Recombinant Saccharomyces cerevisiae Uncharacterized protein YBR219C (YBR219C)

What is YBR219C and where is it found?

YBR219C is an uncharacterized protein encoded by the Saccharomyces cerevisiae genome (strain ATCC 204508 / S288c) . The protein is 127 amino acids in length with the following sequence: MTLLNTLSNFGGTWPRLIIMSMINYFTVYQCTIPGTNKVYVTHGGSMQACTELLNGTVTILRDGYYITNLICIVVGLFLYFGYLKRKILHLQSLPISSWRFFHFFFTILAVTSRAIYYKSQNWRREC . Despite being classified as "uncharacterized," YBR219C has been identified in extracellular vesicles derived from Saccharomyces cerevisiae, suggesting potential roles in intercellular communication or metabolite transport .

To study YBR219C localization, researchers can employ fluorescent protein tagging approaches. GFP fusion proteins can be created using homologous recombination techniques, where the GFP coding sequence is integrated in-frame with the YBR219C gene. Subsequent confocal microscopy can reveal subcellular localization patterns under various growth conditions or stress states.

What databases contain information about YBR219C?

YBR219C is cataloged in several specialized databases focusing on extracellular vesicles and yeast genetics. The protein is indexed in Vesiclepedia (VP_852520), EV Quant (EVQuant_852520), ExoCarta (ExoCarta_852520), and Entrez Gene (852520) . These databases provide valuable resources for researchers investigating YBR219C's potential involvement in vesicle-mediated processes.

When conducting literature reviews or bioinformatic analyses, researchers should query these specialized databases rather than relying solely on general protein databases. This approach ensures comprehensive coverage of vesicle-specific data and contextual information relevant to YBR219C function. Cross-referencing findings between these databases can help identify consistent patterns in YBR219C expression, modification, or interaction data.

How can I obtain recombinant YBR219C protein for experimental studies?

Recombinant YBR219C protein can be obtained through commercial sources or produced in-house using expression systems. Commercial recombinant protein is available as ELISA-compatible preparations, typically supplied in Tris-based buffer with 50% glycerol optimized for stability . For in-house production, the gene can be PCR-amplified from S. cerevisiae genomic DNA and cloned into appropriate expression vectors.

For expression system selection, consider that YBR219C is a yeast protein that may require eukaryotic post-translational modifications. While E. coli systems offer high yield and simplicity, they may not reproduce native folding or modifications. Pichia pastoris or baculovirus-insect cell systems may provide better structural fidelity. Purification can be facilitated by incorporating affinity tags like His6 or GST, followed by tag removal if necessary for functional studies. Quality control should include SDS-PAGE, western blotting, and mass spectrometry to confirm integrity and purity.

What experimental approaches are suitable for studying YBR219C function?

Given YBR219C's uncharacterized status, multiple complementary approaches should be employed to elucidate its function:

• Gene deletion/knockout studies: The YBR219C gene can be deleted using homologous recombination techniques, and the resulting phenotypes can be assessed under various conditions. This approach has already revealed a relationship between YBR219C deletion and hygromycin B resistance .

• Protein localization studies: Fluorescent protein tagging can determine subcellular localization patterns.

• Protein interaction studies: Techniques such as yeast two-hybrid, co-immunoprecipitation, or proximity labeling methods (BioID, APEX) can identify interaction partners.

• Transcriptomic and proteomic profiling: Compare wild-type and YBR219C deletion strains to identify affected pathways.

• Structural studies: X-ray crystallography or cryo-electron microscopy can provide insights into protein function based on structure.

The multi-omics approach is particularly valuable for uncharacterized proteins, as it can reveal functional relationships within cellular networks even without prior knowledge of biochemical activity.

How does YBR219C deletion contribute to hygromycin B resistance?

The deletion of YBR219C has been shown to confer a small but noticeable improvement in hygromycin B resistance in S. cerevisiae . This finding emerged from SCRaMbLE (Synthetic Chromosome Rearrangement and Modification by LoxP-mediated Evolution) experiments aimed at generating hygromycin B resistant phenotypes. The exact molecular mechanism for this resistance remains uncharacterized, but several hypotheses can be proposed:

To investigate these hypotheses, researchers should consider:

• Conducting RNA-seq analysis comparing wild-type and YBR219C deletion strains with and without hygromycin B treatment to identify differentially expressed genes.

• Performing metabolomic analysis to detect changes in cellular metabolites that might indicate altered stress response pathways.

• Measuring intracellular accumulation of hygromycin B to determine if deletion affects antibiotic uptake or efflux.

• Examining polysome profiles to assess translation efficiency and fidelity in the presence of hygromycin B.

