A5079721014- Escherichia coli research studies
- Bacterial Genetics and Biotechnology
- Viral gastroenteritis research and epidemiology
- ATP Synthase and ATPases Research
- Enzyme Structure and Function
- Antibiotic Resistance in Bacteria
- Biochemical and Molecular Research
- Clostridium difficile and Clostridium perfringens research
- Bacteriophages and microbial interactions
- Near-Field Optical Microscopy
- Force Microscopy Techniques and Applications
- Vibrio bacteria research studies
- RNA Interference and Gene Delivery
- Integrated Circuits and Semiconductor Failure Analysis
- RNA and protein synthesis mechanisms
- Salmonella and Campylobacter epidemiology
- Monoclonal and Polyclonal Antibodies Research
- Advanced Fluorescence Microscopy Techniques
- Antimicrobial Peptides and Activities
- Advanced Electron Microscopy Techniques and Applications
- Drug Transport and Resistance Mechanisms
- Cellular Automata and Applications
- Nuclear Structure and Function
- Microbial Community Ecology and Physiology
- Enterobacteriaceae and Cronobacter Research
Utah State University
2014-2024
Oklahoma State University
2010-2015
University of Kansas
2006-2014
Photocatalytic upgrading of crucial biomass-derived intermediate chemicals (i.e., furfural alcohol, 5-hydroxymethylfurfural (HMF)) to value-added products (aldehydes and acids) was carried out on ultrathin CdS nanosheets (thickness ∼1 nm) decorated with nickel (Ni/CdS). More importantly, simultaneous H2 production realized upon visible light irradiation under ambient conditions utilizing these biomass intermediates as proton sources. The remarkable difference in the rates transformation...
Hot, Toxic Eukaryote Unusually, the single-celled eukaryote red alga, Galdieria sulphuraria , can thrive in hot, acidic springs. This organism is endowed with extraordinary metabolic talents and consume a variety of strange carbohydrates, as well turn on photosynthesis when food runs out. Schönknecht et al. (p. 1207 ; see Perspective by Rocha ) discerned from phylogenetic analysis its genome that during evolution, G. appears to have commandeered at least 75 bacterial archaeal genes...
ABSTRACT Shigella flexneri contact with enterocytes induces a burst of protein secretion via its type III apparatus (TTSA) as an initial step in cellular invasion. We have previously reported that IpaD is positioned at the TTSA needle tip (M. Espina et al., Infect. Immuno. 74:4391-4400, 2006). From this position, senses small molecules environment to control presentation IpaB tip. This occurs without induction or IpaC recruitment S. surface. then transported surface when target cell lipids...
Shigellosis is an important disease in the developing world, where about 90 million people become infected with Shigella spp. each year. We previously demonstrated that type three secretion apparatus (T3SA) proteins IpaB and IpaD are protective antigens mouse lethal pulmonary model. In order to simplify vaccine formulation process development, we have evaluated a design incorporates both of these tested into single polypeptide chain. To determine if this fusion protein (DB fusion) retains...
Shigella flexneri uses its type III secretion apparatus (TTSA) to inject host-altering proteins into targeted eukaryotic cells. The TTSA is composed of a basal body and an exposed needle with invasion plasmid antigen D (IpaD) forming tip complex that controls secretion. bile salt deoxycholate (DOC) stimulates recruitment the translocator protein IpaB maturing complex. This process appears be triggered by direct interaction between DOC IpaD. Fluorescence spectroscopy NMR are used here confirm...
Abstract Type III secretion (TTS) is an essential virulence factor for Shigella flexneri , the causative agent of shigellosis. The TTS apparatus (TTSA) elegant nano‐machine that composed a basal body, external needle to deliver effectors into human cells, and tip complex controls activation. IpaD at nascent TTSA where it first step bile salt deoxycholate (DOC) binds induce recruitment translocator protein IpaB maturing complex. We recently used spectroscopic analyses show undergoes...
Abstract The Shigella flexneri Type III secretion system (T3SS) senses contact with human intestinal cells and injects effector proteins that promote pathogen entry as the first step in causing life threatening bacillary dysentery (shigellosis). apparatus (T3SA) consists of an anchoring basal body, exposed needle, a temporally assembled tip complex. Exposure to environmental small molecules recruits IpaB, hydrophobic translocator protein, maturing IpaB then host cell membrane, forming...
Bacterial β-class carbonic anhydrases (CAs) are zinc metalloenzymes catalysing reversible hydration of CO2. They maintain the intracellular balance CO2/bicarbonate required for biosynthetic reactions and represent a new group antimicrobial drug targets. Genome sequence analysis Pseudomonas aeruginosa PAO1, an opportunistic human pathogen causing life threatening infections, identified three genes, PAO102, PA2053 PA4676, encoding putative β-CAs that share 28-45 % amino acid identity belong to...
