A5069227905- Bacterial biofilms and quorum sensing
- Antimicrobial Peptides and Activities
- Lipid Membrane Structure and Behavior
- Micro and Nano Robotics
- Immune Response and Inflammation
- Bacteriophages and microbial interactions
- Bacterial Genetics and Biotechnology
- Microfluidic and Bio-sensing Technologies
- Microbial Community Ecology and Physiology
- Protein Structure and Dynamics
- Circadian rhythm and melatonin
- Oral microbiology and periodontitis research
- Plant and Biological Electrophysiology Studies
- Mitochondrial Function and Pathology
- Slime Mold and Myxomycetes Research
- Cell Image Analysis Techniques
- Biochemical and Structural Characterization
- Molecular Communication and Nanonetworks
- Photoreceptor and optogenetics research
- Probiotics and Fermented Foods
- Coastal wetland ecosystem dynamics
- Legume Nitrogen Fixing Symbiosis
- Vibrio bacteria research studies
- Bacillus and Francisella bacterial research
- Polydiacetylene-based materials and applications
California NanoSystems Institute
2016-2024
University of California, Los Angeles
2016-2024
University of California, Berkeley
2024
La Jolla Bioengineering Institute
2020
University of Massachusetts Chan Medical School
1983
Massachusetts Institute of Technology
1983
The second messenger signaling molecule cyclic diguanylate monophosphate (c-di-GMP) drives the transition between planktonic and biofilm growth in many bacterial species. Pseudomonas aeruginosa has two surface sensing systems that produce c-di-GMP response to adherence. Current thinking field is once cells attach a surface, they uniformly respond by producing c-di-GMP. Here, we describe how Wsp system generates heterogeneity sensing, resulting physiologically distinct subpopulations of...
It is unclear how severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection leads to the strong but ineffective inflammatory response that characterizes Coronavirus disease 2019 (COVID-19), with amplified immune activation in diverse cell types, including cells without angiotensin-converting enzyme receptors necessary for infection. Proteolytic degradation of SARS-CoV-2 virions a milestone host viral clearance, impact remnant peptide fragments from high loads not known. Here, we...
Significance Bacteria use multigenerational memory based on coupled oscillations of cAMP levels and type IV pili (TFP) activity to adaptively adhere surfaces. These create cells with a “surface-sentient” state intermediate between planktonic sessile, characterized by coordinated surface motility suppression. This drastically increases the number nonmotile correlates transition in family tree architectures toward exponential population growth. Our data support idea that reversible attachment...
What are bacteria doing during "reversible attachment," the period of transient surface attachment when they initially engage a surface, besides attaching themselves to surface? Can an cell help any other attach? If so, does it all cells or employ more selective strategy either nearby (spatial neighbors) its progeny (temporal neighbors)? Using community tracking methods at single-cell resolution, we suggest answers these questions based on how reversible progresses sensing for Pseudomonas...
Significance Here, we discover prototypical pacemaker neurons in the ancient cnidarian Hydra and provide evidence for a direct interaction of these with commensal microbiota. We uncover remarkable gene-expression program conservation between cells Caenorhabditis elegans mammalian gut. suggest that emerged as using components innate immunity to interact microbial environment ion channels generate rhythmic contractions. The communication microbiota represents mechanistic link gut motility. Our...
ABSTRACT Swarming is a macroscopic phenomenon in which surface bacteria organize into motile population. The flagellar motor that drives swarming Pseudomonas aeruginosa powered by stators MotAB and MotCD. Deletion of the MotCD stator eliminates swarming, whereas deletion enhances swarming. Interestingly, we measured strongly asymmetric availability wild-type (WT) strain, with produced at an approximately 40-fold higher level than stators. However, utilization free swimming cells requires...
The c2 repressor of bacteriophage P22 can be digested with trypsin, chymotrypsin, or elastase to yield stable fragments. Purified NH2-terminal fragments, like intact repressor, bind specifically operator DNA and also mediate positive negative control transcription. COOH-terminal fragments do not but undergo a concentration-dependent oligomerization similar that observed repressor. These results suggest the related cI phage lambda, contains two structural domains which different functions molecule.
Bacteria exhibit surface motility modes that play pivotal roles in early-stage biofilm community development, such as type IV pili-driven "twitching" and flagellum-driven "spinning" "swarming" motility. Appendage-driven is controlled by molecular motors, analysis of behavior complicated its inherently 3D nature, the speed which too fast for confocal microscopy to capture. Here, we combine electromagnetic field computation statistical image generate movies close a at 5 ms time resolution...
