Recombinant Schizosaccharomyces pombe UPF0742 protein PB2B2.17c (SPBPB2B2.17c)

What is the structural composition of Schizosaccharomyces pombe UPF0742 protein?

The Schizosaccharomyces pombe UPF0742 protein is a full-length protein comprising 146 amino acids based on sequence analysis . Like other UPF (Uncharacterized Protein Family) proteins, it contains conserved domains characteristic of this protein family. For experimental analysis, researchers typically use recombinant versions expressed in E. coli systems with His-tag modifications to facilitate purification through affinity chromatography . The protein's secondary structure prediction suggests a combination of alpha-helices and beta-sheets, though high-resolution structural data through X-ray crystallography or NMR would be necessary for definitive structural characterization.

How does Schizosaccharomyces pombe UPF0742 protein expression vary across cell cycle phases?

Cell cycle-dependent expression of S. pombe UPF0742 protein requires time-course experiments coupled with either Western blot analysis or fluorescence microscopy if using tagged versions of the protein. Recent proteome-scale studies of the fission yeast Schizosaccharomyces pombe based on ORFeome cloning have revealed temporal expression patterns of numerous proteins . To determine expression variations across cell cycle phases, researchers should:

• Synchronize S. pombe cultures using established methods (nitrogen starvation, temperature-sensitive cdc mutants, or elutriation)

• Collect samples at defined time points representing different cell cycle phases

• Extract total protein and quantify UPF0742 protein levels using immunoblotting

• Normalize expression against constitutively expressed control proteins

• Plot relative expression changes across timepoints

What are the most suitable heterologous expression systems for producing recombinant S. pombe UPF0742 protein?

E. coli remains the preferred expression system for S. pombe UPF0742 protein due to its simplicity, cost-effectiveness, and high yield potential . The methodological approach for optimal expression includes:

For most structural and preliminary functional studies, the E. coli system with His-tagging offers the most practical approach, especially when studying the core protein function independent of complex eukaryotic modifications .

What are the optimal buffer conditions for maintaining S. pombe UPF0742 protein stability during purification?

Optimizing buffer conditions is critical for maintaining protein stability throughout the purification process. For S. pombe UPF0742 protein, the following buffer optimization strategy is recommended:

• Lysis Buffer: 50 mM Tris-HCl (pH 7.5-8.0), 300 mM NaCl, 10% glycerol, 1 mM DTT, 1 mM PMSF, and protease inhibitor cocktail

• Wash Buffer: 50 mM Tris-HCl (pH 7.5-8.0), 300 mM NaCl, 20 mM imidazole, 10% glycerol

• Elution Buffer: 50 mM Tris-HCl (pH 7.5-8.0), 300 mM NaCl, 250 mM imidazole, 10% glycerol

• Storage Buffer: 20 mM Tris-HCl (pH 7.5), 150 mM NaCl, 1 mM DTT, 10% glycerol

A thermal shift assay (Differential Scanning Fluorimetry) should be employed to determine optimal pH and salt concentration for maximum stability. Given that S. pombe proteins often exhibit specific requirements for stability, systematic testing of additives such as reducing agents (DTT, β-mercaptoethanol), stabilizers (glycerol, trehalose), and metal ions (particularly in relation to iron regulation systems as seen in other S. pombe proteins ) is essential for developing a robust purification protocol.

How can I design effective co-immunoprecipitation experiments to identify interaction partners of S. pombe UPF0742 protein?

