Regulation of the synthesis of surface protein in the cell cycle of e. coli b/r

ABSTRACT The gene for the Salmonella enterica serovar Enteritidis fimbrial protein SefA was cloned into an Escherichia coli surface expression vector and confirmed by Western blot assay. E. coli clones expressing SefA attached to avian ovary granulosa cells and HEp-2 cells, providing evidence for the involvement of SefA in the ability of Salmonella to attach to eukaryotic cells.

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Molecular Characterization of Mycoplasma arthritidis Variable Surface Protein MAA2

Infection and Immunity ◽

10.1128/iai.66.6.2576-2586.1998 ◽

1998 ◽

Vol 66 (6) ◽

pp. 2576-2586 ◽

Cited By ~ 25

Author(s):

Leigh Rice Washburn ◽

Keith E. Weaver ◽

Elizabeth J. Weaver ◽

Wendy Donelan ◽

Suhaila Al-Sheboul

Keyword(s):

Amino Acid ◽

Signal Peptide ◽

Dna Sequences ◽

Surface Protein ◽

Carboxypeptidase Y ◽

Coding Region ◽

Intact Cells ◽

Mycoplasma Arthritidis ◽

E Coli ◽

Variable Surface

Earlier studies implied a role for Mycoplasma arthritidis surface protein MAA2 in cytadherence and virulence and showed that it exhibited both size and phase variability. Here we report the further analysis of MAA2 and the cloning and sequencing of the maa2 gene from two M. arthritidis strains, 158p10p9 and H606, expressing two size variants of MAA2. Triton X-114 partitioning and metabolic labeling with [3H]palmitic acid suggested lipid modification of MAA2. Surface exposure of the C terminus was indicated by cleavage of monoclonal antibody-specific epitopes from intact cells by carboxypeptidase Y. The maa2genes from both strains were highly conserved, consisting largely of six (for 158p10p9) or five (for H606) nearly identical, 264-bp tandem direct repeats. The deduced amino acid sequence predicted a largely hydrophilic, highly basic protein with a 29-amino-acid lipoprotein signal peptide. The maa2 gene was expressed inEscherichia coli from the lacZ promoter of vector pGEM-T. The recombinant product was approximately 3 kDa larger than the native protein, suggesting that the signal peptide was not processed in E. coli. The maa2 gene and upstream DNA sequences were cloned from M. arthritidisclonal variants differing in MAA2 expression state. Expression state correlated with the length of a poly(T) tract just upstream of a putative −10 box. Full-sized recombinant MAA2 was expressed inE. coli from genes derived from both ON and OFF expression variants, indicating that control of expression did not include alterations within the coding region.

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YakA, a protein kinase required for the transition from growth to development in Dictyostelium

Development ◽

10.1242/dev.125.12.2291 ◽

1998 ◽

Vol 125 (12) ◽

pp. 2291-2302 ◽

Cited By ~ 7

Author(s):

G.M. Souza ◽

S. Lu ◽

A. Kuspa

Keyword(s):

Cell Cycle ◽

Protein Kinase ◽

Basic Protein ◽

Mrna Levels ◽

Wild Type ◽

E Coli ◽

Cycle Arrest ◽

Expression Of Genes ◽

Extracellular Signal ◽

Nutrient Rich Medium

When Dictyostelium cells starve they arrest their growth and induce the expression of genes necessary for development. We have identified and characterized a protein kinase, YakA, that is essential for the proper regulation of both events. Amino acid sequence and functional similarities indicate that YakA is a homolog of Yak1p, a growth-regulating protein kinase in S. cerevisiae. Purified YakA expressed in E. coli is able to phosphorylate myelin basic protein. YakA-null cells are smaller and their cell cycle is accelerated relative to wild-type cells. When starved, YakA-null cells fail to decrease the expression of the growth-stage gene cprD, and do not induce the expression of genes required for the earliest stages of development. YakA mRNA levels increase during exponential growth and reach a maximum at the point of starvation, consistent with a role in mediating starvation responses. YakA mRNA also accumulates when cells are grown in medium conditioned by cells grown to high density, suggesting that yakA expression is under the control of an extracellular signal that accumulates during growth. Expression of yakA from a conditional promoter causes cell-cycle arrest in nutrient-rich medium and promotes developmental events, such as the expression of genes required for cAMP signaling. YakA appears to regulate the transition from growth to development in Dictyostelium.

