scholarly journals Evolutionary flexibility in routes to mat formation by Pseudomonas

2021 ◽  
Author(s):  
Anuradha Mukherjee ◽  
Jenna Gallie
Keyword(s):  
Pseudomonas Fluorescens ◽  
Liquid Interface ◽  
Secondary Messenger ◽  
Diguanylate Cyclases ◽  
Close Relatives ◽  
High Level ◽  
Air Liquid Interface ◽  
Gmp Production

Many bacteria form mats at the air-liquid interface of static microcosms. These structures typically involve the secretion of exopolysaccharide(s), the production of which is often controlled by the secondary messenger c-di-GMP. Mechanisms of mat formation have been particularly well characterized in Pseudomonas fluorescens SBW25; mutations that lead to an increase in c-di-GMP production by diguanylate cyclases (WspR, AwsR, or MwsR) result in the secretion of cellulose, and mat formation. Here, we characterize and compare mat formation in two close relatives of SBW25: Pseudomonas simiae PICF7 and Pseudomonas fluorescens A506. We find that PICF7 – the strain more closely related to SBW25 – can form mats through mutations affecting the activity of the same three diguanylate cyclases as SBW25. However, instead of cellulose, these mutations activate the production of the Pel exopolysaccharide. We also provide evidence for at least two further – as yet uncharacterized – routes to PICF7 mat formation. P. fluorescens A506, while retaining the same mutational routes to mat formation as SBW25 and PICF7, forms mats by a semi-heritable mechanism that likely culminates in Pga and/or Psl production. Overall, our results demonstrate a high level of evolutionary flexibility in the molecular and structural routes to mat formation, even among close relatives.

scholarly journals The Inhibitory Site of a Diguanylate Cyclase Is a Necessary Element for Interaction and Signaling with an Effector Protein

2016 ◽  
Vol 198 (11) ◽  
pp. 1595-1603 ◽  
Author(s):  
Kurt M. Dahlstrom ◽  
Krista M. Giglio ◽  
Holger Sondermann ◽  
George A. O'Toole
Keyword(s):  
Pseudomonas Fluorescens ◽  
Small Molecule ◽  
Regulatory Element ◽  
Physical Interaction ◽  
Diguanylate Cyclase ◽  
Content Type ◽  
Target Proteins ◽  
Signaling Specificity ◽  
Diguanylate Cyclases ◽  
Gmp Production

ABSTRACTMany bacteria contain large cyclic diguanylate (c-di-GMP) signaling networks made of diguanylate cyclases (DGCs) and phosphodiesterases that can direct cellular activities sensitive to c-di-GMP levels. While DGCs synthesize c-di-GMP, many DGCs also contain an autoinhibitory site (I-site) that binds c-di-GMP to halt excess production of this small molecule, thus controlling the amount of c-di-GMP available to bind to target proteins in the cell. Many DGCs studied to date have also been found to signal for a specific c-di-GMP-related process, and although recent studies have suggested that physical interaction between DGCs and target proteins may provide this signaling fidelity, the importance of the I-site has not yet been incorporated into this model. Our results fromPseudomonas fluorescensindicate that mutation of residues at the I-site of a DGC disrupts the interaction with its target receptor. By creating various substitutions to a DGC's I-site, we show that signaling between a DGC (GcbC) and its target protein (LapD) is a combined function of the I-site-dependent protein-protein interaction and the level of c-di-GMP production. The dual role of the I-site in modulating DGC activity as well as participating in protein-protein interactions suggests caution in interpreting the function of the I-site as only a means to negatively regulate a cyclase. These results implicate the I-site as an important positive and negative regulatory element of DGCs that may contribute to signaling specificity.IMPORTANCESome bacteria contain several dozen diguanylate cyclases (DGCs), nearly all of which signal to specific receptors using the same small molecule, c-di-GMP. Signaling specificity in these networks may be partially driven by physical interactions between DGCs and their receptors, in addition to the autoinhibitory site of DGCs preventing the overproduction of c-di-GMP. In this study, we show that disruption of the autoinhibitory site of a DGC inPseudomonas fluorescenscan result in the loss of interactions with its target receptor and reduced biofilm formation, despite increased production of c-di-GMP. Our findings implicate the autoinhibitory site as both an important feature for signaling specificity through the regulation of c-di-GMP production and a necessary element for the physical interaction between a diguanylate cyclase and its receptor.

