Outer membrane protein A and OprF: versatile roles in Gram‐negative bacterial infections

Krishnan, Subramanian; Prasadarao, Nemani V.

doi:10.1111/j.1742-4658.2012.08482.x

Cited by 118 publications

(89 citation statements)

References 67 publications

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“…Some of them, OmpA and OmpC especially, have already been identified as the main targets when E. coli cells are exposed to external oxidative stress (45). Recently, Krishnan and Prasadarao have shown that OmpA, which is a multifunctional major outer membrane protein of E. coli and the Enterobacteriaceae, interacts with specific receptors, initiating the pathogenesis of some Gram-negative bacterial infections (46). We hypothesized that the degradation of these mains OMPs by both the cytotoxic effect of TiO 2 and the ROS generated by the photocatalytic reaction on TiO 2 disrupts the communication between bacteria and the environment.…”

Section: Discussionmentioning

confidence: 99%

TiO ₂ Photocatalysis Damages Lipids and Proteins in Escherichia coli

Carré

Hamon

Ennahar

et al. 2014

Appl Environ Microbiol

200

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e This study investigates the mechanisms of UV-A (315 to 400 nm) photocatalysis with titanium dioxide (TiO 2 ) applied to the degradation of Escherichia coli and their effects on two key cellular components: lipids and proteins. The impact of TiO 2 photocatalysis on E. coli survival was monitored by counting on agar plate and by assessing lipid peroxidation and performing proteomic analysis. We observed through malondialdehyde quantification that lipid peroxidation occurred during the photocatalytic process, and the addition of superoxide dismutase, which acts as a scavenger of the superoxide anion radical (O 2 · ؊ ), inhibited this effect by half, showing us that O 2 · ؊ radicals participate in the photocatalytic antimicrobial effect. Qualitative analysis using twodimensional electrophoresis allowed selection of proteins for which spot modifications were observed during the applied treatments. Two-dimensional electrophoresis highlighted that among the selected protein spots, 7 and 19 spots had already disappeared in the dark in the presence of 0.1 g/liter and 0.4 g/liter TiO 2 , respectively, which is accounted for by the cytotoxic effect of TiO 2 . Exposure to 30 min of UV-A radiation in the presence of 0.1 g/liter and 0.4 g/liter TiO 2 increased the numbers of missing spots to 14 and 22, respectively. The proteins affected by photocatalytic oxidation were strongly heterogeneous in terms of location and functional category. We identified several porins, proteins implicated in stress response, in transport, and in bacterial metabolism. This study reveals the simultaneous effects of O 2 · ؊ on lipid peroxidation and on the proteome during photocatalytic treatment and therefore contributes to a better understanding of molecular mechanisms in antibacterial photocatalytic treatment.

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Section: Discussionmentioning

confidence: 99%

TiO ₂ Photocatalysis Damages Lipids and Proteins in Escherichia coli

Carré

Hamon

Ennahar

et al. 2014

Appl Environ Microbiol

200

View full text Add to dashboard Cite

show abstract

“…This variability in receptor-ligand interaction for effective phagocytosis extends to other bacterial species as well. Some outer membrane proteins, such as OmpA, in virulent strains of Escherichia coli and Klebsiella pneumoniae dictate recognition and internalization by macrophages (59, 141), but not necessarily neutrophils (45), and loss of the OmpA ortholog, OprF, in P. aeruginosa may affect both association with host cells and the ability of the bacteria to ultimately form a biofilm (38,75). Likewise, we recently showed that scavenger receptor A (SR-A) on mouse phagocytes is the major phagocytic receptor engaged by specific strains of ␥-proteobacteria (e.g., DH5␣ E. coli), but it is not singularly necessary for uptake of the parental strain K12 E. coli, nor is it needed for uptake of PA14 P. aeruginosa (3).…”