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Antibiotic Resistance and Virulence Traits in Vancomycin-Resistant Enterococci (VRE) and Extended-Spectrum β-Lactamase/AmpC-producing (ESBL/AmpC) Enterobacteriaceae from Humans and Pets

Antibiotics ◽

10.3390/antibiotics9040152 ◽

2020 ◽

Vol 9 (4) ◽

pp. 152 ◽

Cited By ~ 4

Author(s):

Ramona Iseppi ◽

Alessandro Di Cerbo ◽

Patrizia Messi ◽

Carla Sabia

Keyword(s):

Antibiotic Resistance ◽

Virulence Factors ◽

Pcr Amplification ◽

Surface Protein ◽

Fecal Samples ◽

E Coli ◽

Microdilution Method ◽

Broth Microdilution Method ◽

Resistance Patterns ◽

Amoxicillin Clavulanate

Background: We investigated the virulence factors, genes, antibiotic resistance patterns, and genotypes (VRE and ESBL/AmpC) production in Enterococci and Enterobacteriaceae strains isolated from fecal samples of humans, dogs, and cats. Methods: A total of 100 fecal samples from 50 humans, 25 dogs, and 25 cats were used in the study. MICs of nine antimicrobials were determined using the broth microdilution method. Polymerase chain reaction was used for the detection of genes responsible for antibiotic resistance (VRE and ESBL/AmpC) and virulence genes both in Enterococcus species, such as cytolysin (cylA, cylB, cylM), aggregation substance (agg), gelatinase (gelE), enterococcal surface protein (esp), cell wall adhesins (efaAfs and efaAfm), and in Enterobacteriaceae, such as cytolysin (hemolysin) and gelatinase production (afa, cdt, cnf1, hlyA, iutA, papC, sfa). Results: Enterococcus faecium was the most prevalent species in humans and cats, whereas Enterococcus faecalis was the species isolated in the remaining samples. A total of 200 Enterobacteriaceae strains were also detected, mainly from humans, and Escherichia coli was the most frequently isolated species in all types of samples. In the Enterococcus spp, the highest percentages of resistance for ampicillin, amoxicillin/clavulanate, erythromycin, tetracycline, ciprofloxacin, teicoplanin, and vancomycin were detected in cat isolates (41.6%, 52.8%, 38.9%, 23.6%, 62.5%, 20.8%, and 23.6% respectively), and in E. coli, a higher rate of resistance to cefotaxime and ceftazidime emerged in cat and dog samples, if compared with humans (75.4% and 66.0%, 80.0% and 71.4%, and 32.0% and 27.2%, respectively). Regarding the total number of enterococci, 5% and 3.4% of the strains were vancomycin and teicoplanin resistant, and the vancomycin resistance (van A) gene has been detected in all samples by PCR amplification. All the Enterobacteriaceae strains were confirmed as ESBL producers by PCR and sequencing, and the most frequent ESBL genes in E. coli strains from humans and pet samples were blaCTX-M-1 and blaCTX-M-15. Conclusions: Our results provide evidence that one or more virulence factors were present in both genera, underlining again the ability of pet strains to act as pathogens.

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An E. coli-produced single-chain variable fragment (scFv) targeting hepatitis B virus surface protein potently inhibited virion secretion

Antiviral Research ◽

10.1016/j.antiviral.2018.12.019 ◽

2019 ◽

Vol 162 ◽

pp. 118-129 ◽

Cited By ~ 2

Author(s):

Cheng Li ◽

Yang Wang ◽

Tiantian Liu ◽

Matthias Niklasch ◽

Ke Qiao ◽

...

Keyword(s):

Hepatitis B Virus ◽

Hepatitis B ◽

Surface Protein ◽

Single Chain Variable Fragment ◽

Single Chain ◽

Virus Surface ◽

E Coli ◽

B Virus

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Immunogenicity of a DNA vaccine expressing the Neospora caninum surface protein NcSRS2 in mice

Acta Veterinaria Hungarica ◽

10.1556/avet.57.2009.1.5 ◽

2009 ◽

Vol 57 (1) ◽

pp. 51-62 ◽

Cited By ~ 2

Author(s):

Zhanzhong Zhao ◽

Jun Ding ◽

Qun Liu ◽

Ming Wang ◽

Jinshu Yu ◽

...