Rapid, efficient and dose-controlled delivery of liquid aerosol to pulmonary cells cultured at the air-liquid interface

Pneumologie ◽  
2011 ◽  
Vol 65 (12) ◽  
Author(s):  
M Selmansberger ◽  
AG Lenz ◽  
M Schmidmeir ◽  
O Eickelberg ◽  
T Stoeger ◽  
...  
Keyword(s):  
Liquid Interface ◽  
Controlled Delivery ◽  
Pulmonary Cells ◽  
Air Liquid Interface ◽  
Cells Cultured

Zwischen Luft und Wasser – Air-Liquid-Interface-Kulturen als In-vitro-Modell des Respirationstrakts

2020 ◽  
Author(s):  
S. Runft ◽  
L. Burigk ◽  
A. Lehmbecker ◽  
K. Schöne ◽  
D. Waschke ◽  
...  
Keyword(s):  
Liquid Interface ◽  
Air Liquid Interface

scholarly journals Drag on a spherical particle at the air–liquid interface: Interplay between compressibility, Marangoni flow, and surface viscosities

2021 ◽  
Vol 33 (6) ◽  
pp. 062103
Author(s):  
Meisam Pourali ◽  
Martin Kröger ◽  
Jan Vermant ◽  
Patrick D. Anderson ◽  
Nick O. Jaensson
Keyword(s):  
Spherical Particle ◽  
Liquid Interface ◽  
Marangoni Flow ◽  
Air Liquid Interface

Nonclassical Surface Nucleation of 6CB at the Air–Liquid Interface of a 6CB Oil-in-Water Nanoemulsion

Langmuir ◽  
2021 ◽  
Author(s):  
Jin Tae Park ◽  
Govind Paneru ◽  
Masao Iwamatsu ◽  
Bruce M. Law ◽  
Hyuk Kyu Pak
Keyword(s):  
Liquid Interface ◽  
Surface Nucleation ◽  
Oil In Water ◽  
Air Liquid Interface

scholarly journals Effect of Alpha-1 Antitrypsin on CFTR Levels in Primary Human Airway Epithelial Cells Grown at the Air-Liquid-Interface

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2639
Author(s):  
Frauke Stanke ◽  
Sabina Janciauskiene ◽  
Stephanie Tamm ◽  
Sabine Wrenger ◽  
Ellen Luise Raddatz ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Human Lung ◽  
Liquid Interface ◽  
Lung Epithelial Cells ◽  
Western Blots ◽  
Mesenchymal Transition ◽  
Protein Levels ◽  
Lung Epithelial ◽  
Cftr Protein ◽  
Air Liquid Interface

The cystic fibrosis transmembrane conductance regulator (CFTR) gene is influenced by the fundamental cellular processes like epithelial differentiation/polarization, regeneration and epithelial–mesenchymal transition. Defects in CFTR protein levels and/or function lead to decreased airway surface liquid layer facilitating microbial colonization and inflammation. The SERPINA1 gene, encoding alpha1-antitrypsin (AAT) protein, is one of the genes implicated in CF, however it remains unknown whether AAT has any influence on CFTR levels. In this study we assessed CFTR protein levels in primary human lung epithelial cells grown at the air-liquid-interface (ALI) alone or pre-incubated with AAT by Western blots and immunohistochemistry. Histological analysis of ALI inserts revealed CFTR- and AAT-positive cells but no AAT-CFTR co-localization. When 0.5 mg/mL of AAT was added to apical or basolateral compartments of pro-inflammatory activated ALI cultures, CFTR levels increased relative to activated ALIs. This finding suggests that AAT is CFTR-modulating protein, albeit its effects may depend on the concentration and the route of administration. Human lung epithelial ALI cultures provide a useful tool for studies in detail how AAT or other pharmaceuticals affect the levels and activity of CFTR.

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