scholarly journals MapA, a second large RTX adhesin, contributes to biofilm formation by Pseudomonas fluorescens

2020 ◽  
Author(s):  
Alan J. Collins ◽  
Alexander B. Pastora ◽  
T. Jarrod Smith ◽  
Kurt Dahlstrom ◽  
George A. O’Toole
Keyword(s):  
Biofilm Formation ◽  
Specific Growth ◽  
Growth Conditions ◽  
Bacterial Biofilms ◽  
Effector Protein ◽  
Standard Laboratory ◽  
Bacterial Adhesins ◽  
A Cell ◽  
Membrane Spanning

AbstractMechanisms by which cells attach to a surface and form a biofilm are diverse and differ greatly between organisms. The Gram-negative, Gammaproteobacterium Pseudomonas fluorescens attaches to a surface through the localization of the large type 1-secreted RTX adhesin LapA to the outer surface of the cell. LapA localization to the cell surface is controlled by the activities of a periplasmic protease, LapG and an inner-membrane spanning cyclic di-GMP responsive effector protein, LapD. A previous study identified a second, LapA-like protein encoded in the P. fluorescens Pf0-1 genome: Pfl01_1463. However, deletion of this gene had no discernible phenotype under our standard laboratory growth conditions. Here, we identified specific growth conditions wherein, Pfl01_1463, hereafter called MapA (Medium Adhesion Protein A) is a functional adhesin contributing to biofilm formation. This adhesin, like LapA, appears to be secreted through a Lap-related type 1 secretion machinery. We show MapA involvement in biofilm formation is also controlled by LapD and LapG, and that the differing roles of LapA and MapA in biofilm formation are achieved, at least in part, through the differences in the sequences of the two adhesins and their differential, cyclic di-GMP-dependent transcriptional regulation. This differential regulation appears to lead to different distributions of the expression of lapA and mapA within a biofilm. Our data indicate that the mechanisms by which a cell forms a biofilm and the components of a biofilm matrix can differ depending on growth conditions in the biofilm.ImportanceAdhesins are critical for the formation and maturation of bacterial biofilms. We identify a second adhesin in P. fluorescens, called MapA, which appears to play a role in biofilm maturation and whose regulation is distinct from the previously reported LapA adhesin, which is critical for biofilm initiation. Analysis of bacterial adhesins show that LapA-like and MapA-like adhesins are found broadly in Pseudomonads and related organisms, indicating that the utilization of different suites of adhesins may be broadly important in the Gammaproteobacteria.

scholarly journals MapA, a Second Large RTX Adhesin Conserved across the Pseudomonads, Contributes to Biofilm Formation by Pseudomonas fluorescens

2020 ◽  
Vol 202 (18) ◽  
Author(s):  
Alan J. Collins ◽  
Alexander B. Pastora ◽  
T. Jarrod Smith ◽  
George A. O’Toole
Keyword(s):  
Pseudomonas Fluorescens ◽  
Biofilm Formation ◽  
Matrix Protein ◽  
Protein S ◽  
Growth Conditions ◽  
Content Type ◽  
The Matrix ◽  
A Cell ◽  
Membrane Spanning

ABSTRACT Mechanisms by which cells attach to a surface and form a biofilm are diverse and differ greatly among organisms. The Gram-negative gammaproteobacterium Pseudomonas fluorescens attaches to a surface through the localization of the large type 1-secreted RTX adhesin LapA to the outer surface of the cell. LapA localization to the cell surface is controlled by the activities of a periplasmic protease, LapG, and an inner membrane-spanning cyclic di-GMP-responsive effector protein, LapD. A previous study identified a second, LapA-like protein encoded in the P. fluorescens Pf0-1 genome: Pfl01_1463. Here, we identified specific growth conditions under which Pfl01_1463, here called MapA (medium adhesion protein A) is a functional adhesin contributing to biofilm formation. This adhesin, like LapA, appears to be secreted through a Lap-related type 1 secretion machinery, and its localization is controlled by LapD and LapG. However, differing roles of LapA and MapA in biofilm formation are achieved, at least in part, through the differences in the sequences of the two adhesins and different distributions of the expression of the lapA and mapA genes within a biofilm. LapA-like proteins are broadly distributed throughout the Proteobacteria, and furthermore, LapA and MapA are well conserved among other Pseudomonas species. Together, our data indicate that the mechanisms by which a cell forms a biofilm and the components of a biofilm matrix can differ depending on growth conditions and the matrix protein(s) expressed. IMPORTANCE Adhesins are critical for the formation and maturation of bacterial biofilms. We identify a second adhesin in P. fluorescens, called MapA, which appears to play a role in biofilm maturation and whose regulation is distinct from the previously reported LapA adhesin, which is critical for biofilm initiation. Analysis of bacterial adhesins shows that LapA-like and MapA-like adhesins are found broadly in pseudomonads and related organisms, indicating that the utilization of different suites of adhesins may be broadly important in the Gammaproteobacteria.