To identify interaction partners of S. pombe UPF0742 protein through co-immunoprecipitation, implement the following methodological approach:

• Express tagged UPF0742 protein in S. pombe using either endogenous tagging or controlled expression systems

• Choose appropriate tags (FLAG, HA, or GFP) based on available antibodies and interference with protein function

• Prepare cell lysates under mild conditions to preserve protein-protein interactions:

  • Buffer composition: 20 mM HEPES (pH 7.4), 150 mM NaCl, 0.1% NP-40, 1 mM EDTA, 10% glycerol, with protease and phosphatase inhibitors

  • Gentle lysis using glass beads or enzymatic methods

• Perform immunoprecipitation using antibody-conjugated beads specific to the chosen tag

• Include appropriate controls:

  • Negative control: untagged strain processed identically

  • Bead-only control: beads without antibody

  • Input sample: total lysate before immunoprecipitation

• Analyze co-precipitated proteins by:

  • Western blotting for suspected interactors

  • Mass spectrometry for unbiased discovery of novel interactors

• Validate interactions using reciprocal co-IP or other interaction verification methods

This approach can reveal potential functional associations in iron regulation networks or other cellular processes, similar to those observed with other S. pombe proteins like Grx4, Fep1, and Php4 .

What approaches are most effective for analyzing the subcellular localization of S. pombe UPF0742 protein?

For comprehensive subcellular localization analysis of S. pombe UPF0742 protein, combine multiple complementary approaches:

• Fluorescence Microscopy-Based Methods:

  • Endogenous tagging with fluorescent proteins (GFP, mCherry)

  • Create C-terminal or N-terminal fusions depending on predicted structure

  • Include co-localization with known organelle markers

  • Perform time-lapse imaging across the cell cycle

• Biochemical Fractionation:

  • Differential centrifugation to separate organelles

  • Density gradient separation for finer resolution

  • Western blot analysis of fractions using antibodies against the protein and organelle markers

• Immunoelectron Microscopy:

  • Ultra-structural localization at nanometer resolution

  • Use gold-conjugated antibodies against tags or the native protein

• Proximity-Dependent Labeling:

  • BioID or APEX2 fusion to identify neighboring proteins in the same subcellular compartment

  • Mass spectrometry analysis of biotinylated proteins

When designing these experiments, consider how localization might change under different conditions, especially under varying iron concentrations, given the role of related S. pombe proteins in iron homeostasis .

How does the function of S. pombe UPF0742 protein relate to iron homeostasis in comparison to characterized regulators like Grx4, Fep1, and Php4?

While direct evidence for UPF0742 protein involvement in iron homeostasis is not explicitly stated in the search results, comparative analysis with better-characterized S. pombe proteins can guide hypotheses and experimental design:

S. pombe utilizes an integrated system for iron regulation involving Grx4, Fep1, and Php4 . To investigate potential involvement of UPF0742 protein in this pathway:

• Conduct expression analysis to determine if UPF0742 protein levels change in response to iron availability, similar to established iron-responsive proteins

• Perform phenotypic analysis of deletion mutants under varying iron conditions

• Use ChIP-seq to identify potential DNA binding sites if DNA-binding domains are predicted

• Employ protein-protein interaction studies to detect associations with known iron regulatory proteins

A methodological approach to determine functional relationships would include:

This systematic approach would help position UPF0742 protein within the iron regulatory network, if applicable .

What computational approaches can predict functional domains in S. pombe UPF0742 protein when crystallographic data is unavailable?

In the absence of crystallographic data, several computational approaches can predict functional domains and generate testable hypotheses:

• Sequence-Based Predictions:

  • Multiple sequence alignment with homologs across species

  • Identification of conserved motifs using MEME, PROSITE, or Pfam

  • Disorder prediction using IUPred2 or PONDR

  • Secondary structure prediction using PSIPRED or JPred

• 3D Structure Prediction:

  • Template-based modeling using tools like I-TASSER, SWISS-MODEL

  • Deep learning approaches like AlphaFold2 or RoseTTAFold

  • Molecular dynamics simulations to assess structure stability

• Function Prediction:

  • Gene Ontology term prediction

  • Protein-protein interaction prediction

  • Ligand binding site prediction using CASTp or 3DLigandSite

• Integrative Approaches:

  • Combined analysis of genomic context, phylogenetic profiling

  • Co-expression data analysis

  • Text mining of scientific literature

These computational predictions should be verified through systematic experimental validation, including site-directed mutagenesis of predicted functional residues, domain deletion studies, and interactome analysis, similar to approaches used in the bioinformatics analysis of other S. pombe proteins .