Notably, while the single deletion of YBR219C increases resistance, the double deletion of YBR219C and YBR220C results in severe growth defects even under standard conditions , suggesting complex genetic interactions that warrant further investigation.

What are the structural features of YBR219C that might inform its function?

While experimental structural data for YBR219C is limited, computational analysis of its amino acid sequence can provide valuable insights into potential structural features and functional domains.

The YBR219C protein sequence (MTLLNTLSNFGGTWPRLIIMSMINYFTVYQCTIPGTNKVYVTHGGSMQACTELLNGTVTILRDGYYITNLICIVVGLFLYFGYLKRKILHLQSLPISSWRFFHFFFTILAVTSRAIYYKSQNWRREC) suggests several notable characteristics:

• Hydrophobicity pattern analysis indicates multiple hydrophobic regions that could represent transmembrane domains, consistent with membrane localization.

• The sequence contains potential protein-protein interaction motifs, including leucine-rich segments.

• Secondary structure prediction suggests a mix of alpha-helical and beta-sheet regions.

For experimental structure determination, researchers should consider:

• X-ray crystallography following optimization of protein expression and purification conditions

• NMR spectroscopy for solution structure, particularly suitable if YBR219C is relatively small and soluble

• Cryo-electron microscopy if YBR219C forms part of a larger complex

• Hydrogen-deuterium exchange mass spectrometry to identify flexible and surface-exposed regions

Structural information would significantly advance understanding of YBR219C function, potentially revealing binding pockets or interaction surfaces that could explain its role in hygromycin B resistance.

How does YBR219C relate to extracellular vesicle formation in yeast?

YBR219C has been identified in extracellular vesicles derived from Saccharomyces cerevisiae , suggesting a potential role in vesicle formation, cargo loading, or vesicle function. Extracellular vesicles in yeast are involved in various processes including cell-to-cell communication, export of waste products, and response to environmental stresses.

To investigate YBR219C's role in extracellular vesicles, researchers should consider:

• Comparative proteomics of extracellular vesicles from wild-type and YBR219C deletion strains to identify changes in vesicle protein composition.

• Analysis of vesicle size distribution, morphology, and abundance using nanoparticle tracking analysis, electron microscopy, and flow cytometry.

• Functional assays to determine if vesicles from YBR219C deletion strains have altered biological activities when applied to recipient cells.

• Co-localization studies with known extracellular vesicle markers to determine if YBR219C is involved in specific vesicle subtypes.

The connection between YBR219C's presence in extracellular vesicles and its role in hygromycin B resistance is particularly intriguing. Extracellular vesicles have been implicated in antibiotic resistance mechanisms in other organisms, suggesting that YBR219C might influence resistance through vesicle-mediated processes.

What genetic interactions does YBR219C participate in?

Understanding the genetic interaction landscape of YBR219C is crucial for placing it within cellular pathways and networks. Several approaches can reveal these interactions:

• Synthetic genetic array (SGA) analysis: By crossing a YBR219C deletion strain with the yeast deletion collection, researchers can identify genes that show synthetic lethality or synthetic growth defects when simultaneously deleted with YBR219C.

• Synthetic dosage lethality (SDL) screens: Overexpression of YBR219C in the background of other gene deletions can reveal genes whose function becomes essential when YBR219C is upregulated.

• Multi-deletion phenotyping: The observation that YBR219C and YBR220C double deletion causes severe growth defects already indicates one important genetic interaction. Systematic creation of double and triple mutants with genes in related pathways can expand this network.

• Transcriptome analysis: RNA-seq comparisons between wild-type and YBR219C deletion strains can identify compensatory transcriptional responses that suggest functional relationships.

The severe growth defect in the YBR219C/YBR220C double deletion strain, despite each single deletion being viable, suggests that these genes might have partially redundant functions or affect parallel pathways that are collectively essential . This represents a promising starting point for deeper genetic interaction studies.

How can SCRaMbLE technology be leveraged to further study YBR219C function?

The SCRaMbLE (Synthetic Chromosome Rearrangement and Modification by LoxP-mediated Evolution) technology has already proven valuable in identifying YBR219C's role in hygromycin B resistance . This approach can be further exploited to investigate other aspects of YBR219C function through the following strategies:

• Directed evolution under various selective pressures: Apply SCRaMbLE to synthetic yeast strains under different stress conditions (temperature, pH, other antibiotics, osmotic stress) to determine if YBR219C deletion consistently emerges as an adaptive response.

• Combinatorial genetic modifications: Use SCRaMbLE to generate complex rearrangements involving YBR219C and analyze which combinations enhance or suppress specific phenotypes.

• Pathway mapping: Subject YBR219C-related pathways to SCRaMbLE and analyze which other genes in the pathway are frequently modified together with YBR219C.