scholarly journals Role of the Streptococcus mutans irvA Gene in GbpC-Independent, Dextran-Dependent Aggregation and Biofilm Formation

2009 ◽  
Vol 75 (22) ◽  
pp. 7037-7043 ◽  
Author(s):  
Min Zhu ◽  
Dragana Ajdić ◽  
Yuan Liu ◽  
David Lynch ◽  
Justin Merritt ◽  
...  
Keyword(s):  
Streptococcus Mutans ◽  
Biofilm Formation ◽  
Growth Conditions ◽  
Parental Background ◽  
A Cell ◽  
Major Surface ◽  
Biofilm Development ◽  
Small Aggregation

ABSTRACT Dextran-dependent aggregation (DDAG) of Streptococcus mutans is an in vitro phenomenon that is believed to represent a property of the organism that is beneficial for sucrose-dependent biofilm development. GbpC, a cell surface glucan-binding protein, is responsible for DDAG in S. mutans when cultured under defined stressful conditions. Recent reports have described a putative transcriptional regulator gene, irvA, located just upstream of gbpC, that is normally repressed by the product of an adjacent gene, irvR. When repression of irvA is relieved, there is a resulting increase in the expression of GbpC and decreases in competence and synthesis of the antibiotic mutacin I. This study examined the role of irvA in DDAG and biofilm formation by engineering strains that overexpressed irvA (IrvA+) on an extrachromosomal plasmid. The IrvA+ strain displayed large aggregation particles that did not require stressful growth conditions. A novel finding was that overexpression of irvA in a gbpC mutant background retained a measure of DDAG, albeit very small aggregation particles. Biofilms formed by the IrvA+ strain in the parental background possessed larger-than-normal microcolonies. In a gbpC mutant background, the overexpression of irvA reversed the fragile biofilm phenotype normally associated with loss of GbpC. Real-time PCR and Northern blot analyses found that expression of gbpC did not change significantly in the IrvA+ strain but expression of spaP, encoding the major surface adhesin P1, increased significantly. Inactivation of spaP eliminated the small-particle DDAG. The results suggest that IrvA promotes DDAG not only by GbpC, but also via an increase in P1.

scholarly journals Inkjet based 3D Printing of bespoke medical devices that resist bacterial biofilm formation

2020 ◽  
Author(s):  
Yinfeng He ◽  
Belen Begines ◽  
Jeni Luckett ◽  
Jean-Frédéric Dubern ◽  
Andrew L. Hook ◽  
...  
Keyword(s):  
3D Printing ◽  
Cell Fate ◽  
Biofilm Formation ◽  
Bacterial Attachment ◽  
Bacterial Biofilm ◽  
Bacterial Biofilms ◽  
Printing Inks ◽  
A Cell ◽  
3D Printed

AbstractWe demonstrate the formulation of advanced functional 3D printing inks that prevent the formation of bacterial biofilms in vivo. Starting from polymer libraries, we show that a biofilm resistant object can be 3D printed with the potential for shape and cell instructive function to be selected independently. When tested in vivo, the candidate materials not only resisted bacterial attachment but drove the recruitment of host defences in order to clear infection. To exemplify our approach, we manufacture a finger prosthetic and demonstrate that it resists biofilm formation – a cell instructive function that can prevent the development of infection during surgical implantation. More widely, cell instructive behaviours can be ‘dialled up’ from available libraries and may include in the future such diverse functions as the modulation of immune response and the direction of stem cell fate.

Polycystin expression is temporally and spatially regulated during renal development

1997 ◽  
Vol 272 (5) ◽  
pp. F602-F609 ◽  
Author(s):  
J. Van Adelsberg ◽  
S. Chamberlain ◽  
V. D'Agati
Keyword(s):  
Plasma Membranes ◽  
Predicted Amino Acid Sequence ◽  
Renal Development ◽  
Polycystic Kidney ◽  
Fetal Kidney ◽  
Spatial Regulation ◽  
Adult Kidney ◽  
A Cell ◽  
Autosomal Dominant Polycystic Kidney ◽  
Membrane Spanning

Mutations in PKD1 cause autosomal dominant polycystic kidney disease (ADPKD), a common genetic disease in which cysts form from kidney tubules. The predicted product of this gene is a novel protein with cell-adhesive and membrane-spanning domains. To test the hypothesis that polycystin, the product of the PKD1 gene, is a cell adhesion molecule, we raised antibodies against peptides derived from the unduplicated, membrane-spanning portion of the predicted amino acid sequence. These antibodies recognized membrane-associated polypeptides of 485 and 245 kDa in human fetal kidney homogenates. Expression was greater in fetal than adult kidney by both Western blot analysis and immunofluorescence. In fetal kidney, polycystin was localized to the plasma membranes of ureteric bud and comma and S-shaped bodies. However, in more mature tubules in fetal kidney, in adult kidney, and in polycystic kidney, the majority of polycystin staining was intracellular. The temporal and spatial regulation of polycystin expression during renal development lead us to speculate that polycystin may play a role in nephrogenesis.