How can CRISPR-Cas9 genome editing be optimized for studying S. pombe UPF0742 protein function in vivo?

Optimizing CRISPR-Cas9 genome editing for S. pombe requires addressing several fission yeast-specific considerations:

• Guide RNA Design:

  • Select target sites with minimal off-target potential using S. pombe-specific algorithms

  • Consider GC content (30-70%) for optimal guide efficiency

  • Avoid regions with secondary structures that might impair guide functionality

  • Target conserved domains identified through comparative genomics

• Delivery System Optimization:

  • Episomal expression using pREP-based vectors with appropriate promoter strength

  • Integration of Cas9 at safe harbor loci for stable expression

  • Optimal codon optimization for S. pombe expression systems

• Repair Template Design:

  • Homology arms of 500-1000 bp for efficient homology-directed repair

  • Include silent mutations in the PAM site to prevent re-cutting

  • Consider using selectable markers flanked by loxP sites for marker recycling

• Verification Strategies:

  • PCR-based genotyping with primers spanning expected modification sites

  • Sequencing to confirm precise edits

  • Western blotting to verify protein expression changes

  • Phenotypic analysis under conditions relevant to hypothesized function

A systematic approach comparing editing efficiency across different experimental conditions (temperature, transformant selection time, guide RNA structure) will help establish an optimized protocol specific to the genomic context of the UPF0742 protein locus.

How can I resolve inconsistent expression levels of recombinant S. pombe UPF0742 protein in E. coli systems?

Inconsistent expression of recombinant S. pombe UPF0742 protein in E. coli can be methodically addressed through the following troubleshooting approach:

• Codon Optimization Analysis:

  • Analyze codon usage bias between S. pombe and E. coli

  • Consider synthesizing a codon-optimized gene for E. coli expression

  • Co-express rare tRNAs using specialized strains like Rosetta or CodonPlus

• Expression Conditions Optimization:

  • Systematically test induction parameters (temperature, IPTG concentration, induction time)

  • Screen multiple E. coli strains (BL21(DE3), Arctic Express, C41/C43)

  • Implement auto-induction media formulations

• Protein Stability Enhancement:

  • Co-express molecular chaperones (GroEL/GroES, DnaK/DnaJ)

  • Add stabilizing fusion partners (MBP, SUMO, Thioredoxin)

  • Include appropriate protease inhibitors throughout purification

• Solubility Improvement:

  • Test detergents for membrane protein extraction if applicable

  • Implement on-column refolding protocols

  • Consider dual-tagging strategies for improved purification

The recombinant production of His-tagged S. pombe UPF0742 protein has been achieved in E. coli systems , suggesting that with proper optimization, consistent expression is achievable.

What are the potential explanations for differential phenotypes observed between UPF0742 protein deletion mutants and RNAi knockdown experiments?

Differential phenotypes between deletion mutants and RNAi knockdown of UPF0742 protein may arise from several mechanistic differences that should be systematically evaluated:

• Temporal Differences:

  • Deletion mutants represent constitutive absence from embryonic stages

  • RNAi creates acute depletion in developmentally mature cells

  • Design time-course experiments with inducible deletion systems to distinguish developmental from direct effects

• Compensation Mechanisms:

  • Long-term absence in deletion mutants may trigger genetic compensation

  • Identify potential compensatory pathways through transcriptome analysis of deletion vs. knockdown strains

  • Test double mutants of UPF0742 with predicted compensatory genes

• Knockdown Efficiency and Specificity:

  • Quantify residual protein levels in RNAi experiments

  • Assess potential off-target effects through transcriptome analysis

  • Implement multiple RNAi constructs targeting different regions of the transcript

• Contextual Differences:

  • Evaluate strain background effects and genetic interactions

  • Examine phenotypes under various environmental stresses

  • Consider cell-type specific effects if relevant

This analytical approach helps distinguish technical artifacts from biologically meaningful differences in protein function and cellular adaptation mechanisms.