• Functional domain identification: Design synthetic chromosomes with loxP sites positioned within the YBR219C gene to enable SCRaMbLE-mediated domain shuffling or truncation, potentially revealing functional regions within the protein.

The advantage of SCRaMbLE is its ability to generate complex structural variations beyond simple gene deletions, potentially revealing emergent properties that cannot be observed through traditional single-gene approaches . Researchers should leverage nanopore sequencing for accurate characterization of the resulting genomic arrangements, as demonstrated in previous SCRaMbLE studies .

What is the optimal approach for generating and validating YBR219C deletion strains?

Creating precise YBR219C deletion strains is fundamental to functional studies. The recommended approach combines traditional homologous recombination with verification protocols:

• Deletion cassette design:

  • Design primers with 40-50bp homology to regions flanking YBR219C

  • Amplify a selection marker (e.g., KanMX for G418 resistance)

  • Include unique barcode sequences for strain identification

• Transformation and selection:

  • Transform S. cerevisiae with the deletion cassette using lithium acetate method

  • Select transformants on appropriate antibiotic media

  • Isolate single colonies for verification

• Comprehensive verification protocols:

  • PCR confirmation using primers outside the deletion cassette

  • Quantitative PCR to ensure complete deletion

  • Whole genome sequencing to rule out off-target effects or compensatory mutations

• Phenotypic validation:

  • Compare growth rates under standard conditions

  • Assess hygromycin B resistance (expected to increase)

  • Examine extracellular vesicle production

For researchers specifically interested in the hygromycin B resistance phenotype, verification should include dose-response assays with hygromycin B concentrations ranging from 100-300 μg/mL, as previous studies identified resistance improvements at approximately 250 μg/mL .

How should experiments be designed to investigate YBR219C's role in extracellular vesicles?

To systematically investigate YBR219C's role in extracellular vesicle biology, a comprehensive experimental design should include:

• Extracellular vesicle isolation:

  • Grow wild-type and YBR219C deletion strains in identical conditions

  • Harvest culture supernatant and remove cells by differential centrifugation

  • Isolate extracellular vesicles using ultracentrifugation, density gradient separation, or size exclusion chromatography

  • Verify vesicle purity by nanoparticle tracking analysis and electron microscopy

• Comparative vesicle characterization:

  • Quantify vesicle yield (number and total protein content)

  • Determine size distribution profiles

  • Analyze lipid composition by mass spectrometry

  • Perform proteomic analysis of vesicle cargo

• Functional assessment:

  • Evaluate vesicle uptake by recipient cells

  • Assess changes in recipient cell phenotypes (growth, stress resistance)

  • Measure transfer of specific cargo molecules

• Mechanistic investigations:

  • Use fluorescently tagged YBR219C to track its incorporation into vesicles

  • Identify YBR219C interaction partners during vesicle formation

  • Analyze the effects of YBR219C overexpression on vesicle production

This multifaceted approach will provide insights into whether YBR219C functions in vesicle biogenesis, cargo selection, or vesicle function, while establishing connections between these roles and the observed hygromycin B resistance phenotype .

What controls and variables should be considered when studying YBR219C's role in hygromycin B resistance?

Designing rigorous experiments to investigate YBR219C's contribution to hygromycin B resistance requires careful consideration of controls and variables:

Essential controls:

• Parental strain (wild-type) without modifications

• Known hygromycin B resistant strain as positive control

• Single gene deletion strains of neighboring genes (e.g., YBR220C)

• Complementation strain (YBR219C deletion with reintroduced YBR219C gene)

• Strain with deletion of a gene unrelated to stress response

Key variables to consider:

• Hygromycin B concentration range (50-300 μg/mL)

• Growth phase during treatment (log, stationary)

• Growth media composition (rich vs. minimal)

• Temperature and pH conditions

• Duration of hygromycin B exposure

Experimental readouts:

• Growth curves in liquid culture with hygromycin B

• Spot assays on solid media with increasing hygromycin B concentrations

• Minimum inhibitory concentration (MIC) determination

• Time-kill kinetics

• Microscopic assessment of cell morphology during treatment

Previous research indicates that the YBR219C deletion strain shows approximately 40% improvement in hygromycin B resistance compared to the parental strain, with growth observed at concentrations up to 250 μg/mL . Researchers should design experiments with sufficient statistical power to detect differences of this magnitude, typically requiring at least 3-5 biological replicates and 2-3 technical replicates per condition.

How should researchers interpret conflicting data regarding YBR219C function?