Glycans in scaffold design in tissue reconstruction

2021 ◽  
pp. 088391152199784
Author(s):  
Nipun Jain ◽  
Shashi Singh
Keyword(s):  
Cell Attachment ◽  
Low Cost ◽  
Growth Conditions ◽  
Downstream Signaling ◽  
Cell Carrier ◽  
Wide Range ◽  
Proliferation And Differentiation ◽  
Different Types ◽  
Tissue Reconstruction ◽  
A Cell

Development of an artificial tissue by tissue engineering is witnessed to be one of the long lasting clarified solutions for the damaged tissue function restoration. To accomplish this, a scaffold is designed as a cell carrier in which the extracellular matrix (ECM) performs a prominent task of controlling the inoculated cell’s destiny. ECM composition, topography and mechanical properties lead to different types of interactions between cells and ECM components that trigger an assortment of cellular reactions via diverse sensing mechanisms and downstream signaling pathways. The polysaccharides in the form of proteoglycans and glycoproteins yield better outcomes when included in the designed matrices. Glycosaminoglycan (GAG) chains present on proteoglycans show a wide range of operations such as sequestering of critical effector morphogens which encourage proficient nutrient contribution toward the growing stem cells for their development and endurance. In this review we discuss how the glycosylation aspects are of considerable importance in everyday housekeeping functions of a cell especially when placed in a controlled environment under ideal growth conditions. Hydrogels made from these GAG chains have been used extensively as a resorbable material that mimics the natural ECM functions for an efficient control over cell attachment, permeability, viability, proliferation, and differentiation processes. Also the incorporation of non-mammalian polysaccharides can elicit specific receptor responses which authorize the creation of numerous vigorous frameworks while prolonging the low cost and immunogenicity of the substance.

scholarly journals Anaerobic Conditions Induce Expression of Polysaccharide Intercellular Adhesin in Staphylococcus aureus and Staphylococcus epidermidis

2001 ◽  
Vol 69 (6) ◽  
pp. 4079-4085 ◽  
Author(s):  
Sarah E. Cramton ◽  
Martina Ulrich ◽  
Friedrich Götz ◽  
Gerd Döring
Keyword(s):  
Staphylococcus Aureus ◽  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Extracellular Polysaccharide ◽  
Growth Conditions ◽  
Anaerobic Conditions ◽  
Anaerobic Environment ◽  
Specific Mrna

ABSTRACT Products of the intercellular adhesion (ica) operon in Staphylococcus aureus and Staphylococcus epidermidis synthesize a linear β-1,6-linked glucosaminylglycan. This extracellular polysaccharide mediates bacterial cell-cell adhesion and is required for biofilm formation, which is thought to increase the virulence of both pathogens in association with prosthetic biomedical implants. The environmental signal(s) that triggers ica gene product and polysaccharide expression is unknown. Here we demonstrate that anaerobic in vitro growth conditions lead to increased polysaccharide expression in both S. aureus and S. epidermidis, although the regulation is less stringent inS. epidermidis. Anaerobiosis also dramatically stimulates ica-specific mRNA expression inica- and polysaccharide-positive strains of both S. aureus and S. epidermidis.These data suggest a mechanism whereby ica gene expression and polysaccharide production may act as a virulence factor in an anaerobic environment in vivo.

Neurofibromin can inhibit Ras-dependent growth by a mechanism independent of its GTPase-accelerating function

1994 ◽  
Vol 14 (1) ◽  
pp. 641-645
Author(s):  
M R Johnson ◽  
J E DeClue ◽  
S Felzmann ◽  
W C Vass ◽  
G Xu ◽  
...  
Keyword(s):  
Tumor Suppressor ◽  
Tumor Suppressor Gene ◽  
Suppressor Gene ◽  
Protein Product ◽  
Growth Inhibitory ◽  
Nf1 Gene ◽  
A Cell ◽  
Dependent Growth ◽  
Nih 3T3

