scholarly journals Mechanistic insight into the conserved allosteric regulation of periplasmic proteolysis by the signaling molecule cyclic-di-GMP

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Debashree Chatterjee ◽  
Richard B Cooley ◽  
Chelsea D Boyd ◽  
Ryan A Mehl ◽  
George A O'Toole ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Bacterial Species ◽  
Adaptation Strategy ◽  
Bacterial Biofilm ◽  
Surface Adhesion ◽  
Receptor System ◽  
Changing Environments ◽  
Mechanistic Insight ◽  
A Cell ◽  
Insight Into

Stable surface adhesion of cells is one of the early pivotal steps in bacterial biofilm formation, a prevalent adaptation strategy in response to changing environments. In Pseudomonas fluorescens, this process is regulated by the Lap system and the second messenger cyclic-di-GMP. High cytoplasmic levels of cyclic-di-GMP activate the transmembrane receptor LapD that in turn recruits the periplasmic protease LapG, preventing it from cleaving a cell surface-bound adhesin, thereby promoting cell adhesion. In this study, we elucidate the molecular basis of LapG regulation by LapD and reveal a remarkably sensitive switching mechanism that is controlled by LapD's HAMP domain. LapD appears to act as a coincidence detector, whereby a weak interaction of LapG with LapD transmits a transient outside-in signal that is reinforced only when cyclic-di-GMP levels increase. Given the conservation of key elements of this receptor system in many bacterial species, the results are broadly relevant for cyclic-di-GMP- and HAMP domain-regulated transmembrane signaling.

Archaeal biofilms: widespread and complex

2013 ◽  
Vol 41 (1) ◽  
pp. 393-398 ◽  
Author(s):  
Sabrina Fröls
Keyword(s):  
Biofilm Formation ◽  
Extracellular Polymeric Substances ◽  
Bacterial Species ◽  
Surface Adhesion ◽  
Form Complex ◽  
Abiotic Surfaces ◽  
Archaeal Species ◽  
Physical And Chemical ◽  
Insight Into ◽  
Mixed Communities

Biofilms or multicellular structures become accepted as the dominant microbial lifestyle in Nature, but in the past they were only studied extensively in bacteria. Investigations on archaeal monospecies cultures have shown that many archaeal species are able to adhere on biotic and abiotic surfaces and form complex biofilm structures. Biofilm-forming archaea were identified in a broad range of extreme and moderate environments. Natural biofilms observed are mostly mixed communities composed of archaeal and bacterial species of various abundances. The physiological functions of the archaea identified in such mixed communities suggest a significant impact on the biochemical cycles maintaining the flow and recycling of the nutrients on earth. Therefore it is of high interest to investigate the characteristics and mechanisms underlying the archaeal biofilm formation. In the present review, I summarize and discuss the present investigations of biofilm-forming archaeal species, i.e. their diverse biofilm architectures in monospecies or mixed communities, the identified EPSs (extracellular polymeric substances), archaeal structures mediating surface adhesion or cell–cell connections, and the response to physical and chemical stressors implying that archaeal biofilm formation is an adaptive reaction to changing environmental conditions. A first insight into the molecular differentiation of cells within archaeal biofilms is given.

scholarly journals Lessons in Fundamental Mechanisms and Diverse Adaptations from the 2015 Bacterial Locomotion and Signal Transduction Meeting

2015 ◽  
Vol 197 (19) ◽  
pp. 3028-3040 ◽  
Author(s):  
Birgit M. Prüβ ◽  
Jun Liu ◽  
Penelope I. Higgs ◽  
Lynmarie K. Thompson
Keyword(s):  
Signal Transduction ◽  
Biofilm Formation ◽  
Cell Biology ◽  
Bacterial Species ◽  
Interacting Proteins ◽  
Mathematical Methods ◽  
Detailed Understanding ◽  
Rapid Changes ◽  
Functional Mechanisms ◽  
Insight Into

In response to rapid changes in their environment, bacteria control a number of processes, including motility, cell division, biofilm formation, and virulence. Research presented in January 2015 at the biennial Bacterial Locomotion and Signal Transduction (BLAST) meeting in Tucson, AZ, illustrates the elegant complexity of the nanoarrays, nanomachines, and networks of interacting proteins that mediate such processes. Studies employing an array of biophysical, genetic, cell biology, and mathematical methods are providing an increasingly detailed understanding of the mechanisms of these systems within well-studied bacteria. Furthermore, comparisons of these processes in diverse bacterial species are providing insight into novel regulatory and functional mechanisms. This review summarizes research presented at the BLAST meeting on these fundamental mechanisms and diverse adaptations, including findings of importance for applications involving bacteria of medical or agricultural relevance.

