Recombinant Yersinia enterocolitica serotype O:8 / biotype 1B UPF0259 membrane protein YE2218 (YE2218)

What expression systems are recommended for recombinant YE2218 production?

For recombinant production of YE2218, E. coli-based expression systems have proven successful. The commercial recombinant protein utilizes an N-terminal His-tag fusion approach in E. coli, suggesting this is a viable expression strategy . For research purposes, the following protocol is recommended:

• Clone the full-length YE2218 gene (including nucleotides coding for amino acids 1-255) into an expression vector containing an N-terminal His-tag

• Transform into an E. coli strain optimized for membrane protein expression (e.g., C41(DE3) or C43(DE3))

• Induce expression at lower temperatures (16-20°C) to minimize inclusion body formation

• Use a Tris/PBS-based buffer system with 6% trehalose at pH 8.0 for protein extraction and storage

This approach has yielded recombinant YE2218 with greater than 90% purity as determined by SDS-PAGE .

What are the optimal storage and handling conditions for recombinant YE2218?

Recombinant YE2218 protein stability is maintained under the following conditions:

Following these handling protocols ensures maximum stability and activity of the recombinant protein .

How might YE2218 contribute to Y. enterocolitica pathogenicity?

While direct evidence for YE2218's role in pathogenicity is limited, several contextual factors suggest potential involvement:

• Y. enterocolitica serotype O:8 / biotype 1B is classified as highly pathogenic, suggesting membrane proteins like YE2218 may contribute to this virulence phenotype

• Membrane proteins in pathogenic bacteria often facilitate host-pathogen interactions, environmental sensing, or antimicrobial resistance

• The protein's conservation across pathogenic strains but not necessarily in non-pathogenic strains may indicate a virulence-associated function

Research into other membrane proteins in Y. enterocolitica has shown their importance in invasion, adherence, and resistance to host defense mechanisms . To definitively establish YE2218's role in pathogenicity, gene knockout studies followed by virulence assessment in mouse models would be necessary, similar to approaches used for other Yersinia virulence factors .

What is known about the regulation of YE2218 expression during infection?

• Many virulence-associated genes in Y. enterocolitica are temperature-regulated, with expression increasing at 37°C (host temperature) compared to environmental temperatures

• Type III secretion system regulators like YscM1 and YscM2 in Y. enterocolitica control expression of multiple virulence factors

• Environmental factors such as iron limitation, pH changes, and osmolarity can influence expression of membrane proteins in pathogenic bacteria

To investigate YE2218 regulation specifically, researchers should consider:

• qRT-PCR studies under various environmental conditions

• Reporter gene fusions to monitor expression in vivo

• Proteomic analysis comparing expression levels during various growth phases and infection states

How can YE2218 be used in vaccine development research against Y. enterocolitica?

Membrane proteins represent potential targets for vaccine development. For YE2218 specifically:

• Researchers could follow similar approaches to those used for other Yersinia membrane proteins, such as the bivalent fusion protein rVE (comprising regions of LcrV and YopE), which demonstrated effective protection against Y. enterocolitica challenge in mouse models

• YE2218 could be evaluated as a component in a multi-subunit vaccine by:

  • Assessing its immunogenicity in mouse models

  • Measuring antibody responses (both IgG1 and IgG2a/IgG2b isotypes)

  • Evaluating T-cell responses (CD4+ and CD8+ subsets)

  • Determining cytokine profiles (both Th1 and Th2)

The approach should evaluate both humoral and cell-mediated immune responses, as comprehensive protection against Yersinia requires both components .

What methodologies are most effective for studying potential interactions between YE2218 and host cell receptors?

To investigate interactions between YE2218 and host cell receptors, consider these methodologies:

• Pull-down assays

  • Use purified His-tagged YE2218 as bait with host cell lysates

  • Identify binding partners through mass spectrometry

• Surface Plasmon Resonance (SPR)

  • Immobilize YE2218 on sensor chips

  • Measure binding kinetics with potential host cell receptors

• Yeast Two-Hybrid Screening

  • Modified for membrane proteins using split-ubiquitin systems

  • Screen against human cDNA libraries from relevant tissues (intestinal epithelial cells)

• Infection Models with YE2218 Mutants

  • Generate YE2218 deletion mutants

  • Compare adherence and invasion capabilities with wild-type strains

  • Observe effects on pathogenicity in murine models similar to those used in other Yersinia virulence studies

These approaches would help elucidate YE2218's potential role in host-pathogen interactions.

What are common challenges in structural studies of YE2218 and how can they be addressed?

Membrane proteins like YE2218 present several challenges for structural studies:

When working with YE2218, researchers should particularly focus on detergent selection during solubilization and maintaining protein stability during concentration steps.

