as well.