scholarly journals Ribosome dimerization prevents loss of essential ribosomal proteins during quiescence

2019 ◽  
Author(s):  
Heather A. Feaga ◽  
Mykhailo Kopylov ◽  
Jenny Kim Kim ◽  
Marko Jovanovic ◽  
Jonathan Dworkin
Keyword(s):  
Ribosomal Proteins ◽  
Bacterial Species ◽  
Small Subunit ◽  
Positive Bacterium ◽  
Dimer Interface ◽  
Mechanistic Insight ◽  
Energy Consuming ◽  
Higher Eukaryotes ◽  
Favorable Conditions ◽  
Insight Into

AbstractThe formation of ribosome dimers during periods of quiescence is widespread among bacteria and some higher eukaryotes. However, the mechanistic importance of dimerization is not well understood. In bacteria ribosome dimerization is mediated by the Hibernation Promoting Factor (HPF). Here, we report that HPF from the Gram-positive bacterium Bacillus subtilis preserves active ribosomes by preventing the loss of essential ribosomal proteins. Ribosomes isolated from strains either lacking HPF (Δhpf) or encoding a mutant allele of HPF that binds the ribosome but does not mediate dimerization were substantially depleted of the small subunit proteins S2 and S3. Strikingly, these proteins are located at the ribosome dimer interface. We used single particle cryo-EM to further characterize ribosomes isolated from a Δhpf mutant strain and observed that many were missing S2, S3, or both. These data support a model in which the ribosome dimerization activity of HPF evolved to protect labile proteins that are essential for ribosome function.Significance StatementWhen nutrients become scarce, many bacterial species enter an extended state of quiescence. A major challenge of this state is how to attenuate protein synthesis, the most energy consuming cellular process, while preserving ribosomes for the return to favorable conditions. Here, we show that the ribosome-binding protein HPF which dimerizes ribosomes functions to protect essential ribosomal proteins at the dimer interface. HPF is almost universally conserved in bacteria and HPF deletions in diverse species exhibit decreased viability under nutrient limitation. Our data provide mechanistic insight into this phenotype and establish a role for HPF in maintaining translationally competent ribosomes during quiescence.

scholarly journals Structural Features Mediating Zinc Binding and Transfer in the AztABCD Zinc Transporter System

Biomolecules ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1156 ◽  
Author(s):  
Anusha Meni ◽  
Erik T. Yukl
Keyword(s):  
Abc Transporters ◽  
Paracoccus Denitrificans ◽  
Bacterial Species ◽  
Structural Features ◽  
Zinc Binding ◽  
Transfer Model ◽  
Zinc Transport ◽  
Dissociation Kinetics ◽  
Mechanistic Insight ◽  
Insight Into

Many bacteria require ATP binding cassette (ABC) transporters for the import of the essential metal zinc from limited environments. These systems rely on a periplasmic or cell-surface solute binding protein (SBP) to bind zinc with high affinity and specificity. AztABCD is one such zinc transport system recently identified in a large group of diverse bacterial species. In addition to a classical SBP (AztC), the operon also includes a periplasmic metallochaperone (AztD) shown to transfer zinc directly to AztC. Crystal structures of both proteins from Paracoccus denitrificans have been solved and suggest several structural features on each that may be important for zinc binding and transfer. Here we determine zinc binding affinity, dissociation kinetics, and transfer kinetics for several deletion mutants as well as a crystal structure for one of them. The results indicate specific roles for loop structures on AztC and an N-terminal motif on AztD in zinc binding and transfer. These data are consistent with a structural transfer model proposed previously and provide further mechanistic insight into the processes of zinc binding and transfer.

scholarly journals Inhibition of Salmonella enterica Biofilm Formation Using Small-Molecule Adenosine Mimetics

2014 ◽  
Vol 59 (1) ◽  
pp. 76-84 ◽  
Author(s):  
Jacob A. Koopman ◽  
Joanna M. Marshall ◽  
Aditi Bhatiya ◽  
Tadesse Eguale ◽  
Jesse J. Kwiek ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Biofilm Formation ◽  
Mammalian Cells ◽  
Bacterial Species ◽  
Binding Pocket ◽  
Bacterial Biofilm ◽  
Chronic Infections ◽  
Content Type ◽  
Cellular Processes ◽  
Serovar Typhimurium