The bacterial amyloid curli, produced by Enterobacteriales including Salmonella species and Escherichia coli , is implicated in the pathogenesis of several complex autoimmune diseases. Curli binds to extracellular DNA, these complexes drive autoimmunity via production anti-double-stranded DNA autoantibodies. Here, we investigated immune activation phenol-soluble modulins (PSMs), proteins expressed Staphylococcus species. We confirmed nature PSMs S. aureus using a novel specific stain, ( E E)...
Deterministic formation of membrane scission necks by protein machinery with multiplexed functions is critical in biology. A microbial example M2 viroporin, a proton pump from the influenza virus that remodeling activity to induce budding and host during viral maturation. In comparison, dynamin family constitutes class eukaryotic proteins implicated mitochondrial fission, as well various endocytosis pathways. case Dnm1, fission yeast, mechanoenzyme create necks. It not clear why these are...
Monotrichous bacteria on surfaces exhibit complex spinning movements. Such motility is often a part of the surface detachment launch sequence these cells. To understand impact bacterial interactions, we develop hydrodynamic model surface-bound bacterium, which reproduces behaviours that observe in Pseudomonas aeruginosa , Shewanella oneidensis and Vibrio cholerae provides detailed dictionary for connecting observed behaviour to bacteria–surface interactions. Our findings indicate fraction...
Antimicrobial compounds first arose in prokaryotes by necessity for competitive self-defense. In this light, invented the host defense peptides. Among most well-characterized of these peptides are class II bacteriocins, ribosomally-synthesized polypeptides produced chiefly Gram-positive bacteria. current study, a tensor search protocol—the BACII algorithm—was created to identify and classify bacteriocin sequences with high fidelity. The algorithm integrates consensus signature sequence,...
Cell size control and homeostasis are fundamental features of bacterial metabolism. Recent work suggests that cells add a constant between birth division ("adder" model). However, it is not known how cell influenced by the existence heterogeneous microenvironments, such as those during biofilm formation. Shewanella oneidensis MR-1 can use diverse energy sources on range surfaces via extracellular electron transport (EET), which impact growth, metabolism, diversity. Here, we track surface...
Peptide-induced transmembrane pore formation is commonplace in biology. Examples of pores include formed by antimicrobial peptides (AMPs) and cell-penetrating (CPPs) bacterial membranes eukaryotic membranes, respectively. In general, however, depends on peptide sequences, lipid compositions, intensive thermodynamic variables difficult to observe directly under realistic solution conditions, with structures that are challenging measure directly. contrast, the structure phase behavior...
Deposition of human amyloids is associated with complex diseases such as Alzheimer’s and Parkinson’s. Amyloid proteins are also produced by bacteria. The bacterial amyloid curli, found in the extracellular matrix both commensal pathogenic enteric biofilms, forms complexes DNA, recognition these host immune system may initiate an autoimmune response. Here, we isolated early intermediate, mature curli fibrils that form throughout biofilm development investigated structural properties each....
Candida albicans is a commensal organism that causes life-threatening or life-altering opportunistic infections. Treatment of infections limited by the paucity antifungal drug classes. Naturally occurring antimicrobial peptides are promising agents for development. CCL28 CC chemokine abundant in saliva and has vitro activity. In this study, we examine vivo killing capacity oropharyngeal candidiasis as well spectrum mechanism anti-Candida mouse model candidiasis, application wild-type reduces...
The downregulation of Pseudomonas aeruginosa flagellar motility is a key event in biofilm formation, host colonization, and the formation microbial communities, but external factors that repress are not well understood. Here, we report on soft agar, swarming can be repressed by cells nonmotile due to absence flagellum or rotation. Mutants lack either biosynthesis rotation, when present at as little 5% total population, suppressed wild-type cells. Non-swarming required functional type IV pili...
Hopanoids are steroid-like bacterial lipids that enhance membrane rigidity and promote growth under diverse stresses. Hopanoid biosynthesis genes conserved in nitrogen-fixing plant symbionts, we previously found the extended (C 35 ) class of hopanoids Bradyrhizobium diazoefficiens required for efficient symbiotic nitrogen fixation tropical legume host Aeschynomene afraspera. Here, demonstrate nitrogen-fixation defect conferred by hopanoid loss can be fully explained a reduction root nodule...
Antimicrobial peptides (AMPs) are a class of molecules which generally kill pathogens via preferential cell membrane disruption. Chemokines family signaling proteins that direct immune migration and share conserved α–β tertiary structure. Recently, it was found subset chemokines can also function as AMPs, including CCL20, CXCL4, XCL1. It is therefore surprising machine learning based analysis predicts CCL20 CXCL4's α-helices disruptive, while XCL1's helix not. XCL1, however, the only...