• Journal of Microbiology and Biotechnology
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• 제21권2호
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• pp.197-203
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• 2011

Lactobacilli are normal constituents of the intestinal microbiota, and some strains show the capacity to bind to extracellular matrix proteins and components of the mucosal layer, which represents an adaptation to persist in this niche. A shotgun phage-display library of Lactobacillus casei BL23 was constructed and screened for peptides able to bind to fibronectin and collagen. Clones showing binding to these proteins were isolated, which encoded overlapping fragments of a putative transcriptional regulator (LCABL_29260), a hypothetical protein exclusively found in the L. casei/rhamnosus group (LCABL_01820), and a putative phage-related endolysin (LCABL_13470). The construction of different glutathione S-transferase (GST) fusions confirmed the binding activity and demonstrated that the three identified proteins could interact with fibronectin, fibrinogen, and collagen. The results illustrate the utility of phage display for the isolation of putative adhesins in lactobacilli. However, it remains to be determined whether the primary function of these proteins actually is adhesion to mucosal surfaces.

• BMB Reports
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• 제46권3호
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• pp.139-150
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• 2013

The ADAM and ADAMTS families, also called adamalysins belong to an important group of extracellular matrix proteins. The ADAMs family belong to both the transmembrane and secreted proteins, while ADAMTS family only contains secreted forms. Adamalysins play an important role in the cell phenotype regulation via their activities in signaling pathways, cell adhesion and migration. The human proteome contains 21 ADAM, and 19 ADAMTS proteins, which are involved in extracellular matrix remodeling, shedding of various substrates such as: adhesion ligands, growth factors, their receptors and diverse cytokines. Recent studies provide evidence that adamalysins play a crucial role in colorectal cancer (CRC) etiopathogenesis. It seems possible that adamalysins might be used as CRC prediction markers or potential pharmaceutical targets.

• The Korean Journal of Physiology and Pharmacology
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• 제15권4호
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• pp.245-249
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• 2011

Amphetamine, a synthetic psychostimulant, is transported by the dopamine transporter (DAT) to the cytosol and increases the exchange of extracellular amphetamine by intracellular dopamine. Recently, we reported that the phosphorylation levels of ezrin-radixin-moesin (ERM) proteins are regulated by psychostimulant drugs in the nucleus accumbens, a brain area important for drug addiction. However, the significance of ERM proteins phosphorylation in response to drugs of abuse has not been fully investigated. In this study, using PC12 cells as an in vitro cell model, we showed that amphetamine increases ERM proteins phosphorylation and protein kinase C (PKC) ${\beta}$ inhibitor, but not extracellular signal-regulated kinase (ERK) or phosphatidylinositol 3-kinases (PI3K) inhibitors, abolished this effect. Further, we observed that DAT inhibitor suppressed amphetamine-induced ERM proteins phosphorylation in PC12 cells. These results suggest that $PKC{\beta}$-induced DAT regulation may be involved in amphetmaine-induced ERM proteins phosphorylation.

• Animal cells and systems
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• 제14권4호
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• pp.261-266
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• 2010

PC12 cells were differentiated into the cells of chromaffin phenotype by butyrate treatment. Cells were aggregated and formed tight cell adhesion. To investigate the molecular change in this differentiation, we examined expression levels of cell adhesion proteins and extracellular proteins during butyrate induced-differentiation of PC12 cells. Integrin ${\beta}1$, integrin ${\alpha}7$, E cadherin, VCAM, collagen-I, fibronectin, desmoglein and connexin were increased during differentiation. The levels of clusterin and secreted clusterin were also increased. These increased levels of cell adhesion proteins and extracellular proteins appear to induce cell aggregation and tight cell adhesion. The levels of p21, p27 and p16 were increased probably because of differentiation-related growth arrest during differentiation. Prolonged incubation of butyrate up to 1 day was required for differentiation. Signal transduction pathways for this differentiatiom could not be identified since various inhibitors had no effect. The results showed that butyrateinduced differentiation of PC12 cells to chromaffin cells involves tight cell adhesion and induction of extracellular proteins and cell adhesion proteins.

• Journal of Microbiology and Biotechnology
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• 제20권6호
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• pp.978-984
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• 2010

This paper examines the probiotic bacterium Lactobacillus rhamnosus GG, and how it reacts to the presence of mucin in its extracellular milieu. Parameters studied included cell clustering, adhesion to mucin, extracellular protein production, and formation of final metabolites. L. rhamnosus GG was found to grow efficiently in the presence of glucose, N-acetylglucosamine, or mucin (partially purified or purified) as sole carbon sources. However, it was unable to grow using other mucin constituents, such as fucose or glucuronic acid. Mucin induced noticeable changes in all the parameters studied when compared with growth using glucose, including in the formation of cell clusters, which were easily disorganized with trypsin. Mucin increased adhesion of the bacterium, and modulated the production of extracellular proteins. SDS-PAGE revealed that mucin was not degraded during L. rhamnosus GG growth, suggesting that this bacterium is able to partially use the glucidic moiety of glycoprotein. This study goes some way towards developing an understanding of the metabolic and physiological changes that L. rhamnosus GG undergoes within the human gastrointestinal tract.

