Recombinant Saccharomyces cerevisiae Putative uncharacterized protein YGR045C (YGR045C)

What is YGR045C protein in Saccharomyces cerevisiae?

YGR045C is a putative uncharacterized protein found in Saccharomyces cerevisiae (baker's yeast), specifically in the strain ATCC 204508/S288c. The protein consists of 120 amino acids with the sequence: MSQITSKGRRILDKKIRTFPVGFTSRKVAGHVLNISPYFLLAFSYAENKGQSAFEEIKGSNVIDMSCVICFNFSCHLFVVIFISRSTETIPTTKLLLSKYIFYCVNALELTLFLSYKSYS . As an uncharacterized protein, its precise biological function remains to be elucidated, but its conservation in yeast suggests it may have an important cellular role. The gene is cataloged in UniProt under the accession number P53229, and is classified as a putative uncharacterized protein .

What expression systems are commonly used for producing recombinant YGR045C?

For producing recombinant YGR045C, several expression systems can be employed:

Based on available literature for similar yeast proteins, E. coli expression systems are commonly used for producing recombinant S. cerevisiae proteins, including YGR045C . For expression in the native organism, vectors utilizing the GAPDH constitutive promoter (such as pGAPZαC) have shown successful expression of recombinant yeast proteins . Selection typically employs auxotrophic markers like URA3 or antibiotic resistance markers such as Zeocin .

How can I verify successful expression of recombinant YGR045C protein?

Verification of successful YGR045C expression requires multiple complementary techniques:

• PCR Confirmation: Verify genetic integration using gene-specific primers for YGR045C .

• Western Blotting: Detect the expressed protein using:

  • Anti-His-tag antibodies (if the recombinant protein includes a histidine tag)

  • Antibodies against any fusion tags incorporated in the construct

• Immunofluorescence Assay (IFA): Particularly useful for verifying surface display of proteins in yeast systems. Using confocal microscopy with FITC-conjugated secondary antibodies allows visualization of the expressed protein .

• Quantitative Real-Time PCR (qRT-PCR): To assess transcription levels and confirm increased mRNA production in overexpression systems .

A comprehensive verification approach would combine at least two of these methods to confirm both gene presence and protein expression. For example, in studies of recombinant protein expression in S. cerevisiae, researchers often combine PCR verification of gene insertion with Western blotting to confirm protein production .

What genetic manipulation techniques are most effective for overexpressing YGR045C in S. cerevisiae?

For effective overexpression of YGR045C in S. cerevisiae, several genetic manipulation techniques can be employed:

• Plasmid-based Expression:

  • Episomal plasmids using 2μ-based high-copy vectors for strong expression

  • Selection using complementation markers (e.g., URA3 for ura3 mutant strains)

• Genomic Integration:

  • Linearization of expression constructs with appropriate restriction enzymes (e.g., AvrII)

  • Targeting integration to specific loci using homologous recombination

  • CRISPR/Cas9-mediated integration for precise genomic editing

• Promoter Selection:

  • Constitutive promoters: GAPDH (pTDH3) for continuous strong expression

  • Inducible promoters: GAL1/10 for controlled expression using galactose

• Expression Enhancement Strategies:

  • Incorporation of Kozak consensus sequence for improved translation initiation

  • Addition of epitope tags (His-tag, myc-tag) for detection and purification

  • Surface display using systems like Aga2p fusion for displaying proteins on yeast surface

Based on published research, a particularly effective approach combines linearized plasmids for stable genomic integration with the GAPDH constitutive promoter for strong expression . This methodology has been successfully applied for overexpression of various genes in S. cerevisiae with verification by both PCR and Western blotting.

What purification methods yield the highest purity of recombinant YGR045C?

