The acidic, glutamine-rich Mpn474 protein of Mycoplasma pneumoniae is surface exposed and covers the complete cell

Hegermann, Jan; Halbedel, Sven; Dumke, Roger; Regula, Jörg T.; Gabdoulline, Razif R.; Mayer, Frank; Stülke, Jörg; Herrmann, Richard

doi:10.1099/mic.0.2007/013342-0

Cited by 6 publications

(6 citation statements)

References 40 publications

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“…The M. pneumoniae strains used in this study were M. pneumoniae M129 (ATCC 29342) in the 32nd broth passage and its isogenic mutant derivatives GPM11 (prkC::mini-Tn, Gm r ), GPM51 (hprK::mini-Tn, Gm r ) (18), GPM68 (prpC::mini-Tn, Gm r ) (18), and GPM70 (MPN247::mini-Tn, Gm r ) (19). The oligonucleotides used in this study are listed in Table S1 in the supplemental material.…”

Section: Methodsmentioning

confidence: 99%

The Stability of Cytadherence Proteins in Mycoplasma pneumoniae Requires Activity of the Protein Kinase PrkC

et al. 2010

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Mycoplasma pneumoniae belongs to the mollicutes, a group of bacteria that have strongly reduced genomes but that are nevertheless capable of independent life. With only three transcription factors, the regulatory features of these bacteria are very limited. Thus, posttranslational regulation might be important for M. pneumoniae. In addition to the highly specific HPr kinase, the M. pneumoniae prkC gene encodes the serine/ threonine protein kinase C. In order to study the function(s) of this kinase, we isolated an M. pneumoniae mutant affected in PrkC. This mutation resulted in nonadherent growth and loss of cytotoxicity. Examination of the phosphorylation profile of the prkC mutant suggested that phosphorylation of cytadherence proteins was affected by the loss of this kinase. In contrast, inactivation of the prpC gene affecting the protein phosphatase that antagonizes PrkC-dependent phosphorylation resulted in more intensive phosphorylation of the cytadherence proteins HMW1 and HMW3 of the major adhesin P1 and of the surface protein MPN474. Moreover, loss of PrkC affects not only the phosphorylation state of the cytadherence proteins but also their intracellular accumulation. However, the expression of the corresponding genes was not affected by PrkC, suggesting that PrkC-dependent phosphorylation results in stabilization of the cytadherence proteins. The HMW proteins and P1 are part of the so-called terminal organelle of M. pneumoniae that is involved in gliding motility, cell division, and adhesion to host epithelial tissues. Our observations suggest that the posttranslational modification of cytadherence proteins by PrkC is essential for the development and function of the M. pneumoniae terminal organelle.Mycoplasma pneumoniae belongs to the mollicutes, i.e., cell wall-less bacteria. These organisms are among the smallest selfreplicating living beings capable of a host-independent existence. M. pneumoniae is a pathogenic bacterium that causes atypical pneumonia and extrapulmonary infections, such as autoimmune disorders, asthma, and arthritis (4,32,34).M. pneumoniae and its close relative Mycoplasma genitalium have recently attracted much attention, not only with respect to the elucidation of pathogenicity mechanisms but also because the small genomes of these bacteria define the lower limit of naturally existing independent life. The analysis of the minimal gene complement of M. pneumoniae and M. genitalium is one of the sources of synthetic biology, a new discipline of biology (12, 13).However, life is not static and not determined only by a defined set of genes. A very important feature is the control of biological activities in response to changing environmental conditions. Only this control enables organisms to adapt to different habitats and to survive suboptimal conditions. In M. pneumoniae, the regulatory potential seems to be rather limited. In bacteria, regulation of gene expression is achieved mainly at the level of transcription, by alternative sigma factors of the RNA polymerase, by transcriptio...

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Section: Methodsmentioning

confidence: 99%

The Stability of Cytadherence Proteins in Mycoplasma pneumoniae Requires Activity of the Protein Kinase PrkC

et al. 2010

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“…A total of 1 × 10 8 CCU/mL bacterial suspension was washed three times with ice-cold 0.1 M phosphate-buffered saline (PBS, pH 7.4) and finally resuspended in a volume of 50 μL of PBS. Immunoelectron microscopy was performed in triplicate according to protocols described in previous studies ( Hegermann et al, 2008 ; Chen et al, 2019 ) with some modifications. Briefly, 5 μL of the sample was added to a 400 mesh formvar-coated nickel grid and incubated for 5 min.…”

