A5080757631- Bacterial Genetics and Biotechnology
- Escherichia coli research studies
- Vibrio bacteria research studies
- Bacteriophages and microbial interactions
- Viral gastroenteritis research and epidemiology
- Metalloenzymes and iron-sulfur proteins
- Fungal and yeast genetics research
- RNA and protein synthesis mechanisms
- Clostridium difficile and Clostridium perfringens research
- Antibiotic Resistance in Bacteria
- Legume Nitrogen Fixing Symbiosis
- Salmonella and Campylobacter epidemiology
- Metal complexes synthesis and properties
- Enzyme Structure and Function
- Protist diversity and phylogeny
- Wastewater Treatment and Nitrogen Removal
- Bacterial biofilms and quorum sensing
- Ion channel regulation and function
- Heat shock proteins research
- Immune Response and Inflammation
- Plant Molecular Biology Research
- Microbial Fuel Cells and Bioremediation
- Plant Disease Resistance and Genetics
- Immunotherapy and Immune Responses
- PI3K/AKT/mTOR signaling in cancer
University of Castilla-La Mancha
2017-2024
University of Bristol
2007-2017
John Innes Centre
2004-2007
University of Alicante
2001-2002
Universidad de Murcia
1996-1998
Summary Type III secretion systems (T3SSs) are key determinants of virulence in many Gram‐negative bacteria, including animal and plant pathogens. They inject ‘effector’ proteins through a ‘needle’ protruding from the bacterial surface directly into eukaryotic cells after assembly ‘translocator’ pore host plasma membrane. Secretion is tightly regulated process, which blocked until physical contact with cell takes place. Host sensing occurs distal needle ‘tip complex’ translocators secreted...
Type III secretion systems (T3SSs) are protein injection devices essential for the interaction of many Gram-negative bacteria with eukaryotic cells. While Shigella assembles its T3SS when environmental conditions appropriate invasion, is only activated after physical contact a host cell. First, translocators secreted to form pore in cell membrane, followed by effectors which manipulate Secretion activation tightly controlled conserved components: needle tip proteins IpaD and IpaB, itself...
We have used an in vitro model of intestinal M cells to examine the mechanisms by which Salmonella enterica translocates across these specialized cells, constitute a primary site infection mammalian host. S. can invade cultured deploying type III secretion system (TTSS) encoded within pathogenicity island 1 (SPI-1) translocate effector proteins into host cell cytoplasm that trigger cellular responses, including prominent cytoskeletal rearrangements. After enters cell, second TTSS SPI-2...
Type III secretion systems are found in many Gram-negative bacteria. They activated by contact with eukaryotic cells and inject virulence proteins inside them. Host cell detection requires a protein complex located at the tip of device's external injection needle. The Shigella (TC) is composed IpaD, hydrophilic protein, IpaB, hydrophobic which later forms part pore host membrane. Here we used labelling crosslinking methods to show that TCs from ΔipaB strain contain five IpaD subunits while...
The NifA protein from Azotobacter vinelandii belongs to a family of enhancer binding proteins (EBPs) that activate transcription by RNA polymerase containing the sigma factor sigma(54). These have conserved AAA+ domains catalyse ATP hydrolysis drive conformational changes necessary for open complex formation sigma(54)-RNA polymerase. activity is highly regulated in response redox and fixed nitrogen through interaction with antiactivator NifL. Binding NifL inhibits ATPase NifA, this...
Most studies on Salmonella enterica serovar Typhimurium infection focus strains ATCC SL1344 or NTCC 12023 (ATCC 14028). We have compared the abilities of these to induce membrane ruffles and invade epithelial cells. S . strain is less invasive induces smaller MDCK cells with SL1344. Since SPI-1 effector SopE present in absent from 12023, sopE mutants reduced invasiveness, we investigated whether due absence SopE. However, comparison + − strains, deletion expressing a plasmid revealed no...
Type III secretion systems (T3SSs) are widely distributed virulence determinants of Gram-negative bacteria. They translocate bacterial proteins into host cells to manipulate them during infection. The Shigella T3SS consists a cytoplasmic bulb, transmembrane region, and hollow needle protruding from the surface. distal tip mature, quiescent needles is composed IpaD, which topped by IpaB. Physical contact with initiates leads assembly pore, formed IpaB IpaC, in cell membrane, through other...
Most effective nematicides for the control of root-knot nematodes are banned, which demands a better understanding plant-nematode interaction. Understanding how gene expression in nematode-feeding sites relates to morphological features may assist characterization However, nematode-induced galls resulting from cell-proliferation and hypertrophy hinders such observation, would require tissue sectioning or clearing. We demonstrate that method based on green auto-fluorescence produced by...
Enteropathogenic Escherichia coli (EPEC) is an extracellular pathogen that utilizes a type III secretion system (TTSS) to modulate diverse host cell processes including cytoskeletal dynamics, tight junction permeability and macrophage phagocytosis. Some EPEC strains exhibit selective tropism for the specialized follicle-associated epithelium (FAE) overlying lymphoid follicles in gut, which major site of uptake inert particulates pathogens, but do not translocate from intestinal lumen...