To achieve high purity of recombinant YGR045C protein, a strategic combination of purification techniques is recommended:

• Affinity Chromatography:

  • If YGR045C is expressed with a His-tag, immobilized metal affinity chromatography (IMAC) using Ni-NTA resins is highly effective

  • Optimization of binding and elution conditions is critical for YGR045C-specific purification

• Size Exclusion Chromatography (SEC):

  • Valuable as a polishing step after initial affinity purification

  • Select appropriate column matrix based on the molecular weight of YGR045C (approximately 13-15 kDa)

• Ion Exchange Chromatography:

  • Based on the theoretical isoelectric point of YGR045C

  • Useful for removing contaminants with different charge properties

• Purification Strategy Development:

  • Analytical-scale purifications to determine the most effective combination of techniques

  • SDS-PAGE and Western blot analysis at each purification stage to track protein recovery and purity

For YGR045C specifically, based on similar recombinant yeast protein purification protocols, a typical high-yield purification workflow would consist of cell lysis, clarification by centrifugation, IMAC purification using the His-tag, followed by SEC as a polishing step . This approach has been shown to yield highly pure protein suitable for functional and structural studies.

What statistical methods are appropriate for analyzing YGR045C expression data?

When analyzing YGR045C expression data, selecting appropriate statistical methods depends on the experimental design and data characteristics:

• For Comparing Expression Levels Between Groups:

  Experimental Design	Data Distribution	Recommended Test
  Two unpaired groups	Normal	Independent samples t-test
  Two unpaired groups	Non-normal	Mann-Whitney U test
  Multiple unpaired groups	Normal	One-way ANOVA with post-hoc tests
  Multiple unpaired groups	Non-normal	Kruskal-Wallis test
  Paired measurements	Normal	Paired samples t-test
  Paired measurements	Non-normal	Wilcoxon signed-rank test

• For Expression Correlation Analysis:

  Data Type	Recommended Method
  Two continuous variables, linear relationship	Pearson's correlation coefficient
  Two continuous variables, non-linear relationship	Spearman's rank correlation
  Multiple variables, potential latent factors	Factor analysis
  Grouping similar expression patterns	Cluster analysis

• Key Statistical Considerations:

  • Assess normality using Shapiro-Wilk or Kolmogorov-Smirnov tests

  • Check for homogeneity of variance using Levene's test

  • Consider appropriate transformations (log, square root) for skewed data

  • Select appropriate sample sizes based on power analysis

Based on established methods in biostatistics, a comprehensive statistical approach would typically involve descriptive statistics (means, standard deviations for normally distributed data; medians, interquartile ranges for non-normal data), followed by appropriate hypothesis testing based on the data distribution and experimental design .

What computational approaches can predict potential functions of YGR045C based on its sequence?

Multiple computational approaches can be employed to predict potential functions of the uncharacterized protein YGR045C:

• Sequence Homology Analysis:

  • BLAST searches against protein databases to identify similar characterized proteins

  • Position-Specific Iterated BLAST (PSI-BLAST) for detecting remote homologs

  • Hidden Markov Model (HMM) searches against protein family databases

• Structural Prediction and Analysis:

  Structural Feature	Prediction Tools	Application for YGR045C
  Secondary structure	PSIPRED, JPred	Identify α-helices and β-sheets
  Transmembrane regions	TMHMM, PHOBIUS	Detect potential membrane associations
  Disorder prediction	PONDR, IUPred	Identify flexible regions
  Tertiary structure	AlphaFold2, I-TASSER	Generate 3D structural models

• Functional Site Prediction:

  • Active site prediction using conservation mapping

  • Post-translational modification site prediction

  • Protein-protein interaction motif identification

• Network-based Approaches:

  • Functional association networks (STRING database)

  • Gene co-expression patterns across conditions

  • Genetic interaction profiles compared to known genes

• Integrative Methods:

  • Combining multiple sources of evidence through machine learning approaches

  • Weighted prediction scoring based on confidence levels

For YGR045C specifically, analysis of its 120-amino acid sequence suggests potential membrane-associated domains and possible binding sites that could be further investigated through targeted experiments . The integration of multiple computational predictions would generate testable hypotheses about its molecular function.

How can CRISPR/Cas9 be utilized to study the function of YGR045C in S. cerevisiae?