Section: Methodsmentioning

confidence: 99%

Nicotinamide Adenine Dinucleotide-Dependent Flavin Oxidoreductase of Mycoplasma hyopneumoniae Functions as a Potential Novel Virulence Factor and Not Only as a Metabolic Enzyme

et al. 2021

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Mycoplasma hyopneumoniae (Mhp) is the main pathogen that causes enzootic pneumonia, a disease that has a significant impact on the pig industry worldwide. The pathogenesis of enzootic pneumonia, especially possible virulence factors of Mhp, has still not been fully elucidated. The transcriptomic and proteomic analyses of different Mhp strains reported in the literature have revealed differences in virulence, and differences in RNA transcription levels between high- and low-virulence strains initially indicated that nicotinamide adenine dinucleotide (NADH)-dependent flavin oxidoreductase (NFOR) was related to Mhp pathogenicity. Prokaryotic expression and purification of the NFOR protein from Mhp were performed, a rabbit-derived polyclonal antibody against NFOR was prepared, and multiple sequence alignment and evolutionary analyses of Mhp NFOR were performed. For the first time, it was found that the NFOR protein was conserved among all Mhp strains, and NFOR was localized to the cell surface and could adhere to immortalized porcine bronchial epithelial cells (hTERT-PBECs). Adhesion to hTERT-PBECs could be specifically inhibited by an anti-NFOR polyclonal antibody, and the rates of adhesion to both high- and low-virulence strains, 168 and 168L, significantly decreased by more than 40%. Moreover, Mhp NFOR not only recognized and interacted with host fibronectin and plasminogen but also induced cellular oxidative stress and apoptosis in hTERT-PBECs. The release of lactate dehydrogenase by hTERT-PBECs incubated with Mhp NFOR was significantly positively correlated with the virulence of Mhp. Overall, in addition to being a metabolic enzyme related to oxidative stress, NFOR may also function as a potential novel virulence factor of Mhp, thus contributing to the pathogenesis of Mhp; these findings provide new ideas and theoretical support for studying the pathogenic mechanisms of other mycoplasmas.

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“…A total of 1×10 8 CCU of bacterial suspension was washed three times and nally resuspended in a volume of 50 µL of 0.1 M phosphate-buffered saline (PBS, pH 7.4). Immunoelectron microscopy was performed according to previous studies [25,26] with some modi cations. Brie y, 5 µL of the sample was added to a 400 mesh formvar-coated nickel grid and allowed to stand for 5 min.…”

Section: Surface-exposed Nfor Detection By Immunoelectron Microscopymentioning

confidence: 99%

NADH-Dependent Flavin Oxidoreductase of Mycoplasma Hyopneumoniae Functions as a Potential Novel Virulence Factor and not Only as a Metabolic Enzyme

Xie

Fei

Chen

et al. 2021

Preprint

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Background: Mycoplasma hyopneumoniae (Mhp) is the main pathogen of enzootic pneumonia, pigs infected with Mhp demonstrate mainly poor growth and a reduced feed conversion rate, a disease that has a significant impact on the pig industry and pock production worldwide. The pathogenesis, especially possible virulence factors of Mhp, has still not been fully clarified.Results: The transcriptome and proteomic analysis of Mhp strains differed in virulence based on reported literature, and RNA transcription expression levels between high- and low-virulence strains initially indicated that nicotinamide adenine dinucleotide (NADH)-dependent flavin oxidoreductase (NFOR) was related to Mhp pathogenicity. Prokaryotic expression and purification of the NFOR protein of Mhp were performed, a rabbit-origin polyclonal antibody of NFOR was prepared, and multiple sequence alignment and evolutionary analysis of Mhp NFOR were performed. For the first time, it was found that the NFOR protein was conserved among all Mhp strains, and NFOR was localized on the cell surface and could adhere to immortalized porcine bronchial epithelial cells (hTERT-PBECs). Adhesion to hTERT-PBECs could be specifically inhibited by an NFOR polyclonal antibody, and the adhesion rates of both high- and low-virulence strains, 168 and 168L, significantly decreased by more than 40%. Moreover, Mhp NFOR could not only recognize and interact with host fibronectin and plasminogen but could also induce cellular oxidative stress and apoptosis in hTERT-PBECs. Lactate dehydrogenase release of Mhp NFOR in hTERT-PBECs was significantly positively correlated with the virulence of Mhp.Conclusions: Overall, in addition to being a metabolic enzyme related to oxidative stress, NFOR may also function as a potential novel virulence factor of Mhp, thus contributing to the pathogenesis process of Mhp, providing new ideas and theoretical support for studying the pathogenic mechanisms of other mycoplasmas.

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The acidic, glutamine-rich Mpn474 protein of Mycoplasma pneumoniae is surface exposed and covers the complete cell

Cited by 6 publications

References 40 publications

The Stability of Cytadherence Proteins in Mycoplasma pneumoniae Requires Activity of the Protein Kinase PrkC

The Stability of Cytadherence Proteins in Mycoplasma pneumoniae Requires Activity of the Protein Kinase PrkC

Nicotinamide Adenine Dinucleotide-Dependent Flavin Oxidoreductase of Mycoplasma hyopneumoniae Functions as a Potential Novel Virulence Factor and Not Only as a Metabolic Enzyme

NADH-Dependent Flavin Oxidoreductase of Mycoplasma Hyopneumoniae Functions as a Potential Novel Virulence Factor and not Only as a Metabolic Enzyme

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