A5036984709- Bacterial Genetics and Biotechnology
- Bacterial biofilms and quorum sensing
- Bacteriophages and microbial interactions
- Cell Image Analysis Techniques
- Escherichia coli research studies
- Dermatology and Skin Diseases
- Vibrio bacteria research studies
- Gut microbiota and health
- Image Processing Techniques and Applications
- Antibiotic Resistance in Bacteria
- Enzyme Structure and Function
- RNA and protein synthesis mechanisms
- Helicobacter pylori-related gastroenterology studies
- Advanced Fluorescence Microscopy Techniques
- Antimicrobial Peptides and Activities
- Diffusion and Search Dynamics
- Galectins and Cancer Biology
- Glycosylation and Glycoproteins Research
- Protein Structure and Dynamics
- Evolution and Genetic Dynamics
- Biochemical and Structural Characterization
- Genomics and Phylogenetic Studies
- Lipid Membrane Structure and Behavior
- Allergic Rhinitis and Sensitization
- CRISPR and Genetic Engineering
Princeton University
2016-2025
Institute for Integrative and Experimental Genomics
2018-2025
Bipar
2025
Vanderbilt University
2022-2024
Vanderbilt University Medical Center
2022-2024
Biology of Infection
2022-2023
University of Pennsylvania
2023
Vanderbilt Health
2022
University of Wisconsin–Madison
2009-2016
Madison Group (United States)
2009
Significance The bacterial actin homolog, MreB, is a key determinant of rod-cell shape but the mechanism by which it functions has remained topic much debate. Recently was shown that MreB exists as small polymers actively rotate around cell circumference. This rotation widely conserved, yet its and function have unknown. Here we show rotates because cytoplasmic filaments are coupled to periplasmic wall synthesis through transmembrane protein RodZ, acts linker. Furthermore, genetically...
The predatory deltaproteobacterium Myxococcus xanthus uses a helically-trafficked motor at bacterial focal-adhesion (bFA) sites to power gliding motility. Using total internal reflection fluorescence and force microscopies, we identify the von Willebrand A domain-containing outer-membrane (OM) lipoprotein CglB as an essential substratum-coupling adhesin of transducer (Glt) machinery bFAs. Biochemical genetic analyses reveal that localizes cell surface independently Glt apparatus; once there,...
The skin microbiome provides vital contributions to human health. However, the spatial organization and viability of its bacterial components remain unclear. Here, we apply culturing, imaging, molecular approaches mouse samples, find that surface is colonized by fewer viable bacteria than predicted DNA levels. Instead, skin-associated are predominantly located in hair follicles other cutaneous invaginations. Furthermore, show has a uniquely low fraction compared sites, indicating most on not...
Abstract Protein turnover is critical for proteostasis, but quantification challenging, and even in well-studied E. coli , proteome-wide measurements remain scarce. Here, we quantify the rates of ~3200 proteins under 13 conditions by combining heavy isotope labeling with complement reporter ion find that cytoplasmic are recycled when nitrogen limited. We use knockout experiments to assign substrates known ATP-dependent proteases. Surprisingly, none these proteases responsible observed...
The crowded bacterial cytoplasm is composed of biomolecules that span several orders magnitude in size and electrical charge. This complexity has been proposed as the source rich spatial organization apparent anomalous diffusion intracellular components, although this not tested directly. Here, we use biplane microscopy to track 3D motion self-assembled genetically encoded multimeric nanoparticles (bGEMs) with tunable (20 50 nm) charge (−3,240 +2,700 e) live Escherichia coli cells. To probe...
Facile diffusion of globular proteins within a cytoplasm that is dense with biopolymers essential to normal cellular biochemical activity and growth. Remarkably, Escherichia coli grows in minimal medium over wide range external osmolalities (0.03 1.8 osmol). The mean cytoplasmic biopolymer volume fraction ((phi)) for such adapted cells ranges from 0.16 at 0.10 osmol 0.36 1.45 osmol. For grown 0.28 osmol, similar phi obtained by plasmolysis (sudden osmotic upshift) using NaCl or sucrose as...