Section: Bacterial Invasion Vs Phagocytic Engulfmentmentioning

confidence: 99%

Mechanisms of phagocytosis and host clearance ofPseudomonas aeruginosa

Lovewell

Patankar

Berwin

2014

American Journal of Physiology-Lung Cellular and Molecular Phys

148

127

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domonas aeruginosa is an opportunistic bacterial pathogen responsible for a high incidence of acute and chronic pulmonary infection. These infections are particularly prevalent in patients with chronic obstructive pulmonary disease and cystic fibrosis: much of the morbidity and pathophysiology associated with these diseases is due to a hypersusceptibility to bacterial infection. Innate immunity, primarily through inflammatory cytokine production, cellular recruitment, and phagocytic clearance by neutrophils and macrophages, is the key to endogenous control of P. aeruginosa infection. In this review, we highlight recent advances toward understanding the innate immune response to P. aeruginosa, with a focus on the role of phagocytes in control of P. aeruginosa infection. Specifically, we summarize the cellular and molecular mechanisms of phagocytic recognition and uptake of P. aeruginosa, and how current animal models of P. aeruginosa infection reflect clinical observations in the context of phagocytic clearance of the bacteria. Several notable phenotypic changes to the bacteria are consistently observed during chronic pulmonary infections, including changes to mucoidy and flagellar motility, that likely enable or reflect their ability to persist. These traits are likewise examined in the context of how the bacteria avoid phagocytic clearance, inflammation, and sterilizing immunity.

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“…OmpA has multiple functions (reviewed in [2]) including its contribution to maintaining the outer membrane integrity [3] and Ffactor dependent bacterial conjugation [4][5][6]. In addition, OmpA can mediate virulence and pathogenicity of E. coli, and it has become an important target in the immune response (reviewed in [7]). It also acts as the receptor for several bacteriophages [8][9][10] and colicins [11,12].…”

Section: Introductionmentioning

confidence: 99%

The periplasmic domain of Escherichia coli outer membrane protein A can undergo a localized temperature dependent structural transition

Ishida

Garcı́a-Herrero

Vogel

2014

Biochimica et Biophysica Acta (BBA) - Biomembranes

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Gram-negative bacteria such as Escherichia coli are surrounded by two membranes with a thin peptidoglycan (PG)-layer located in between them in the periplasmic space. The outer membrane protein A (OmpA) is a 325-residue protein and it is the major protein component of the outer membrane of E. coli. Previous structure determinations have focused on the N-terminal fragment (residues 1-171) of OmpA, which forms an eight stranded transmembrane β-barrel in the outer membrane. Consequently it was suggested that OmpA is composed of two independently folded domains in which the N-terminal β-barrel traverses the outer membrane and the C-terminal domain (residues 180-325) adopts a folded structure in the periplasmic space. However, some reports have proposed that full-length OmpA can instead refold in a temperature dependent manner into a single domain forming a larger transmembrane pore. Here, we have determined the NMR solution structure of the C-terminal periplasmic domain of E. coli OmpA (OmpA(180-325)). Our structure reveals that the C-terminal domain folds independently into a stable globular structure that is homologous to the previously reported PG-associated domain of Neisseria meningitides RmpM. Our results lend credence to the two domain structure model and a PG-binding function for OmpA, and we could indeed localize the PG-binding site on the protein through NMR chemical shift perturbation experiments. On the other hand, we found no evidence for binding of OmpA(180-325) with the TonB protein. In addition, we have also expressed and purified full-length OmpA (OmpA(1-325)) to study the structure of the full-length protein in micelles and nanodiscs by NMR spectroscopy. In both membrane mimetic environments, the recombinant OmpA maintains its two domain structure that is connected through a flexible linker. A series of temperature-dependent HSQC experiments and relaxation dispersion NMR experiments detected structural destabilization in the bulge region of the periplasmic domain of OmpA above physiological temperatures, which may induce dimerization and play a role in triggering the previously reported larger pore formation.

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Outer membrane protein A and OprF: versatile roles in Gram‐negative bacterial infections

Cited by 118 publications

References 67 publications

TiO ₂ Photocatalysis Damages Lipids and Proteins in Escherichia coli

TiO ₂ Photocatalysis Damages Lipids and Proteins in Escherichia coli

Mechanisms of phagocytosis and host clearance ofPseudomonas aeruginosa

The periplasmic domain of Escherichia coli outer membrane protein A can undergo a localized temperature dependent structural transition

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Outer membrane protein A and OprF: versatile roles in Gram‐negative bacterial infections

Cited by 118 publications

References 67 publications

TiO 2 Photocatalysis Damages Lipids and Proteins in Escherichia coli

TiO 2 Photocatalysis Damages Lipids and Proteins in Escherichia coli

Mechanisms of phagocytosis and host clearance ofPseudomonas aeruginosa

The periplasmic domain of Escherichia coli outer membrane protein A can undergo a localized temperature dependent structural transition

Contact Info

Product

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TiO ₂ Photocatalysis Damages Lipids and Proteins in Escherichia coli

TiO ₂ Photocatalysis Damages Lipids and Proteins in Escherichia coli