The NF1 gene, which is altered in patients with type 1 neurofibromatosis, has been postulated to function as a tumor suppressor gene. The NF1 protein product neurofibromin stimulates the intrinsic GTPase activity of active GTP-bound Ras, thereby inactivating it. Consistent with a tumor suppressor function, we have found that the introduction of NF1 in melanoma cell lines that are deficient in neurofibromin inhibited their growth and induced their differentiation. In addition, overexpression of neurofibromin in NIH 3T3 cells was growth inhibitory but did not alter the level of GTP.Ras in the cells. Transformation by v-ras, whose protein product is resistant to GTPase stimulation by neurofibromin, was inhibited in a cell line overexpressing neurofibromin, while transformation by v-raf was not altered. The results demonstrate that NF1 is a tumor suppressor gene that can inhibit Ras-dependent growth by a regulatory mechanism that is independent of neurofibromin's ability to stimulate Ras GTPase.

scholarly journals Nutritionally variant streptococci.

1991 ◽  
Vol 4 (2) ◽  
pp. 184-190 ◽  
Author(s):  
K L Ruoff
Keyword(s):  
Cell Wall ◽  
Oral Cavity ◽  
Successful Treatment ◽  
Distinct Species ◽  
Growth Conditions ◽  
Clinical Specimens ◽  
Wide Range ◽  
Streptococcal Species ◽  
A Cell

Streptococci requiring either pyridoxal or L-cysteine for growth were first observed 30 years ago as organisms forming satellite colonies adjacent to colonies of "helper" bacteria. Although they were previously considered nutritional mutants of viridans streptococcal species, the nutritionally variant streptococci (NVS) are currently thought to belong to distinct species of the genus Streptococcus. NVS strains may display pleomorphic cellular morphologies, depending on their growth conditions, and are distinguished from most other streptococci by enzymatic and serological characteristics and the presence of a cell wall chromophore. NVS are found as normal inhabitants of the oral cavity, and in addition to their participation in endocarditis, they have been isolated from a wide range of clinical specimens. Endocarditis caused by NVS is often difficult to eradicate; combinations of penicillin and an aminoglycoside are recommended for treatment. The unique physiological features of the NVS contribute to the difficulties encountered in their recovery from clinical specimens and may play a role in the problems associated with successful treatment of NVS endocarditis.

scholarly journals YdgG (TqsA) Controls Biofilm Formation in Escherichia coli K-12 through Autoinducer 2 Transport

2006 ◽  
Vol 188 (2) ◽  
pp. 587-598 ◽  
Author(s):  
Moshe Herzberg ◽  
Ian K. Kaye ◽  
Wolfgang Peti ◽  
Thomas K. Wood
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Acid Production ◽  
Polysialic Acid ◽  
Fold Increase ◽  
Uncharacterized Protein ◽  
Biofilm Thickness ◽  
Autoinducer 2 ◽  
Membrane Spanning ◽  
K 12

ABSTRACT YdgG is an uncharacterized protein that is induced in Escherichia coli biofilms. Here it is shown that deletion of ydgG decreased extracellular and increased intracellular concentrations of autoinducer 2 (AI-2); hence, YdgG enhances transport of AI-2. Consistent with this hypothesis, deletion of ydgG resulted in a 7,000-fold increase in biofilm thickness and 574-fold increase in biomass in flow cells. Also consistent with the hypothesis, deletion of ydgG increased cell motility by increasing transcription of flagellar genes (genes induced by AI-2). By expressing ydgG in trans, the wild-type phenotypes for extracellular AI-2 activity, motility, and biofilm formation were restored. YdgG is also predicted to be a membrane-spanning protein that is conserved in many bacteria, and it influences resistance to several antimicrobials, including crystal violet and streptomycin (this phenotype could also be complemented). Deletion of ydgG also caused 31% of the bacterial chromosome to be differentially expressed in biofilms, as expected, since AI-2 controls hundreds of genes. YdgG was found to negatively modulate expression of flagellum- and motility-related genes, as well as other known products essential for biofilm formation, including operons for type 1 fimbriae, autotransporter protein Ag43, curli production, colanic acid production, and production of polysaccharide adhesin. Eighty genes not previously related to biofilm formation were also identified, including those that encode transport proteins (yihN and yihP), polysialic acid production (gutM and gutQ), CP4-57 prophage functions (yfjR and alpA), methionine biosynthesis (metR), biotin and thiamine biosynthesis (bioF and thiDFH), anaerobic metabolism (focB, hyfACDR, ttdA, and fumB), and proteins with unknown function (ybfG, yceO, yjhQ, and yjbE); 10 of these genes were verified through mutation to decrease biofilm formation by 40% or more (yfjR, bioF, yccW, yjbE, yceO, ttdA, fumB, yjiP, gutQ, and yihR). Hence, it appears YdgG controls the transport of the quorum-sensing signal AI-2, and so we suggest the gene name tqsA.

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