When facing conflicting data about YBR219C function, researchers should implement a systematic approach to data reconciliation:

• Context evaluation:

  • Assess experimental conditions (strain backgrounds, growth conditions, assay methods)

  • Consider genetic background effects (synthetic vs. natural chromosomes)

  • Evaluate methodology sensitivity and specificity

• Data integration framework:

  • Develop a hierarchical model prioritizing direct experimental evidence

  • Apply Bayesian analysis to weight contradictory findings based on experimental rigor

  • Construct alternative hypotheses that could explain divergent results

• Resolution strategies:

  • Design critical experiments specifically addressing contradictions

  • Implement orthogonal methods to validate key findings

  • Collaborate with labs reporting conflicting results to standardize protocols

For example, the observed hygromycin B resistance in YBR219C deletion strains might appear to conflict with growth defects in double deletion strains (YBR219C and YBR220C) . These findings can be reconciled by considering that YBR219C may participate in multiple cellular processes with context-dependent effects. The resistance phenotype may reflect altered membrane permeability or stress response pathways, while growth defects in the double mutant suggest functional redundancy with YBR220C in essential processes.

What bioinformatic approaches are most valuable for analyzing YBR219C?

Given YBR219C's uncharacterized status, computational analyses can provide valuable functional insights. The following bioinformatic approaches are particularly valuable:

• Homology-based analyses:

  • PSI-BLAST searches against diverse organisms to identify distant homologs

  • HHpred for detecting remote homology through profile-profile comparisons

  • Phylogenetic profiling to identify co-evolving genes

• Structural prediction:

  • AlphaFold2 or RoseTTAFold for ab initio structure prediction

  • Molecular dynamics simulations to identify stable conformations

  • Binding site prediction tools to suggest potential ligands

• Network analyses:

  • Integration of protein-protein interaction data

  • Co-expression network analysis across diverse conditions

  • Functional association networks (STRING database)

• Biological process prediction:

  • Gene Ontology term enrichment among interaction partners

  • Metabolic pathway analysis for genes showing synthetic interactions

  • Regulatory motif analysis in the promoter region

A particularly informative approach would be to compare YBR219C with YBR220C, given their genetic interaction . Structural predictions might reveal shared domains or binding motifs that explain their functional relationship, while network analyses could identify common interaction partners that shed light on their redundant functions.

What are the most promising future research directions for YBR219C?

Based on current knowledge about YBR219C, several high-priority research directions emerge:

• Mechanistic investigation of hygromycin B resistance:

  • Determine if resistance involves altered drug uptake, efflux, or target modification

  • Identify specific cellular pathways affected by YBR219C deletion that contribute to resistance

  • Explore potential applications in developing novel antibiotic resistance mechanisms

• Extracellular vesicle biology:

  • Characterize YBR219C's role in vesicle formation, cargo loading, or release

  • Investigate if vesicle-associated functions relate to stress response mechanisms

  • Explore potential roles in cell-to-cell communication

• Structural biology:

  • Determine three-dimensional structure through crystallography or cryo-EM

  • Identify functional domains and potential binding partners

  • Design structure-guided mutations to test functional hypotheses

• Systems biology approach:

  • Map the complete genetic interaction network surrounding YBR219C

  • Perform multi-omics analysis (transcriptomics, proteomics, metabolomics) in various conditions

  • Develop predictive models of YBR219C function within cellular networks

• Evolutionary analysis:

  • Compare YBR219C function across different yeast species

  • Identify selection pressures that maintain this gene

  • Investigate potential horizontal gene transfer events

The connection between YBR219C deletion and hygromycin B resistance represents a particularly promising avenue for investigation, as it provides a clear phenotype for further mechanistic studies and potential biotechnological applications .

How can findings about YBR219C be integrated with broader yeast biology research?

YBR219C research has implications that extend beyond understanding this specific protein:

• Antibiotic resistance mechanisms:

  • Findings may reveal novel mechanisms of resistance applicable to other antibiotics

  • Could inform strategies for combating resistance in pathogenic fungi

  • May provide insights into fundamental cellular processes targeted by antibiotics

• Synthetic biology applications:

  • YBR219C modifications could be incorporated into engineered yeast strains for biotechnology

  • Findings from SCRaMbLE studies demonstrate the value of genome restructuring approaches

  • May inspire new synthetic genetic circuits incorporating stress response elements

• Extracellular vesicle biology:

  • Contributes to growing understanding of vesicle-mediated communication in unicellular organisms

  • May reveal conserved mechanisms relevant to mammalian extracellular vesicles

  • Could inspire bioengineering approaches for vesicle-based drug delivery

• Uncharacterized proteome exploration:

  • YBR219C research exemplifies approaches for studying the approximately 20% of yeast proteins that remain uncharacterized

  • Methodologies developed can serve as templates for investigating other orphan genes

  • Findings contribute to completeness of yeast as a model organism