The bacterium Myxococcus xanthus responds to blue light by producing carotenoids. It also starvation conditions developing fruiting bodies, where the cells differentiate into myxospores. Each response entails transcriptional activation of a separate set genes. However, single gene, carD, is required for both light- and starvation-inducible Gene carD has now been sequenced. Its predicted amino acid sequence includes four repeats DNA-binding domain present in mammalian high mobility group I(Y)...
The necessity to respond the level of fixed nitrogen and external oxygen concentrations provide sufficient energy for fixation imposes common regulatory principles amongst diazotrophs. NifL–NifA system in Azotobacter vinelandii integrates signals redox, fixed-nitrogen carbon status regulate nif transcription. Multidomain signalling interactions between NifL NifA are modulated by redox changes, ligand binding interaction with signal-transduction protein GlnK. Under adverse conditions (excess...
ABSTRACT The EspF protein is secreted by the type III secretion system of enteropathogenic and enterohemorrhagic Escherichia coli (EPEC EHEC, respectively). sequences differ between EHEC O157:H7, O26:H11, EPEC O127:H6 in terms number SH3-binding polyproline-rich repeats specific residues these regions, as well amino domain involved cellular localization. O127 important for inhibition phagocytosis also limits translocation through antigen-sampling cells (M cells). has been shown to have...
SUMMARY Root‐knot nematodes (RKNs, Meloidogyne spp.) are sedentary biotrophic pathogens that establish within the vascular cylinder of plant roots, forming a gall and inducing several feeding cells, giant cells (GCs), essential for completion their life cycle. GCs suffer gene expression changes, repeated mitosis endoreduplication events. Transcriptomics has revealed an extensive down‐regulation transcripts, molecular signature early‐developing galls is conserved in tomato Arabidopsis, may be...
Expression of the Myxococcus xanthus gene crtI is controlled by a light‐inducible promoter. The activity this promoter depends on CarQ, σ factor extracytoplasmic function (ECF) subfamily. Here, we show that minimum DNA stretch reproducing normal expression extends from few bases upstream −35 position to site well downstream transcriptional start. contains an enhancer‐like element remains active when displaced Experimental evidence provided for being critically dependent pentanucleotide...
Bacterial species can communicate by producing and sensing small autoinducer molecules a process known as quorum sensing. Salmonella enterica produces 2 (AI-2) via the luxS synthase gene, which is used some bacterial pathogens to coordinate virulence gene expression with population density. We investigated whether might affect ability of serovar Typhimurium invade epithelial cells. No differences were found between wild-type strain S. Typhimurium, SL1344, its isogenic mutant respect number...
We have investigated the impact of plasmids and GFP expression on invasion cultured epithelial cells by Salmonella enterica Typhimurium strain SL1344. The invasiveness SL1344 carrying derived from pBR322, encoding promoterless or constitutively expressed rpsM -GFP, was compared under optimal growth conditions with that SL1344(pBR322), unmodified a chromosome-integrated -GFP. pBR322 exhibited normal invasion, but presence modified impaired invasiveness, impairment exacerbated plasmid-encoded...
Signal transduction by two-component regulatory systems involves phosphorylation of the receiver domain a response regulator transmitter cognate histidine kinase. In NtrBC system, NtrC NtrB results in transcriptional activation nitrogen-regulated genes. We have used yeast two-hybrid system to probe interactions between domains and proteins from Klebsiella pneumoniae. constructed fusions each series or protein DNA-binding GAL4 analysed expression GAL1:lacZ GAL1:HIS3 reporters yeast. The...
Salicylidene acylhydrazides identified as inhibitors of virulence-mediating type III secretion systems (T3SSs) potentially target their inner membrane export apparatus. They also lead to inhibition flagellar T3SS-mediated swimming motility in Salmonella enterica serovar. Typhimurium. We show that INP0404 and INP0405 act by reducing the number flagella/cell. These molecules still inhibit a ΔfliH-fliI-fliJ/flhB(P28T) strain, which lacks three soluble components T3S apparatus, suggesting they...
ABSTRACT We have used the yeast two-hybrid system to analyze protein-protein interactions mediated by domains of regulatory proteins ntr signal transduction system, including among NtrB derivatives and their with NtrC PII from Klebsiella pneumoniae . Interactions took place only between or protein belonging not noncognate regulators. its transmitter domain, but NtrC, CheA, cytoplasmic C terminus EnvZ, interacted PII. In addition, interaction PII, depended on histidine phosphotransfer domain....
The type III secretion apparatus (T3SA), which is evolutionarily and structurally related to the bacterial flagellar hook basal body, a key virulence factor used by many Gram-negative bacteria inject effector proteins into host cells. A hollow extracellular needle forms injection conduit of T3SA. Its length tightly controlled match specific structures at host-cell surfaces but how this occurs remains incompletely understood. topped tip complex, senses cell inserts as translocation pore in...
The NifL protein from Azotobacter vinelandii senses both the redox and fixed nitrogen status to regulate fixation by controlling activity of transcriptional activator NifA. has a domain architecture similar that cytoplasmic histidine kinases. It contains two N-terminal PAS domains C-terminal transmitter region containing conserved residue (H domain) nucleotide binding GHKL corresponding catalytic core Despite these similarities, does not exhibit kinase regulates its partner NifA direct...