CRISPR/Cas9 technology offers powerful approaches to study the function of YGR045C through various genome editing strategies:

• Gene Knockout Analysis:

  • Design guide RNAs (gRNAs) targeting the YGR045C coding sequence

  • Introduce Cas9 and gRNA on plasmids (e.g., using vectors with selectable markers like URA3)

  • Exploit S. cerevisiae's efficient homologous recombination to repair Cas9-induced double-strand breaks

  • Screen for successful knockouts using PCR verification and sequencing

  • Analyze phenotypic changes to infer YGR045C function

• Precise Genetic Modifications:

  • Site-directed mutagenesis to create specific amino acid changes

  • Domain deletions or substitutions to identify functional regions

  • Introduction of early stop codons to create truncated versions

• Tagging Strategies:

  • C-terminal or N-terminal fusion with fluorescent proteins for localization studies

  • Addition of affinity tags for protein-protein interaction studies

• Experimental Design Example for YGR045C Study:

  Step	Procedure	Technical Details
  1. gRNA Design	Select target sequences in YGR045C	20-nt target with PAM (NGG), check for off-targets
  2. Vector Construction	Clone gRNA into Cas9-expressing vector	Use established vectors for yeast CRISPR
  3. Transformation	Transform S. cerevisiae with CRISPR components	Use lithium acetate/PEG method
  4. Donor Template	Design repair template for specific modifications	Include 40-60 bp homology arms
  5. Selection	Select transformants	Use auxotrophic markers or drug resistance
  6. Verification	Confirm edits	PCR, sequencing, Western blotting
  7. Phenotypic Analysis	Characterize mutants	Growth rates, stress responses, omics analyses

Based on established CRISPR/Cas9 protocols in yeast, this approach can achieve high editing efficiency by leveraging S. cerevisiae's robust homologous recombination machinery . The system allows for precise manipulation of YGR045C to elucidate its function through various phenotypic and molecular analyses.

How can I design experiments to identify potential protein-protein interactions of YGR045C?

Designing experiments to identify potential protein-protein interactions (PPIs) of YGR045C requires a multi-faceted approach:

• Yeast Two-Hybrid (Y2H) Screening:

  • Clone YGR045C as a bait fusion with a DNA-binding domain

  • Screen against a prey library of S. cerevisiae proteins fused to activation domains

  • Validate positive interactions using reverse Y2H and control experiments

• Affinity Purification-Mass Spectrometry (AP-MS):

  • Express tagged YGR045C (e.g., TAP-tag, FLAG-tag, or His-tag) in yeast

  • Perform gentle cell lysis to preserve protein complexes

  • Capture YGR045C and associated proteins using affinity purification

  • Identify interacting partners using LC-MS/MS analysis

• Proximity-Based Labeling:

  • Express YGR045C fused to enzymes like BioID or TurboID

  • These enzymes biotinylate proteins in close proximity to YGR045C

  • Purify biotinylated proteins using streptavidin beads

  • Identify labeled proteins by mass spectrometry

• Method Comparison and Selection:

  Method	Advantages	Limitations	Best For
  Y2H	High-throughput screening, in vivo detection	High false positive/negative rates	Initial screening
  AP-MS	Detects native complexes, quantitative	May lose transient interactions	Complex identification
  BioID	Detects weak/transient interactions	May label proteins in proximity but not directly interacting	Neighborhood proteomics
  Co-IP	Validates physiological interactions	Limited to stable interactions	Validation of specific PPIs
  Fluorescence-based methods	Real-time in vivo detection	Requires fluorescent protein fusions	Spatiotemporal analysis

• Validation and Characterization:

  • Reciprocal pull-downs to confirm interactions

  • Deletion mapping to identify interaction domains

  • Functional assays to assess biological relevance

For YGR045C specifically, its relatively small size (120 amino acids) and potential membrane association should be considered when designing interaction studies . A comprehensive approach would begin with high-throughput screening methods followed by validation of promising candidates using orthogonal techniques.

What are the optimal storage conditions for recombinant YGR045C protein?

Based on available information about recombinant yeast proteins, including YGR045C, optimal storage conditions are:

• Short-term Storage: Store working aliquots at 4°C for up to one week to maintain protein stability while allowing convenient access for ongoing experiments .

• Medium-term Storage: Store at -20°C in a storage buffer containing Tris-based buffer with 50% glycerol, which helps prevent freeze-thaw damage and maintains protein solubility .

• Long-term Storage: For extended storage periods, conserve samples at -80°C to minimize degradation and preserve protein integrity .

