scholarly journals The dynamics and pH-dependence of Ag43 adhesins’ self-association probed by atomic force spectroscopy

Nanoscale ◽  
2014 ◽  
Vol 6 (21) ◽  
pp. 12665-12681 ◽  
Author(s):  
Adrien Jacquot ◽  
Chizuko Sakamoto ◽  
Angelina Razafitianamarahavo ◽  
Céline Caillet ◽  
Jenny Merlin ◽  
...  
Keyword(s):  
Cell Surface ◽  
Biofilm Formation ◽  
Ph Dependence ◽  
Force Spectroscopy ◽  
Surface Proteins ◽  
Cell Surface Proteins ◽  
Atomic Force Spectroscopy ◽  
Atomic Force ◽  
Self Association

Self-associating auto-transporter (SAAT) adhesins are two-domain cell surface proteins involved in bacteria auto-aggregation and biofilm formation.

scholarly journals Extracellular DNA, cell surface proteins and c-di-GMP promote biofilm formation in Clostridioides difficile

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lisa F. Dawson ◽  
Johann Peltier ◽  
Catherine L. Hall ◽  
Mark A. Harrison ◽  
Maria Derakhshan ◽  
...  
Keyword(s):  
Cell Surface ◽  
Biofilm Formation ◽  
Bacterial Species ◽  
Surface Proteins ◽  
Extracellular Dna ◽  
Cell Surface Proteins ◽  
Secondary Messenger ◽  
Clostridioides Difficile ◽  
Antibiotic Efficacy ◽  
Biofilm Matrix

AbstractClostridioides difficile is the leading cause of nosocomial antibiotic-associated diarrhoea worldwide, yet there is little insight into intestinal tract colonisation and relapse. In many bacterial species, the secondary messenger cyclic-di-GMP mediates switching between planktonic phase, sessile growth and biofilm formation. We demonstrate that c-di-GMP promotes early biofilm formation in C. difficile and that four cell surface proteins contribute to biofilm formation, including two c-di-GMP regulated; CD2831 and CD3246, and two c-di-GMP-independent; CD3392 and CD0183. We demonstrate that C. difficile biofilms are composed of extracellular DNA (eDNA), cell surface and intracellular proteins, which form a protective matrix around C. difficile vegetative cells and spores, as shown by a protective effect against the antibiotic vancomycin. We demonstrate a positive correlation between biofilm biomass, sporulation frequency and eDNA abundance in all five C. difficile lineages. Strains 630 (RT012), CD305 (RT023) and M120 (RT078) contain significantly more eDNA in their biofilm matrix than strains R20291 (RT027) and M68 (RT017). DNase has a profound effect on biofilm integrity, resulting in complete disassembly of the biofilm matrix, inhibition of biofilm formation and reduced spore germination. The addition of exogenous DNase could be exploited in treatment of C. difficile infection and relapse, to improve antibiotic efficacy.

scholarly journals Role of SrtA in Pathogenicity of Staphylococcus lugdunensis

2020 ◽  
Vol 8 (12) ◽  
pp. 1975
Author(s):  
Muzaffar Hussain ◽  
Christian Kohler ◽  
Karsten Becker
Keyword(s):  
Cell Wall ◽  
Cell Surface ◽  
Biofilm Formation ◽  
Surface Proteins ◽  
Transcription Level ◽  
Coagulase Negative Staphylococci ◽  
Staphylococcus Lugdunensis ◽  
Cell Surface Proteins ◽  
Mutant Strains

Among coagulase-negative staphylococci (CoNS), Staphylococcus lugdunensis has a special position as causative agent of aggressive courses of infectious endocarditis (IE) more reminiscent of IEs caused by Staphylococcus aureus than those by CoNS. To initiate colonization and invasion, bacterial cell surface proteins are required; however, only little is known about adhesion of S. lugdunensis to biotic surfaces. Cell surface proteins containing the LPXTG anchor motif are covalently attached to the cell wall by sortases. Here, we report the functionality of Staphylococcus lugdunensis sortase A (SrtA) to link LPXTG substrates to the cell wall. To determine the role of SrtA dependent surface proteins in biofilm formation and binding eukaryotic cells, we generated SrtA-deficient mutants (ΔsrtA). These mutants formed a smaller amount of biofilm and bound less to immobilized fibronectin, fibrinogen, and vitronectin. Furthermore, SrtA absence affected the gene expression of two different adhesins on transcription level. Surprisingly, we found no decreased adherence and invasion in human cell lines, probably caused by the upregulation of further adhesins in ΔsrtA mutant strains. In conclusion, the functionality of S. lugdunensis SrtA in anchoring LPXTG substrates to the cell wall let us define it as the pathogen’s housekeeping sortase.