Keyword(s):

Immune Response ◽

Dna Vaccine ◽

Neospora Caninum ◽

Serum Antibody ◽

Pcr Amplification ◽

Surface Protein ◽

Cell Mediated Immunity ◽

E Coli ◽

Mammalian Expression ◽

Antibody Titres

The immunogenicity of a DNA vaccine expressing the surface protein NcSRS2 of Neospora caninum was studied in BALB/c mice. The NcSRS2-encoding DNA was obtained by PCR amplification of the NcSRS2 ORF gene from the p43 plasmid encoding the N. caninum surface protein NcSRS2, ligated to the mammalian expression vector pcDNA3.1/Zeo(+) and propagated in E. coli DH5α to produce the N. caninum NcSRS2 DNA vaccine. BALB/c mice were immunised by two intramuscular injections of the DNA vaccine with or without complete Freund’s adjuvant (CFA). Serum antibody titres and nitric oxide (NO) concentrations, and splenocyte proliferation and cytokine expression were measured after immunisation. The DNA vaccine induced T-cell-mediated immunity as shown by significantly increased NO concentrations, cytokine gene (IL-2 and IFN-γ) expression, and NcSRS2 protein-stimulated lymphocyte proliferation in mice immunised with the DNA vaccine. The vaccine also induced weak humoral immunity. The immunogenicity of the DNA vaccine was slightly enhanced by CFA. The immune response was specific to NcSRS2. No immune response was observed in mice immunised with the pcDNA3.1/Zeo(+) vector alone.

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A study of SeqA subcellular localization in Escherichia coli using photo-activated localization microscopy

Faraday Discussions ◽

10.1039/c5fd00058k ◽

2015 ◽

Vol 184 ◽

pp. 425-450 ◽

Cited By ~ 5

Author(s):

Jacek T. Mika ◽

Aster Vanhecke ◽

Peter Dedecker ◽

Toon Swings ◽

Jeroen Vangindertael ◽

...

Keyword(s):

Escherichia Coli ◽

Cell Cycle ◽

Bacterial Genome ◽

Genetically Engineered ◽

Replication Initiation ◽

Cell Protein ◽

Experimental Conditions ◽

Localization Microscopy ◽

E Coli ◽

Copy Numbers

Escherichia coli (E. coli) cells replicate their genome once per cell cycle to pass on genetic information to the daughter cells. The SeqA protein binds the origin of replication, oriC, after DNA replication initiation and sequesters it from new initiations in order to prevent overinitiation. Conventional fluorescence microscopy studies of SeqA localization in bacterial cells have shown that the protein is localized to discrete foci. In this study we have used photo-activated localization microscopy (PALM) to determine the localization of SeqA molecules, tagged with fluorescent proteins, with a localization precision of 20–30 nm with the aim to visualize the SeqA subcellular structures in more detail than previously possible. SeqA–PAmCherry was imaged in wild type E. coli, expressed from plasmid or genetically engineered into the bacterial genome, replacing the native seqA gene. Unsynchronized cells as well as cells with a synchronized cell cycle were imaged at various time points, in order to investigate the evolution of SeqA localization during the cell cycle. We found that SeqA indeed localized into discrete foci but these were not the only subcellular localizations of the protein. A significant amount of SeqA–PAmCherry molecules was localized outside the foci and in a fraction of cells we saw patterns indicating localization at the membrane. Using quantitative PALM, we counted protein copy numbers per cell, protein copy numbers per focus, the numbers of foci per cell and the sizes of the SeqA clusters. The data showed broad cell-to-cell variation and we did not observe a correlation between SeqA–PAmCherry protein numbers and the cell cycle under the experimental conditions of this study. The numbers of SeqA–PAmCherry molecules per focus as well as the foci sizes also showed broad distributions indicating that the foci are likely not characterized by a fixed number of molecules. We also imaged an E. coli strain devoid of the dam methylase (Δdam) and observed that SeqA–PAmCherry no longer formed foci, and was dispersed throughout the cell and localized to the plasma membrane more readily. We discuss our results in the context of the limitations of the technique.

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