Cell-Associated Pheromone Peptide (cCF10) Production and Pheromone Inhibition in Enterococcus faecalis

ABSTRACT In Enterococcus faecalis, the peptide cCF10 acts as a pheromone, inducing transfer of the conjugative plasmid pCF10 from plasmid-containing donor cells to plasmid-free recipient cells. In these studies, it was found that a substantial amount of cCF10 associates with the envelope of the producing cell. Pheromone activity was detected in both wall and membrane fractions, with the highest activity associated with the wall. Experiments examining the effects of protease inhibitor treatments either prior to or following cell fractionation suggested the presence of a cell envelope-associated pro-cCF10 that can be processed to mature cCF10 by a maturase or protease. A pCF10-encoded membrane protein, PrgY, was shown to prevent self-induction of donor cells by reducing the level of pheromone activity in the cell wall fraction.

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Putative Surface Proteins Encoded within a Novel Transferable Locus Confer a High-Biofilm Phenotype to Enterococcus faecalis

Journal of Bacteriology ◽

10.1128/jb.188.6.2063-2072.2006 ◽

2006 ◽

Vol 188 (6) ◽

pp. 2063-2072 ◽

Cited By ~ 66

Author(s):

Preeti M. Tendolkar ◽

Arto S. Baghdayan ◽

Nathan Shankar

Keyword(s):

Cell Wall ◽

Enterococcus Faecalis ◽

Insertional Mutagenesis ◽

Surface Proteins ◽

Conjugative Plasmid ◽

Sequence Information ◽

Wild Type ◽

Abiotic Surfaces ◽

Mutant Bank

ABSTRACT Enterococci are opportunistic pathogens and among the leading causes of nosocomial infections. Enterococcus faecalis, the dominant species among infection-derived isolates, has recently been recognized as capable of forming biofilms on abiotic surfaces in vitro as well as on indwelling medical devices. A few bacterial factors known to contribute to biofilm formation in E. faecalis have been characterized. To identify additional factors which may be important to this process, we utilized a Tn917-based insertional mutagenesis strategy to generate a mutant bank in a high-biofilm-forming E. faecalis strain, E99. The resulting mutant bank was screened for mutants exhibiting a significantly reduced ability to form biofilms. One mutant, P101D12, which showed greater than 70% reduction in its ability to form biofilms compared to the wild-type parent, was further characterized. The single Tn917 insertion in P101D12 was mapped to a gene, bee-2, encoding a probable cell wall-anchored protein. Sequence information for the region flanking bee-2 revealed that this gene was a member of a locus (termed the bee locus for biofilm enhancer in enterococcus) comprised of five genes encoding three putative cell wall-anchored proteins and two probable sortases. Contour-clamped homogeneous electric field gel and Southern hybridization analyses suggested that the bee locus is likely harbored on a large conjugative plasmid. Filter mating assays using wild-type E99 or mutant P101D12 as a donor confirmed that the bee locus could transfer conjugally at high frequency to recipient E. faecalis strains. This represents the first instance of the identification of a mobile genetic element conferring biofilm-forming property in E. faecalis.

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L-form bacteria, cell walls and the origins of life

Open Biology ◽

10.1098/rsob.120143 ◽

2013 ◽

Vol 3 (1) ◽

pp. 120143 ◽

Cited By ~ 112

Author(s):

Jeff Errington

Keyword(s):

Cell Wall ◽

Cell Envelope ◽

Evolutionary Development ◽

Last Common Ancestor ◽

Bacterial Cells ◽

A Cell ◽

Evolutionary Radiations ◽

Key Steps ◽

Bacterial Domain

The peptidoglycan wall is a defining feature of bacterial cells and was probably already present in their last common ancestor. L-forms are bacterial variants that lack a cell wall and divide by a variety of processes involving membrane blebbing, tubulation, vesiculation and fission. Their unusual mode of proliferation provides a model for primitive cells and is reminiscent of recently developed in vitro vesicle reproduction processes. Invention of the cell wall may have underpinned the explosion of bacterial life on the Earth. Later innovations in cell envelope structure, particularly the emergence of the outer membrane of Gram-negative bacteria, possibly in an early endospore former, seem to have spurned further major evolutionary radiations. Comparative studies of bacterial cell envelope structure may help to resolve the early key steps in evolutionary development of the bacterial domain of life.