How can I integrate proteomic and transcriptomic data to build a comprehensive functional model of S. pombe UPF0742 protein?

Integrating proteomic and transcriptomic data for functional modeling of S. pombe UPF0742 protein requires a multi-layered analytical approach:

• Data Integration Framework:

  • Perform differential expression analysis at both transcript and protein levels

  • Calculate correlation coefficients between transcriptomic and proteomic changes

  • Apply normalization techniques suitable for cross-platform integration

  • Implement statistical methods to handle missing values and different dynamic ranges

• Network Analysis:

  • Construct protein-protein interaction networks incorporating UPF0742

  • Identify enriched pathways and biological processes using GO term analysis

  • Apply machine learning algorithms to predict functional associations

  • Compare network topology with those of characterized proteins like Fep1 and Php4

• Temporal and Condition-Specific Analysis:

  • Analyze dynamic changes across different conditions (stress, cell cycle phases)

  • Identify condition-specific interaction partners and expression patterns

  • Apply time-series analysis for temporal data

• Experimental Validation Framework:

  • Design targeted experiments to validate key predictions

  • Implement CRISPR screening to systematically test genetic interactions

  • Use proximity labeling approaches to validate predicted protein associations

This integrated approach has been successfully implemented in proteome-scale studies of S. pombe , and can effectively position UPF0742 protein within the broader functional context of fission yeast cellular processes.

What emerging technologies show promise for elucidating the function of uncharacterized proteins like S. pombe UPF0742?

Several cutting-edge technologies can accelerate functional characterization of uncharacterized proteins like S. pombe UPF0742:

• Proximity-Dependent Labeling Technologies:

  • BioID, TurboID, or APEX2 fusion constructs to identify proximal proteins

  • Integration with mass spectrometry for spatial proteomics

  • Application across various cellular conditions to map dynamic interactomes

• Single-Cell Approaches:

  • Single-cell RNA-seq to identify cell-type specific expression patterns

  • Single-cell proteomics to detect protein abundance variations

  • Correlation with phenotypic data for functional inference

• Cryo-Electron Microscopy:

  • High-resolution structural determination without crystallization

  • Visualization of protein complexes in near-native states

  • Integration with computational modeling for complete structural characterization

• High-Throughput Functional Screens:

  • CRISPR activation/inhibition screens for genetic interactions

  • Synthetic genetic array analysis adapted for S. pombe

  • Chemical-genetic interaction profiling

These technologies can be particularly valuable for positioning UPF0742 protein within the context of known regulatory networks in S. pombe, such as the iron homeostasis system involving Grx4, Fep1, and Php4 .

How can evolutionary analysis of UPF0742 protein homologs across fungal species inform functional hypotheses?

Evolutionary analysis of UPF0742 protein across fungal species provides valuable insights for functional hypothesis generation:

• Phylogenetic Profiling Approach:

  • Construct comprehensive phylogenetic trees of UPF0742 homologs

  • Map presence/absence patterns across diverse fungal lineages

  • Correlate with emergence of specific cellular processes or environmental adaptations

• Sequence Conservation Analysis:

  • Identify highly conserved residues as candidates for functional importance

  • Analyze conservation patterns in predicted structural domains

  • Compare conservation profiles with proteins of known function

• Co-evolution Network Construction:

  • Identify proteins with similar phylogenetic profiles

  • Detect correlated evolutionary changes suggesting functional relationships

  • Map potential interactions with iron regulatory proteins across species

• Comparative Genomic Context Analysis:

  • Examine synteny and gene neighborhood across fungal genomes

  • Identify consistently co-located genes suggesting functional relationships

  • Compare with genomic organization of characterized proteins

This evolutionary approach complements the bioinformatics analysis methods used for other S. pombe proteins and their homologs in species like Aspergillus flavus and Saccharomyces cerevisiae , potentially revealing functional connections not apparent from direct experimental approaches.