ABSTRACTBiofilms have been widely implicated in chronic infections and environmental persistence ofSalmonella enterica, facilitating enhanced colonization of surfaces and increasing the ability of the bacteria to be transmitted to new hosts.Salmonella entericaserovar Typhi biofilm formation on gallstones from humans and mice enhances gallbladder colonization and bacterial shedding, whileSalmonella entericaserovar Typhimurium biofilms facilitate long-term persistence in a number of environments important to food, medical, and farming industries.Salmonellaregulates expression of many virulence- and biofilm-related processes using kinase-driven pathways. Kinases play pivotal roles in phosphorylation and energy transfer in cellular processes and possess an ATP-binding pocket required for their functions. Many other cellular proteins also require ATP for their activity. Here we test the hypothesis that pharmacological interference with ATP-requiring enzymes utilizing adenosine mimetic compounds would decrease or inhibit bacterial biofilm formation. Through the screening of a 3,000-member ATP mimetic library, we identified a single compound (compound 7955004) capable of significantly reducing biofilm formation byS. Typhimurium andS. Typhi. The compound was not bactericidal or bacteriostatic towardS. Typhimurium or cytotoxic to mammalian cells. An ATP-Sepharose affinity matrix technique was used to discover potential protein-binding targets of the compound and identified GroEL and DeoD. Compound 7955004 was screened against other known biofilm-forming bacterial species and was found to potently inhibit biofilms ofAcinetobacter baumanniias well. The identification of a lead compound with biofilm-inhibiting capabilities towardSalmonellaprovides a potential new avenue of therapeutic intervention againstSalmonellabiofilm formation, with applicability to biofilms of other bacterial pathogens.

scholarly journals Structural insight into protein-aided bacterial biofilm formation

2017 ◽  
Vol 73 (a2) ◽  
pp. C391-C391
Author(s):  
Yvette Roske ◽  
Anne Diehl ◽  
Udo Heinemann ◽  
Hartmut Oschkinat ◽  
Kürsad Turgay
Keyword(s):  
Biofilm Formation ◽  
Bacterial Biofilm ◽  
Structural Insight ◽  
Insight Into

scholarly journals Structural insight into protein-aided bacterial biofilm formation

2018 ◽  
Vol 74 (a2) ◽  
pp. e206-e206
Author(s):  
Yvette Roske ◽  
Anne Diehl ◽  
Linda Ball ◽  
Kürsad Turgay ◽  
Udo Heinemann ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Bacterial Biofilm ◽  
Structural Insight ◽  
Insight Into

scholarly journals The glucuronyltransferase B4GAT1 is required for initiation of LARGE-mediated α-dystroglycan functional glycosylation

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Tobias Willer ◽  
Kei-ichiro Inamori ◽  
David Venzke ◽  
Corinne Harvey ◽  
Greg Morgensen ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Extracellular Matrix ◽  
Magnetic Resonance ◽  
Basement Membrane ◽  
Neuromuscular Disease ◽  
Glucuronic Acid ◽  
Magnetic Resonance Studies ◽  
Mechanistic Insight ◽  
A Cell ◽  
Insight Into

Dystroglycan is a cell membrane receptor that organizes the basement membrane by binding ligands in the extracellular matrix. Proper glycosylation of the α-dystroglycan (α-DG) subunit is essential for these activities, and lack thereof results in neuromuscular disease. Currently, neither the glycan synthesis pathway nor the roles of many known or putative glycosyltransferases that are essential for this process are well understood. Here we show that FKRP, FKTN, TMEM5 and B4GAT1 (formerly known as B3GNT1) localize to the Golgi and contribute to the O-mannosyl post-phosphorylation modification of α-DG. Moreover, we assigned B4GAT1 a function as a xylose β1,4-glucuronyltransferase. Nuclear magnetic resonance studies confirmed that a glucuronic acid β1,4-xylose disaccharide synthesized by B4GAT1 acts as an acceptor primer that can be elongated by LARGE with the ligand-binding heteropolysaccharide. Our findings greatly broaden the understanding of α-DG glycosylation and provide mechanistic insight into why mutations in B4GAT1 disrupt dystroglycan function and cause disease.

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.

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