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Mutations in the Lipopolysaccharide Biosynthesis Pathway Interfere with Crescentin-Mediated Cell Curvature in Caulobacter crescentus

Journal of Bacteriology ◽

10.1128/jb.01371-09 ◽

2010 ◽

Vol 192 (13) ◽

pp. 3368-3378 ◽

Cited By ~ 23

Author(s):

Matthew T. Cabeen ◽

Michelle A. Murolo ◽

Ariane Briegel ◽

N. Khai Bui ◽

Waldemar Vollmer ◽

...

Keyword(s):

Cell Wall ◽

Caulobacter Crescentus ◽

Cell Envelope ◽

Cellular Systems ◽

Biosynthesis Pathway ◽

Cell Morphogenesis ◽

Division Site ◽

Growth Properties ◽

A Cell ◽

Cellular Components

ABSTRACT Bacterial cell morphogenesis requires coordination among multiple cellular systems, including the bacterial cytoskeleton and the cell wall. In the vibrioid bacterium Caulobacter crescentus, the intermediate filament-like protein crescentin forms a cell envelope-associated cytoskeletal structure that controls cell wall growth to generate cell curvature. We undertook a genetic screen to find other cellular components important for cell curvature. Here we report that deletion of a gene (wbqL) involved in the lipopolysaccharide (LPS) biosynthesis pathway abolishes cell curvature. Loss of WbqL function leads to the accumulation of an aberrant O-polysaccharide species and to the release of the S layer in the culture medium. Epistasis and microscopy experiments show that neither S-layer nor O-polysaccharide production is required for curved cell morphology per se but that production of the altered O-polysaccharide species abolishes cell curvature by apparently interfering with the ability of the crescentin structure to associate with the cell envelope. Our data suggest that perturbations in a cellular pathway that is itself fully dispensable for cell curvature can cause a disruption of cell morphogenesis, highlighting the delicate harmony among unrelated cellular systems. Using the wbqL mutant, we also show that the normal assembly and growth properties of the crescentin structure are independent of its association with the cell envelope. However, this envelope association is important for facilitating the local disruption of the stable crescentin structure at the division site during cytokinesis.

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A cell wall damage response mediated by a sensor kinase/response regulator pair enables beta-lactam tolerance

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1520333113 ◽

2015 ◽

Vol 113 (2) ◽

pp. 404-409 ◽

Cited By ~ 34

Author(s):

Tobias Dörr ◽

Laura Alvarez ◽

Fernanda Delgado ◽

Brigid M. Davis ◽

Felipe Cava ◽

...

Keyword(s):

Cell Wall ◽

Response Regulator ◽

Cell Envelope ◽

Normal Growth ◽

Cell Diameter ◽

Cell Wall Synthesis ◽

Beta Lactam ◽

Cell Wall Damage ◽

A Cell

The bacterial cell wall is critical for maintenance of cell shape and survival. Following exposure to antibiotics that target enzymes required for cell wall synthesis, bacteria typically lyse. Although several cell envelope stress response systems have been well described, there is little knowledge of systems that modulate cell wall synthesis in response to cell wall damage, particularly in Gram-negative bacteria. Here we describe WigK/WigR, a histidine kinase/response regulator pair that enablesVibrio cholerae, the cholera pathogen, to survive exposure to antibiotics targeting cell wall synthesis in vitro and during infection. Unlike wild-typeV. cholerae, mutants lackingwigRfail to recover following exposure to cell-wall–acting antibiotics, and they exhibit a drastically increased cell diameter in the absence of such antibiotics. Conversely, overexpression ofwigRleads to cell slimming. Overexpression of activated WigR also results in increased expression of the full set of cell wall synthesis genes and to elevated cell wall content. WigKR-dependent expression of cell wall synthesis genes is induced by various cell-wall–acting antibiotics as well as by overexpression of an endogenous cell wall hydrolase. Thus, WigKR appears to monitor cell wall integrity and to enhance the capacity for increased cell wall production in response to damage. Taken together, these findings implicate WigKR as a regulator of cell wall synthesis that controls cell wall homeostasis in response to antibiotics and likely during normal growth as well.