What do nanometer molecular trajectories tell us about heterogeneous cell surface domaines?

1995 ◽  
Vol 53 ◽  
pp. 786-787
Author(s):  
Watt W. Webb
Keyword(s):  
Cell Surface ◽  
Lipid Membranes ◽  
Surface Proteins ◽  
Protein Diffusion ◽  
Coated Pits ◽  
Cell Surface Proteins ◽  
Membrane Heterogeneity ◽  
Fluorescence Photobleaching Recovery ◽  
Photobleaching Recovery ◽  
Plasma Membrane Heterogeneity

Plasma membrane heterogeneity is implicit in the existence of specialized cell surface organelles which are necessary for cellular function; coated pits, post and pre-synaptic terminals, microvillae, caveolae, tight junctions, focal contacts and endothelial polarization are examples. The persistence of these discrete molecular aggregates depends on localized restraint of the constituent molecules within specific domaines in the cell surface by strong intermolecular bonds and/or anchorage to extended cytoskeleton. The observed plasticity of many of organelles and the dynamical modulation of domaines induced by cellular signaling evidence evanescent intermolecular interactions even in conspicuous aggregates. There is also strong evidence that universal restraints on the mobility of cell surface proteins persist virtually everywhere in cell surfaces, not only in the discrete organelles. Diffusion of cell surface proteins is slowed by several orders of magnitude relative to corresponding protein diffusion coefficients in isolated lipid membranes as has been determined by various ensemble average methods of measurement such as fluorescence photobleaching recovery(FPR).

Dysfunction of endothelial cells exposed to nanomaterials assessed by atomic force spectroscopy

Micron ◽  
2021 ◽  
Vol 145 ◽  
pp. 103062
Author(s):  
Agnieszka Maria Kolodziejczyk ◽  
Paulina Sokolowska ◽  
Aleksandra Zimon ◽  
Magdalena Grala ◽  
Marcin Rosowski ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Force Spectroscopy ◽  
Atomic Force Spectroscopy ◽  
Atomic Force

scholarly journals Cell Surface Expression of Nrg1 Protein in Candida auris

2021 ◽  
Vol 7 (4) ◽  
pp. 262
Author(s):  
Anuja Paudyal ◽  
Govindsamy Vediyappan
Keyword(s):  
Cell Surface ◽  
Growth Conditions ◽  
Zinc Ion ◽  
Surface Proteins ◽  
Cell Surface Expression ◽  
Unexpected Finding ◽  
Candida Auris ◽  
Cell Surface Proteins ◽  
Biofilm Growth

Candida auris is an emerging antifungal resistant human fungal pathogen increasingly reported in healthcare facilities. It persists in hospital environments, and on skin surfaces, and can form biofilms readily. Here, we investigated the cell surface proteins from C. auris biofilms grown in a synthetic sweat medium mimicking human skin conditions. Cell surface proteins from both biofilm and planktonic control cells were extracted with a buffer containing β-mercaptoethanol and resolved by 2-D gel electrophoresis. Some of the differentially expressed proteins were excised and identified by mass spectrometry. C. albicans orthologs Spe3p, Tdh3p, Sod2p, Ywp1p, and Mdh1p were overexpressed in biofilm cells when compared to the planktonic cells of C. auris. Interestingly, several proteins with zinc ion binding activity were detected. Nrg1p is a zinc-binding transcription factor that negatively regulates hyphal growth in C. albicans. C. auris does not produce true hypha under standard in vitro growth conditions, and the role of Nrg1p in C. auris is currently unknown. Western blot analyses of cell surface and cytosolic proteins of C. auris against anti-CalNrg1 antibody revealed the Nrg1p in both locations. Cell surface localization of Nrg1p in C. auris, an unexpected finding, was further confirmed by immunofluorescence microscopy. Nrg1p expression is uniform across all four clades of C. auris and is dependent on growth conditions. Taken together, the data indicate that C. auris produces several unique proteins during its biofilm growth, which may assist in the skin-colonizing lifestyle of the fungus during its pathogenesis.

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