How can researchers distinguish between potential YE2218 isoforms or modified forms in experimental systems?

To distinguish between potential YE2218 isoforms or post-translationally modified forms:

• Western Blotting with Specific Antibodies

  • Develop antibodies against distinct regions of YE2218

  • Use phospho-specific antibodies if phosphorylation is suspected

• Mass Spectrometry-Based Approaches

  • Tryptic digestion followed by LC-MS/MS

  • Analysis of intact protein mass for different isoforms

  • Fragment analysis for identification of modification sites

• 2D Gel Electrophoresis

  • Separate proteins based on both pI and molecular weight

  • Identify shifts indicating post-translational modifications

• Pulse-Chase Experiments

  • Track protein processing and modification over time

  • Use radioactive labeling or click chemistry approaches

These techniques can help researchers characterize the different forms of YE2218 that may exist in native versus recombinant systems.

How might YE2218 relate to antimicrobial resistance mechanisms in Y. enterocolitica?

Recent research has identified multidrug resistance in clinical isolates of Y. enterocolitica . While YE2218's specific role in antimicrobial resistance has not been established, membrane proteins often contribute to resistance mechanisms through:

• Efflux pump functions

• Alteration of membrane permeability

• Modification of drug targets

• Cell wall/membrane remodeling

Investigation strategies could include:

• Comparing YE2218 sequence variations between susceptible and resistant strains

• Examining YE2218 expression levels in response to antibiotic exposure

• Creating YE2218 knockouts to assess changes in minimum inhibitory concentrations (MICs)

• Studying co-localization with known resistance determinants

The emergence of multidrug-resistant Y. enterocolitica strains makes this research direction particularly relevant.

What bioinformatic approaches should be used to identify potential functional domains within YE2218?

For comprehensive bioinformatic analysis of YE2218:

• Sequence-Based Analysis

  • Multiple sequence alignment with homologs across bacterial species

  • Identification of conserved domains using Pfam, SMART, or InterPro

  • Transmembrane topology prediction (TMHMM, Phobius)

  • Signal peptide prediction (SignalP)

• Structural Prediction

  • Secondary structure prediction (PSIPRED)

  • Tertiary structure modeling (AlphaFold2, RoseTTAFold)

  • Analysis of predicted binding pockets and functional sites

• Genomic Context Analysis

  • Examine operonic structure around YE2218

  • Identify potential co-regulated genes

  • Compare genomic organization across different Yersinia strains and isolates

• Integration with Experimental Data

  • Map experimental findings (mutagenesis, binding studies) onto predicted structures

  • Develop testable hypotheses about function based on integrated analysis

These approaches can help identify potential functional domains within YE2218 and guide experimental investigations.

How might CRISPR-Cas9 technologies be applied to study YE2218 function in Y. enterocolitica?

CRISPR-Cas9 technologies offer powerful approaches for investigating YE2218 function:

• Gene Knockout Studies

  • Create precise YE2218 deletions

  • Assess effects on growth, membrane integrity, and virulence

  • Study phenotypic changes under various stress conditions

• Gene Tagging Approaches

  • Insert fluorescent protein tags for localization studies

  • Add affinity tags for in vivo interaction studies

  • Create conditional expression systems

• Base Editing Applications

  • Introduce point mutations to study specific amino acid functions

  • Create libraries of YE2218 variants for functional screening

  • Modify potential regulatory regions to study expression control

• CRISPRi Approaches

  • Implement inducible knockdown of YE2218 expression

  • Study dosage effects on bacterial physiology and pathogenicity

  • Use as complementary approach to complete knockout studies

Each approach would need to be optimized for Y. enterocolitica, as CRISPR efficiency can vary between bacterial species.

What are the most promising comparative genomics approaches for understanding YE2218 evolution across Yersinia species?

To understand YE2218 evolution across Yersinia species, researchers should consider:

• Pan-genome Analysis

  • Compare presence/absence of YE2218 homologs across all sequenced Yersinia strains

  • Identify correlation between YE2218 presence and pathogenicity

• Positive Selection Analysis

  • Calculate dN/dS ratios to identify positions under positive selection

  • Map selected sites onto structural models to infer functional importance

• Genomic Island Analysis

  • Determine if YE2218 is located within mobile genetic elements

  • Compare to the high-pathogenicity island (HPI) structure identified in Y. enterocolitica

  • Assess potential horizontal gene transfer events

• Phylogenetic Profiling

  • Construct phylogenetic trees based on YE2218 sequences

  • Compare with species trees to identify potential lateral gene transfer

  • Correlate with serotype and biotype classifications

These approaches could reveal evolutionary patterns and functional constraints on YE2218, potentially linking its evolution to changes in Yersinia pathogenicity.