Role of Arg-Gingipain A in Virulence of Porphyromonas gingivalis

ABSTRACT In order to access the role of the Porphyromonas gingivalis Arg-gingipain proteases in the virulence of this organism, a mutant defective in the rgpA gene was constructed in strain 381. This mutant, MT10, displayed only 40% of the Arg-specific cysteine protease activity of the wild-type strain. In addition, MT10, as well as the recently characterized protease mutant G-102, which is defective in the rgpB gene, displayed reduced self-aggregation, hemagglutination, and the ability to bind to immobilized type I collagen compared to levels of the wild-type parent. However, unlike mutant G-102, the rgpA mutant displayed increased binding to epithelial cells relative to that of the parental organism. Mutant MT10 also did not express detectable levels of the FimA protein as assessed by both Western and Northern blotting or fimbriae visible by electron microscopy of the cells. Furthermore, the ability of MT10 to degrade rat tail collagen fibers when it was cultured at 37°C was markedly attenuated compared to that of strain 381. These results suggest that Arg-gingipain A may play a significant role in the pathogenicity of P. gingivalis by altering the colonization and toxic properties of the organism.

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Fibronectin binding site in type I collagen regulates fibronectin fibril formation.

The Journal of Cell Biology ◽

10.1083/jcb.121.5.1165 ◽

1993 ◽

Vol 121 (5) ◽

pp. 1165-1172 ◽

Cited By ~ 94

Author(s):

B J Dzamba ◽

H Wu ◽

R Jaenisch ◽

D M Peters

Keyword(s):

Binding Site ◽

Type I Collagen ◽

Sparse Matrix ◽

Type I ◽

Collagen Gene ◽

Wild Type ◽

Binding Region ◽

Fibronectin Binding ◽

Fibronectin Fibrils

Mov13 fibroblasts, which do not express endogenous alpha 1(I) collagen chains due to a retroviral insertion, were used to study the role of type I collagen in the process of fibronectin fibrillogenesis. While Mov13 cells produced a sparse matrix containing short fibronectin fibrils, transfection with a wild type pro alpha 1(I) collagen gene resulted in the production of an extensive matrix containing fibronectin fibrils of normal length. To study the amino acids involved in the fibronectin-collagen interaction, mutations were introduced into the known fibronectin binding region of the pro alpha 1(I) collagen gene. Substitution of Gln and Ala at positions 774 and 777 of the alpha 1(I) chain for Pro resulted in the formation of short fibronectin fibrils similar to what was observed in untransfected Mov13 cells. Type I collagen carrying these substitutions bound weakly to fibronectin-sepharose and could be eluted off with 1 M urea. The effect of this mutation on fibronectin fibrillogenesis could be rescued by adding either type I collagen or a peptide fragment (CB.7) which contained the wild type fibronectin binding region of the alpha 1(I) chain to the cell culture. These results suggest that fibronectin fibrillogenesis in tissue culture is dependent on type I collagen synthesis, and define an important role for the fibronectin binding site in this process.

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Role of vimA in cell surface biogenesis in Porphyromonas gingivalis

Microbiology ◽

10.1099/mic.0.038331-0 ◽

2010 ◽

Vol 156 (7) ◽

pp. 2180-2193 ◽

Cited By ~ 13

Author(s):

Devon O. Osbourne ◽

Wilson Aruni ◽

Francis Roy ◽

Christopher Perry ◽

Lawrence Sandberg ◽

...

Keyword(s):

