Recombinant Schizosaccharomyces pombe Uncharacterized protein C12B10.02c (SPAC12B10.02c)

What is known about the function of SPAC12B10.02c in Schizosaccharomyces pombe?

SPAC12B10.02c is a protein that was previously annotated as essential, but recent genome-wide studies have demonstrated that it is non-essential under standard laboratory conditions. The protein has been identified among 532 genes that contribute to sexual reproduction in S. pombe, with its deletion affecting mating efficiency . The protein contains a transmembrane domain with the sequence "MSNVQRKRIDIRRPTLAELSSIRSIAMNALNGQSRNLSQKIFWHPLYLAVFGLVFMGIYR LTNMVEGNTKLRTFVLLILVSAVFLTLIEFPCRNVYAKISTEDNQPDGCLAEENLKHFYM ARIDKERVIGIIGILPANAPGAYQNTPTIVHWTVIPKFYQYAFDLLDSALREAKEMGADV VSARVYSTDPMLKAFEKKDFTPVVDEAFDYLSFFGLRRLVLQKNLSEQPGFENRR" as indicated in the available amino acid sequence data .

To properly characterize this protein's function, researchers should consider:

• Phenotypic analyses of deletion strains during vegetative growth and sexual reproduction

• Localization studies using fluorescent tags

• Proteomic approaches to identify interaction partners

• Comparative genomics with related species to identify conserved domains

How does SPAC12B10.02c relate to sexual reproduction in fission yeast?

SPAC12B10.02c has been identified as part of a genetic screen for contributors to sexual fitness in S. pombe. In a genome-wide study that quantified contributions to sexual fitness, SPAC12B10.02c was among 532 genes shown to affect sexual reproduction . Importantly, the protein appears to have a specialized role in sexual reproduction rather than general growth, as the deletion strain did not show significant growth impairment before or after the sexual reproduction assay.

When investigating this protein's role in sexual reproduction, researchers should:

• Examine specific stages of the sexual reproduction process (mating, meiosis, sporulation)

• Test the strain under various nutrient conditions that trigger sexual development

• Consider possible molecular functions during nuclear fusion or meiotic divisions

What are the recommended protocols for recombinant expression of SPAC12B10.02c?

Recombinant expression of SPAC12B10.02c can be challenging due to its membrane-associated properties. Based on the available research, the following methodological approach is recommended:

• Expression System Selection:

  • E. coli systems are suitable for partial protein domains

  • Yeast expression systems (P. pastoris or S. cerevisiae) may provide proper folding for the full-length protein

  • Baculovirus expression systems can be used for higher yields of properly folded protein

• Purification Strategy:

  • Use affinity tags (His-tag or GST-tag) positioned to avoid interference with protein folding

  • Include detergent screening (e.g., DDM, LDAO, or Triton X-100) for membrane protein solubilization

  • Consider on-column detergent exchange during purification

• Quality Control:

  • Verify protein purity using SDS-PAGE (≥85% purity as standard)

  • Confirm protein identity via mass spectrometry

  • Assess protein folding through circular dichroism

How should researchers design experiments to investigate the essentiality of SPAC12B10.02c?

The conflicting reports regarding the essentiality of SPAC12B10.02c require careful experimental design to resolve. Based on recent findings that challenge its essential status , researchers should:

• Generate Conditional Mutants:

  • Create repressible promoter constructs (e.g., using nmt81 promoter) similar to approaches used for other genes

  • Develop temperature-sensitive alleles through site-directed mutagenesis

• Validation Methods:

  • Perform tetrad analysis to confirm viability of deletion strains

  • Use PCR and Southern blotting to verify complete gene deletion

  • Conduct complementation tests with wild-type gene

• Growth Condition Variables:

  • Test essentiality under various nutrient conditions, temperatures, and pH levels

  • Examine growth in minimal versus rich media

  • Assess viability during different cell cycle stages

• Control Experiments:

  • Include known essential and non-essential genes as controls

  • Verify strain backgrounds are consistent across experiments

What approaches can be used to identify interacting partners of SPAC12B10.02c?