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Identification of Proteins from a Cell Wall Fraction of the DiatomThalassiosira pseudonana

Molecular & Cellular Proteomics ◽

10.1074/mcp.m500174-mcp200 ◽

2005 ◽

Vol 5 (1) ◽

pp. 182-193 ◽

Cited By ~ 89

Author(s):

Luciano G. Frigeri ◽

Timothy R. Radabaugh ◽

Paul A. Haynes ◽

Mark Hildebrand

Keyword(s):

Cell Wall ◽

Cell Wall Fraction ◽

A Cell

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The outer layer of the cell envelope of Halobacterium halobium

Canadian Journal of Biochemistry ◽

10.1139/o69-013 ◽

1969 ◽

Vol 47 (1) ◽

pp. 71-74 ◽

Cited By ~ 6

Author(s):

Carolyn L. Marshall ◽

A. J. Wicken ◽

A. D. Brown

Keyword(s):

Cell Wall ◽

Chemical Analysis ◽

Outer Layer ◽

Bacterial Cell ◽

Cell Walls ◽

Cell Envelope ◽

Halobacterium Halobium ◽

A Cell ◽

Bacterial Cell Walls

The outer layer of the cell envelope of Halobacterium halobium was isolated after suspending the envelope in either 1 M NaCl or 0.02 M MgCl2. Chemical analysis of the isolated, solubilized outer layer showed it to consist of protein or glycoprotein with about 3% RNA. No free or bound lipid was detected. No cytochromes were present in the outer layer. Components commonly associated with bacterial cell walls were absent.Chemical composition together with the marked instability of the outer layer in a slight ion deficit are not consistent with a function of this layer as a "cell wall" of the organism.

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Inroads through the bacterial cell envelope: seeing is believing

Canadian Journal of Microbiology ◽

10.1139/cjm-2018-0091 ◽

2018 ◽

Vol 64 (9) ◽

pp. 601-617 ◽

Cited By ~ 3

Author(s):

Cezar M. Khursigara ◽

Susan F. Koval ◽

Dianne M. Moyles ◽

Robert J. Harris

Keyword(s):

Electron Microscopy ◽

Bacterial Cell ◽

Caulobacter Crescentus ◽

Cell Envelope ◽

Cell Fractionation ◽

Doctoral Studies ◽

Cryo Electron Microscopy ◽

A Cell ◽

Cell Envelopes ◽

Microscopy Techniques

A singular feature of all prokaryotic cells is the presence of a cell envelope composed of a cytoplasmic membrane and a cell wall. The introduction of bacterial cell fractionation techniques in the 1950s and 1960s along with developments in procedures for electron microscopy opened the window towards an understanding of the chemical composition and architecture of the cell envelope. This review traces the contribution of Terry Beveridge in these endeavours, beginning with his doctoral studies in the 1970s on the structure of paracrystalline surface arrays (S-layers), followed by an exploration of cryogenic methods for preserving bacteria for ultrastructural analyses. His insights are reflected in a current example of the contribution of cryo-electron microscopy to S-layer studies — the structure and assembly of the surface array of Caulobacter crescentus. The review then focuses on Terry’s contributions to imaging the ultrastructure of bacterial cell envelopes and to the development of cryo-electron microscopy techniques, including the use of CEMOVIS (Cryo-electron Microscopy of Vitreous Sections) to “see” the ultrastructure of the Gram-positive cell envelope — his last scientific endeavour.

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