Cell Surface ◽

Outer Membrane ◽

Porphyromonas Gingivalis ◽

Type Strain ◽

Wild Type Strain ◽

Phenotypic Expression ◽

Surface Proteins ◽

Wild Type ◽

In The Wild

The Porphyromonas gingivalis vimA gene has been previously shown to play a significant role in the biogenesis of gingipains. Further, in P. gingivalis FLL92, a vimA-defective mutant, there was increased auto-aggregation, suggesting alteration in membrane surface proteins. In order to determine the role of the VimA protein in cell surface biogenesis, the surface morphology of P. gingivalis FLL92 was further characterized. Transmission electron microscopy demonstrated abundant fimbrial appendages and a less well defined and irregular capsule in FLL92 compared with the wild-type. In addition, atomic force microscopy showed that the wild-type had a smoother surface compared with FLL92. Western blot analysis using anti-FimA antibodies showed a 41 kDa immunoreactive protein band in P. gingivalis FLL92 which was missing in the wild-type P. gingivalis W83 strain. There was increased sensitivity to globomycin and vancomycin in FLL92 compared with the wild-type. Outer membrane fractions from FLL92 had a modified lectin-binding profile. Furthermore, in contrast with the wild-type strain, nine proteins were missing from the outer membrane fraction of FLL92, while 20 proteins present in that fraction from FLL92 were missing in the wild-type strain. Taken together, these results suggest that the VimA protein affects capsular synthesis and fimbrial phenotypic expression, and plays a role in the glycosylation and anchorage of several surface proteins.

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Formation of Methyl Mercaptan froml-Methionine by Porphyromonas gingivalis

Infection and Immunity ◽

10.1128/iai.68.12.6912-6916.2000 ◽

2000 ◽

Vol 68 (12) ◽

pp. 6912-6916 ◽

Cited By ~ 93

Author(s):

Mamiko Yoshimura ◽

Yoshio Nakano ◽

Yoshihisa Yamashita ◽

Takahiko Oho ◽

Toshiyuki Saito ◽

...

Keyword(s):

Porphyromonas Gingivalis ◽

Wild Type Strain ◽

Marked Decrease ◽

Oral Bacteria ◽

Methyl Mercaptan ◽

Wild Type ◽

Oral Malodor ◽

Gene Encoding ◽

Degradation Activity

ABSTRACT Methyl mercaptan production by oral bacteria is thought to be one of the main causes of oral malodor. We examined the ability of periodontopathic Porphyromonas gingivalis to produce methyl mercaptan from l-methionine and found that the invasive strains W83 and W50 produced large amounts of methyl mercaptan. We cloned and sequenced the mgl gene encodingl-methionine-α-deamino-γ-mercaptomethane-lyase (METase) from P. gingivalis W83. The structural mgl gene consisted of 1,200 bp and encoded a 43.3-kDa protein. To examine the role of methyl mercaptan in the pathogenesis ofP. gingivalis, a METase-deficient mutant of P. gingivalis W83 was constructed. The methionine degradation activity and virulence of the mutant (M1217) and the parent strain (W83) in mice were compared. M1217 showed a marked decrease in the formation of methyl mercaptan from l-methionine and decreased virulence compared with the wild-type strain W83. These results suggest that methyl mercaptan not only is one of the sources of oral malodor, but may also play a role in the pathogenicity of P. gingivalis.

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Role of prokaryotic type I and III pantothenate kinases in the coenzyme A biosynthetic pathway of Bacillus subtilis

Canadian Journal of Microbiology ◽

10.1139/cjm-2013-0793 ◽

2014 ◽

Vol 60 (5) ◽

pp. 297-305 ◽

Cited By ~ 5

Author(s):

Yuta Ogata ◽

Hiroki Katoh ◽

Munehiko Asayama ◽

Shigeru Chohnan

Keyword(s):

Bacillus Subtilis ◽

Recombinant Proteins ◽

Biosynthetic Pathway ◽

Kinase Activity ◽

Wild Type Strain ◽

Coenzyme A ◽

Monovalent Cation ◽

Type I ◽

Wild Type

Pantothenate kinases (CoaAs) catalyze the phosphorylation of pantothenate in the first step of the coenzyme A (CoA) biosynthetic pathway. These bacterial enzymes have been categorized into 3 types, the prokaryotic type I, II, and III CoaAs. Bacteria typically carry a single CoaA gene on their genome, but Bacillus subtilis possesses 2 proteins homologous to type I and III CoaAs, known as BsCoaA and BsCoaX, respectively. Both recombinant proteins exhibited the expected kinase activity and the characteristic properties of type I and III CoaAs, i.e., regulation by CoASH and acyl-CoAs in BsCoaA and the requirement of a monovalent cation in BsCoaX. Both gene disruptants appeared to grow in a manner similar to the wild-type strain. With the BsCoaX disruptant, the BsCoaA had the ability to completely fill the intracellular CoA pool, whereas the BsCoaA disruptant did not. These findings clearly indicate that these 2 CoaAs are employed together in the CoA biosynthetic pathway in B. subtilis and that the contribution of the type I CoaA (BsCoaA) to the formation of the intracellular CoA pool is larger than that of the type III CoaA (BsCoaX).