To comprehensively identify protein interaction partners of SPAC12B10.02c, multiple complementary approaches should be employed:

• Affinity Purification-Mass Spectrometry:

  • Tag the protein with epitopes like HA, FLAG, or TAP tag

  • Consider proximity-dependent biotin identification (BioID) for transient interactions

  • Use cross-linking prior to purification to capture weak interactions

• Yeast Two-Hybrid and Split-Ubiquitin Systems:

  • The split-ubiquitin system is preferable for membrane proteins like SPAC12B10.02c

  • Screen against normalized cDNA libraries or select candidate interactors

  • Validate interactions through reciprocal testing

• Genetic Interaction Screens:

  • Synthetic genetic array (SGA) analysis with SPAC12B10.02c mutants

  • Use both deletion and conditional alleles to capture essential gene interactions

  • Follow methodology similar to that used for btn1 studies

• Data Analysis Pipeline:

  • Filter results based on cellular compartmentalization data

  • Apply stringent statistical thresholds to minimize false positives

  • Integrate with existing protein interaction databases

How can researchers investigate the potential alternative splicing of SPAC12B10.02c during meiosis?

Recent studies have revealed extensive alternative splicing in S. pombe during meiosis . To investigate whether SPAC12B10.02c undergoes alternative splicing:

• Long-Read Sequencing:

  • Use PacBio sequencing for full-length transcript detection

  • Sample multiple timepoints during meiotic progression

  • Compare with RNA-Seq data from vegetative cells

• RT-PCR Validation:

  • Design primers spanning potential splice junctions

  • Use quantitative PCR to measure relative abundance of isoforms

  • Verify novel splice variants by Sanger sequencing

• Functional Characterization of Isoforms:

  • Express individual splice variants and assess functionality

  • Determine subcellular localization of each isoform

  • Test for isoform-specific protein interactions

• Analysis Framework:

  • Apply classification scheme for alternative splicing events as shown in this example table:

  AS Type	Example in S. pombe	Detection Method
  Alternative acceptor	SPCC1281.08	Junction spanning reads
  Exon inclusion	SPBC1703.10	Exon coverage analysis
  Intron retention	SPAPB8E5.05	Intron coverage metrics
  Novel exon	SPAC1296.03c	De novo transcript assembly

What computational approaches can predict the structure and domains of SPAC12B10.02c?

With limited experimental structural data available for SPAC12B10.02c, computational approaches become essential:

• Ab initio and Template-Based Modeling:

  • AlphaFold2 can generate high-confidence structural predictions

  • HHpred searches for remote homologs as modeling templates

  • I-TASSER integrates multiple threading approaches

• Domain and Motif Analysis:

  • Scan for conserved domains using InterProScan

  • Predict transmembrane regions using TMHMM or Phobius

  • Identify potential post-translational modification sites

• Molecular Dynamics Simulations:

  • Validate structural stability in membrane environments

  • Identify potential ligand binding sites

  • Simulate conformational changes under different conditions

• Structure-Function Predictions:

  • Use predicted structure to design targeted mutations

  • Identify surface-exposed residues for interaction studies

  • Generate hypotheses about functional mechanisms

How should researchers approach post-translational modification analysis of SPAC12B10.02c?

Post-translational modifications can significantly impact protein function. For SPAC12B10.02c:

• Mass Spectrometry-Based PTM Mapping:

  • Use enrichment techniques for specific modifications (phosphorylation, ubiquitination)

  • Apply multiple proteases to achieve high sequence coverage

  • Implement data-dependent and data-independent acquisition methods

• Site-Directed Mutagenesis Validation:

  • Create alanine substitutions at predicted modification sites

  • Generate phosphomimetic mutations (S/T to D/E) to simulate constitutive phosphorylation

  • Test the functional consequences of these mutations

• Dynamic PTM Profiling:

  • Monitor modifications across cell cycle stages

  • Compare modifications during vegetative growth versus sexual reproduction

  • Identify enzymes responsible for adding or removing modifications

• Integration with S. pombe PTM Databases:

  • Cross-reference findings with existing phosphoproteomic datasets

  • Compare with known PTM patterns of related proteins

  • Develop a temporal map of modification events

What phenotypic assays are most informative for characterizing SPAC12B10.02c mutants?