• Journal of Microbiology and Biotechnology
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• 제27권4호
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• pp.791-807
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• 2017

The type II secretion system (T2SS), which transports selected periplasmic proteins across the outer membrane, has rarely been studied in nonpathogens or in organisms classified as Betaproteobacteria. Therefore, we studied Cupriavidus metallidurans (Cme), a facultative chemilithoautotroph. Gel analysis of extracellular proteins revealed no remarkable differences between the wild type and the T2SS mutants. However, enzyme assays revealed that native extracellular alkaline phosphatase is a T2SS substrate, because activity was 10-fold greater for the wild type than a T2SS mutant. In Cme engineered to produce three Ralstonia solanacearum (Rso) exoenzymes, at least 95% of their total activities were extracellular, but unexpectedly high percentages of these exoenzymes remained extracellular in T2SS mutants cultured in rich broth. These conditions appear to permit an alternative secretion process, because neither cell lysis nor periplasmic leakage was observed when Cme produced a Pectobacterium carotovorum exoenzyme, and wild-type Cme cultured in minimal medium secreted 98% of Rso polygalacturonase, but 92% of this exoenzyme remained intracellular in T2SS mutants. We concluded that Cme has a functional T2SS despite lacking any abundant native T2SS substrates. The efficient secretion of three foreign exoenzymes by Cme is remarkable, but so too is the indication of an alternative secretion process in rich culture conditions. When not transiting the T2SS, we suggest that Rso exoenzymes are probably selectively packaged into outer membrane vesicles. Phylogenetic analysis of T2SS proteins supports the existence of at least three T2SS subfamilies, and we propose that Cme, as a representative of the Betaproteobacteria, could become a new useful model system for studying T2SS substrate specificity.

• 대한의용생체공학회:의공학회지
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• 제45권1호
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• pp.20-25
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• 2024

Extracellular vesicles (EVs) are nano-sized lipid bilayer vesicles released by cells. EVs act as messengers for cell-to-cell communication. Inside, it contains various substances that show biological activity, such as proteins, lipids, nucleic acids, and metabolites. The study of EVs extracted from terrestrial organisms and stem cells on inflammatory environments and tissue regeneration have been actively conducted. However, marine organisms-derived EVs are limited. Therefore, we have extracted EVs from sea urchins belonging to the Echinoderm group with their excellent regenerative ability. First, we extracted extracellular matrix (ECM) from sea urchin gonads treated with hypotonic buffer, followed by collagenase treatment, and filtration to collect ECM-bounded EVs. The size of sea urchin gonad-derived EVs (UGEVs) is about 20-100 nm and has a round shape. The protein content was higher after EVs burst than before, which is evidence that proteins are contained inside. In addition, proteins of various sizes are distributed inside. PKH-26 was combined with UGEVs, which means that UGEVs have a lipid membrane. PHK-26-labeled UGEVs were successfully uptaken by cells. UGEVs can be confirmed to have the same characteristics as traditional EVs. Finally, it was confirmed that Schwann cells were not toxic by increasing proliferation after treatment.

• 한국식물병리학회지
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• 제11권4호
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• pp.318-323
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• 1995

The effect of AF-toxin I produced by the strawberry pathotype of Alternaria alternata on the protein synthesis of susceptible strawberry protoplasts was examined by using the radiolabeled amino acids. The incorporation of the radiolabeled amino acids into newly synthesized proteins in the strawberry protoplasts was stimulated by the toxin treatment at relatively low concentrations (2.2$\times$10-11 to 2.2$\times$10-9 M), but not at higher concentrations (2.2$\times$10-8 to 2.2$\times$10-6 M). An one-dimensional SDS-polyacrylamide gel electrophoresis revealed no detectable differences in the proteins synthesized in both the toxintreated and untreated protoplasts. The susceptible strawberry protoplasts were treated with AF-toxin I and stained with Fluostain I to detect the extracellular polysaccharides. The toxin treatment induced the accumulation of extracellular polysccharides in a dose-dependent manner. These results indicate a transient activation of cellular metabolism in the susceptible cells by the toxin exposure.

• 한국수정란이식학회지
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• 제8권2호
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• pp.83-90
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• 1993

To investigate the effect of extracellular matrix proteins on the in vitro development of ethanol-induced parthenogenetic eggs of ICR strain mice, those were cultured in vitro in fibronectin, gelatin, or collagen precoated culture dishes containing 1.5 ml of NaH-C03$_3$-BMOC-3 medium at 37$^{\circ}C$ for 96 hrs. under the atmosphere of 5% $CO_2$ and 95% air. Fibronectin, gelatin, or collagen significantly(P$\pm$1.4, 45.4i1.4, and 44.8$\pm$O.9, respectively. And the diameter of those eggs ranged 104.6$\pm$1.9, 102.8$\pm$2.3, and 103.4$\pm$O.8 $\mu$m, respectively.

• KSBB Journal
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• 제25권3호
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• pp.257-264
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• 2010

Bone morphogenetic protein-7 (BMP-7) is one of important growth factors for skeletal development and bone growth. In this work, BMP-7 was efficiently expressed in recombinant Bacillus subtilis. The mature BMP-7 protein indicated molecular weight of 15.4 kDa by Western blot assay and was secreted into culture medium with 0.35 ng/mL. The extracellular and intracellular rhBMP-7 proteins were purified by using a FPLC system with an ion exchange column and a gel filtration column. The extracellular and intracellular rhBMP-7 proteins had finally a 57.1% purity and a 36.2% purity, respectively. The purified rhBMP-7 proteins showed an intact biological activity which stimulated alkaline phophatase (ALP) activity in MC3T3-E1 cells.