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Faculty Opinions recommendation of Pivotal role of connective tissue growth factor in lung fibrosis: MAPK-dependent transcriptional activation of type I collagen.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.717970990.793469383 ◽

2013 ◽

Author(s):

Achsah Keegan

Keyword(s):

Growth Factor ◽

Connective Tissue ◽

Connective Tissue Growth Factor ◽

Transcriptional Activation ◽

Lung Fibrosis ◽

Type I Collagen ◽

Tissue Growth ◽

Pivotal Role ◽

Type I

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The Dynamic Interaction between Extracellular Matrix Remodeling and Breast Tumor Progression

Cells ◽

10.3390/cells10051046 ◽

2021 ◽

Vol 10 (5) ◽

pp. 1046

Author(s):

Jorge Martinez ◽

Patricio C. Smith

Keyword(s):

Extracellular Matrix ◽

Type I Collagen ◽

Cell Metabolism ◽

Breast Tumors ◽

Extracellular Matrix Remodeling ◽

Type I ◽

Matrix Remodeling ◽

Desmoplastic Reaction ◽

The Impact

Desmoplastic tumors correspond to a unique tissue structure characterized by the abnormal deposition of extracellular matrix. Breast tumors are a typical example of this type of lesion, a property that allows its palpation and early detection. Fibrillar type I collagen is a major component of tumor desmoplasia and its accumulation is causally linked to tumor cell survival and metastasis. For many years, the desmoplastic phenomenon was considered to be a reaction and response of the host tissue against tumor cells and, accordingly, designated as “desmoplastic reaction”. This notion has been challenged in the last decades when desmoplastic tissue was detected in breast tissue in the absence of tumor. This finding suggests that desmoplasia is a preexisting condition that stimulates the development of a malignant phenotype. With this perspective, in the present review, we analyze the role of extracellular matrix remodeling in the development of the desmoplastic response. Importantly, during the discussion, we also analyze the impact of obesity and cell metabolism as critical drivers of tissue remodeling during the development of desmoplasia. New knowledge derived from the dynamic remodeling of the extracellular matrix may lead to novel targets of interest for early diagnosis or therapy in the context of breast tumors.

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Enhanced production of Clavulanic acid by improving glycerol utilization using reporter-guided mutagenesis of an industrial Streptomyces clavuligerus strain

Journal of Industrial Microbiology & Biotechnology ◽

10.1093/jimb/kuab004 ◽

2021 ◽

Author(s):

Chang-Hun Shin ◽

Hang Soo Cho ◽

Hyung-Jin Won ◽

Ho Jeong Kwon ◽

Chan-Wha Kim ◽

...

Keyword(s):

Clavulanic Acid ◽

Wild Type Strain ◽

Random Mutagenesis ◽

Streptomyces Clavuligerus ◽

Wild Type ◽

Mutant Selection ◽

Enhanced Production ◽

Industrial Strains ◽

Glycerol Utilization

Abstract Clavulanic acid (CA) produced by Streptomyces clavuligerus is a clinically important β-lactamase inhibitor. It is known that glycerol utilization can significantly improve cell growth and CA production of S. clavuligerus. We found that the industrial CA-producing S. clavuligerus strain OR generated by random mutagenesis consumes less glycerol than the wild-type strain; we then developed a mutant strain in which the glycerol utilization operon is overexpressed, as compared to the parent OR strain, through iterative random mutagenesis and reporter-guided selection. The CA production of the resulting S. clavuligerus ORUN strain was increased by approximately 31.3 per cent (5.21 ± 0.26 g/L) in a flask culture and 17.4 per cent (6.11 ± 0.36 g/L) in a fermenter culture, as compared to that of the starting OR strain. These results confirmed the important role of glycerol utilization in CA production and demonstrated that reporter-guided mutant selection is an efficient method for further improvement of randomly mutagenized industrial strains.

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