Abstract The actin-like protein MreB has been proposed to coordinate the synthesis of cell wall determine shape in bacteria. is preferentially localized areas with specific curved geometries, avoiding poles. It remains unclear whether MreB’s curvature preference regulated by additional factors, and which features promote rod growth. Here, we show that transmembrane RodZ modulates polymer number E. coli , properties are independently. An unbiased machine learning analysis shows number, total...
Helical cell shape is necessary for efficient stomach colonization by Helicobacter pylori, but the molecular mechanisms generating helical remain unclear. The centerline pitch and radius of wild-type H. pylori cells dictate surface curvatures considerably higher positive negative Gaussian than those present in straight- or curved-rod pylori. Quantitative 3D microscopy analysis short pulses with either N-acetylmuramic acid D-alanine metabolic probes showed that wall growth enhanced at both...
The spatial organization of DNA within the bacterial nucleoid remains unclear. To investigate chromosome in Escherichia coli, we examined relative positions ribosomal RNA (rRNA) operons space. seven rRNA are nearly identical and separated from each other by as much 180° on circular genetic map, a distance ≥2 million base pairs. By inserting binding sites for fluorescent proteins adjacent to then examining their pairwise live cells epifluorescence microscopy, found that all but rrnC close...
Studies of time-dependent drug and environmental effects on single, live bacterial cells would benefit significantly from a permeable, nonperturbative, long-lived fluorescent stain specific to the nucleoids (chromosomal DNA). The ideal not affect cell growth rate or nucleoid morphology dynamics, even during laser illumination for hundreds camera frames. In this study, time-dependent, single-cell fluorescence imaging with excitation sensitive electron-multiplying charge-coupled-device (EMCCD)...
By labeling the β' subunit of RNA polymerase (RNAP), we used fluorescence microscopy to study spatial distribution and diffusive motion RNAP in live Escherichia coli cells for first time. With a 40-ms time resolution, exhibits two or three narrow peaks 300- 600-nm full width at half-maximum that maintain their positions within 60 nm over 1 s. The intensity these features is 20 30% total. Fluorescence recovery after photobleaching (FRAP) measures on 1-μm length scale. Averaged many cells,...
The helical shape of Helicobacter pylori cells promotes robust stomach colonization; however, how the H. is determined unresolved. Previous work identified helical-cell-shape-promoting protein complexes containing a peptidoglycan-hydrolase (Csd1), peptidoglycan precursor synthesis enzyme (MurF), non-enzymatic homolog Csd1 (Csd2), transmembrane proteins (Csd5 and Csd7), bactofilin (CcmA). Bactofilins are highly conserved, spontaneously polymerizing cytoskeletal bacterial proteins. We sought...
A bstract Integrins are crucial for eukaryotic cell attachment and motility within the extracellular matrix (ECM) via focal-adhesion formation, with their evolutionary emergence important development of multicellularity. Intriguingly, single gliding cells predatory deltaproteobacterium Myxococcus xanthus form bacterial (bFA) sites; therein, helically-trafficked motors become immobilized at anchored locations through Glt apparatus association cell-surface integrin αI-domain-like adhesin CglB....
ABSTRACT The crowded bacterial cytoplasm is comprised of biomolecules that span several orders magnitude in size and electrical charge. This complexity has been proposed as the source rich spatial organization apparent anomalous diffusion intracellular components, although this not tested directly. Here, we use biplane microscopy to track 3D motion self-assembled Genetically Encoded Multimeric nanoparticles (bGEMs) with tunable (20 50 nm) charge (−2160 +1800 e) live Escherichia coli cells....
Photoperiodic time measurement is the ability of plants and animals to measure differences in day versus night length (photoperiod) use that information anticipate critical seasonal transformations, such as annual temperature cycles. This timekeeping phenomenon triggers adaptive responses higher organisms, gonadal stimulation, flowering, hibernation. Unexpectedly, we observed this capability cyanobacteria—unicellular prokaryotes with generation times short 5 6 hours. Cyanobacteria exposed...
Three-dimensional optical microscopy is often complicated by a refractive index mismatch between the sample and objective lens. This causes focal shift, difference motion focal-plane motion, that hinders accuracy of 3D reconstructions. We present two methods for measuring shift using fluorescent beads different sizes ring-stained beads. These simple are applicable to most situations, including total internal reflection objectives samples very close interface. For distances 0-1.5 μm into an...