• Important Storage Practices:

  • Divide the purified protein into small single-use aliquots to avoid repeated freeze-thaw cycles

  • Include protease inhibitors in the storage buffer if degradation is observed

  • Monitor protein stability over time using analytical techniques such as SDS-PAGE

  • Avoid repeated freezing and thawing as this can lead to protein denaturation and loss of activity

These recommendations are based on standard practices for similar recombinant proteins and the specific information available for YGR045C from commercial providers and research protocols.

What are the challenges in crystallizing recombinant YGR045C for structural studies?

Crystallizing recombinant YGR045C for structural studies presents several significant challenges:

• Protein Production and Stability Challenges:

  • Potential membrane-associated nature: Based on sequence analysis, YGR045C may have membrane-associated regions, complicating expression and purification

  • Protein yield: Obtaining sufficient quantities (typically 5-10 mg of highly pure protein) for crystallization trials

  • Protein stability: Ensuring long-term stability during the crystallization process

• Crystallization Process Challenges:

  • Finding optimal crystallization conditions: As an uncharacterized protein, YGR045C has no precedent conditions to start from

  • Protein flexibility: Any disordered regions can hinder crystal formation

  • Post-translational modifications: Differences between native and recombinant systems may affect structure

• Strategic Approaches to Address These Challenges:

  Challenge	Strategy	Implementation
  Membrane association	Detergent screening	Test multiple detergent types for solubilization
  Conformational heterogeneity	Construct optimization	Create truncated versions removing flexible regions
  Crystallization conditions	High-throughput screening	Utilize commercial sparse matrix screens
  Crystal quality	Additive screening	Test small molecules that may stabilize crystal contacts
  Phase determination	Heavy atom derivatives	Incorporate selenomethionine for MAD/SAD phasing

• Alternative Structural Approaches:

  • Nuclear Magnetic Resonance (NMR): For solution structure if crystallization proves challenging

  • Cryo-Electron Microscopy: Especially valuable if YGR045C forms larger complexes

  • Small-Angle X-ray Scattering (SAXS): For low-resolution envelope of protein shape

Given YGR045C's small size (120 amino acids) , a successful approach might involve expressing it with fusion tags that facilitate crystallization or exploring co-crystallization with potential binding partners if identified through interaction studies.

What advanced analytical techniques can resolve conflicting functional data about YGR045C?

Resolving conflicting functional data about YGR045C requires sophisticated analytical techniques and integrative approaches:

• Multi-Omics Integration Strategies:

  • Combine transcriptomics, proteomics, metabolomics, and phenomics data

  • Apply network analysis to identify consistent functional signatures across datasets

  • Use machine learning methods to weigh evidence from conflicting sources

• Advanced Genetic Approaches:

  • Synthetic Genetic Array (SGA) Analysis: Systematic creation of double mutants to map genetic interaction networks

  • CRISPR interference/activation (CRISPRi/CRISPRa): Modulate YGR045C expression rather than complete knockout

  • Allelic series: Create multiple variants with different levels of function

• High-Resolution Phenotypic Profiling:

  Technique	Application	Resolution of Conflicts
  Single-cell RNA-seq	Cell-specific responses	Reveals cell-to-cell variability masked in bulk analysis
  Chemogenomic profiling	Drug sensitivity patterns	Links function to specific cellular pathways
  High-content imaging	Subcellular phenotypes	Detects subtle morphological effects missed in growth assays
  Metabolic flux analysis	Metabolic function	Distinguishes direct vs. indirect metabolic effects

• Time-Resolved Experimental Approaches:

  • Temporal profiling of responses after YGR045C perturbation

  • Microfluidics-based single-cell tracking over time

  • These approaches can distinguish primary from secondary effects, resolving apparent conflicts

• Advanced Statistical and Data Analysis Methods:

  • Meta-analysis of multiple independent datasets

  • Principal Component Analysis (PCA) to identify major sources of variation

  • Factor analysis to identify underlying patterns in complex datasets

  • Causal inference modeling to distinguish correlation from causation

By combining these advanced techniques and applying rigorous statistical analysis , researchers can resolve seemingly conflicting data and develop a unified model of YGR045C function. The key is to distinguish between direct and indirect effects, identify condition-specific functions, and determine the cellular context in which different activities predominate.