The type III secretion system (T3SS) is an essential virulence factor for Shigella flexneri , providing a conduit through which host-altering effectors are injected directly into host cell to promote uptake. apparatus (T3SA) composed of basal body, external needle, and regulatory tip complex. nascent needle polymer MxiH capped by pentamer invasion plasmid antigen D (IpaD). Exposure bile salts (e.g., deoxycholate) causes conformational change in IpaD promotes recruitment IpaB the tip. It has...
Shigella flexneri uses its type III secretion system (T3SS) to promote invasion of human intestinal epithelial cells as the first step in causing shigellosis, a life-threatening form dysentery. The apparatus (T3SA) consists basal body that spans bacterial envelope and an exposed needle injects effector proteins into target cells. nascent T3SA is topped with pentamer tip protein plasmid antigen D (IpaD). Bile salts trigger recruitment hydrophobic translocator protein, IpaB, complex where it...
Like many Gram-negative pathogens, Shigella rely on a complex type III secretion system (T3SS) to inject effector proteins into host cells, take over functions, and ultimately establish infection. Despite these critical roles, the energetics regulatory mechanisms controlling T3SS pathogen virulence remain largely unclear. In this study, we present series of high resolution crystal structures Spa47 use model an activated oligomer, finding that ATP hydrolysis may be supported by specific side...
Shigella rely entirely on the action of a single type three secretion system (T3SS) to support cellular invasion colonic epithelial cells and circumvent host immune responses. The ATPase Spa47 resides at base needle-like apparatus (T3SA), supporting protein through providing likely means for native virulence regulation by much needed target non-antibiotic therapeutics treat infections. Here, we show that MxiN is differential regulator its regulatory impact determined oligomeric state ATPase,...
Abstract Gram‐negative pathogens often use conserved type three secretion systems (T3SS) for virulence. The Shigella apparatus (T3SA) penetrates the host cell membrane and provides a unidirectional conduit injection of effectors into cells. protein Spa47 localizes to base is speculated be an ATPase that energy T3SA formation secretion. Here, we developed expression purification protocol, producing active providing first direct evidence bona fide ATPase. Additionally, size exclusion...
Shigella spp. are causative agents of bacillary dysentery, a human illness with high global morbidity levels, particularly among elderly and infant populations. infects via the fecal-oral route, its virulence is dependent upon type III secretion system (T3SS). Two components exposed needle tip complex T3SS, invasion plasmid antigen D (IpaD) IpaB, have been identified as broadly protective antigens in mouse lethal pneumonia model. A recombinant fusion protein (DB fusion) was created by...
Shigella flexneri causes bacillary dysentery, an important cause of mortality among children in the developing world. secretes effector proteins via its type III secretion system (T3SS) to promote bacterial uptake into human colonic epithelial cells. The T3SS basal body spans cell envelope anchoring a surface-exposed needle. A pentamer invasion plasmid antigen D lies at nascent needle tip and B (IpaB) is recruited complex on exposure bile salts. From here, IpaB forms translocon pore host...
Type three secretion systems (T3SS) are specialized nanomachines that support infection by injecting bacterial proteins directly into host cells. The Shigella T3SS has uniquely evolved to sense environmental levels of the bile salt deoxycholate (DOC) and upregulate virulence in response DOC. In this study, we describe a rare i + 5 hydrogen bonding secondary structure element (π-helix) within type system tip protein IpaD plays critical role DOC-enhanced virulence. Specifically, engineered...
Type three secretion systems (T3SS) are complex nano-machines that evolved to inject bacterial effector proteins directly into the cytoplasm of eukaryotic cells. Many high-priority human pathogens rely on one or more T3SSs cause disease and evade host immune responses, underscoring need better understand mechanisms through which function their role(s) in supporting pathogen virulence. We recently identified Shigella protein Spa47 as an oligomerization-activated T3SS ATPase fuels supports...
Many important human pathogens rely on one or more type three secretion systems (T3SSs) to inject bacterial effector proteins directly into the host cell cytoplasm. Secretion of protein through needlelike apparatus (T3SA) is essential for pathogen virulence and relies a highly conserved ATPase at base apparatus, making it an attractive target anti-infective therapeutics. Here, we leveraged ability purify active oligomeric Shigella T3SS provide kinetic analyses inhibitors Spa47. In agreement...
Nuclear pore complexes (NPCs) are macromolecular pores that span the nuclear envelope and undergo conformational changes in response to cisternal calcium levels. Depletion of leads appearance a mass within pore. The identity role this central remain unknown, although some studies suggest they vault complexes. Vault 13 MDa ribonucleoproteins found cytoplasm recently nuclei species, suggesting associate with NPCs cross envelope. Using Förster resonance energy transfer (FRET) measurements...
Tip-induced sample heating in near-field scanning optical microscopy (NSOM) is studied for fiber optic probes fabricated using the chemical etching technique. To characterize from etched NSOM probes, spectra of a thermochromic polymer are measured as function probe output power, was previously reported pulled probes. The results reveal that increases rapidly to ∼55–60°C powers reach ∼50nW. At higher powers, remains approximately constant up maximum power ∼450nW. profiles consistent with...