A comprehensive phenotypic analysis should include:

• Growth and Viability Assays:

  • Test growth rates in various media compositions

  • Perform spot assays under stress conditions (temperature, oxidative stress, cell wall stress)

  • Analyze cell cycle progression using flow cytometry

• Morphology and Cytoskeletal Organization:

  • Examine cell shape and size by microscopy

  • Stain for actin, microtubules, and septum formation

  • Quantify abnormal morphological features

• Mating and Sporulation Efficiency:

  • Measure mating frequency and zygote formation

  • Assess spore viability and germination rates

  • Analyze meiotic progression using stage-specific markers

• Molecular Phenotyping:

  • Conduct transcriptome analysis under normal and stress conditions

  • Perform metabolomic profiling to identify metabolic alterations

  • Use proteomics to detect changes in protein abundance and modifications

How can researchers effectively design and implement gene replacement strategies for SPAC12B10.02c?

For successful genetic manipulation of SPAC12B10.02c:

• Gene Replacement Strategies:

  • Use homologous recombination with 50-100bp flanking sequences

  • Consider CRISPR-Cas9 approaches for increased efficiency

  • Implement a two-step strategy for unmarked deletions

• Verification Methods:

  • Design PCR primers outside the manipulated region

  • Sequence across junctions to confirm precise integration

  • Verify expression levels of manipulated genes by RT-qPCR

• Construction of Tagged Variants:

  • Position tags to minimize functional interference

  • Use linker sequences between the protein and tag

  • Generate N- and C-terminal tags to determine optimal configuration

• Recommended Controls:

  • Include wild-type strains processed in parallel

  • Generate marker-only integrations as controls

  • Create point mutants as functional controls

An example gene replacement strategy based on successful approaches in S. pombe:

How does SPAC12B10.02c compare to similar proteins in other yeast species?

Understanding the evolutionary context of SPAC12B10.02c requires:

• Ortholog Identification:

  • Perform reciprocal BLAST searches against fungal genomes

  • Use OrthoMCL or OrthoFinder for ortholog clustering

  • Construct gene trees to resolve orthology relationships

• Functional Conservation Analysis:

  • Compare phenotypes of ortholog deletions across species

  • Assess complementation by heterologous expression

  • Examine conservation of protein interaction networks

• Structural Conservation:

  • Align protein sequences to identify conserved domains and motifs

  • Map conservation onto predicted structural models

  • Identify regions under selection pressure

• Evolutionary Rate Analysis:

  • Calculate dN/dS ratios to detect selective pressure

  • Compare rates of evolution with functionally related genes

  • Identify lineage-specific adaptations

What can genomic context tell us about the potential function of SPAC12B10.02c?

Genomic context can provide valuable functional insights:

• Chromosomal Location Analysis:

  • Examine neighboring genes for functional relationships

  • Identify conserved gene clusters across species

  • Analyze shared regulatory elements

• Co-expression Network Analysis:

  • Build co-expression networks from transcriptomic data

  • Identify genes with similar expression patterns across conditions

  • Infer potential functions from characterized co-expressed genes

• Synteny Analysis:

  • Compare gene order conservation across yeast species

  • Identify genomic rearrangements that might affect function

  • Look for patterns of co-evolution with nearby genes

• Regulatory Element Identification:

  • Map transcription factor binding sites in the promoter region

  • Identify conserved non-coding sequences

  • Analyze chromatin state at the SPAC12B10.02c locus

What are effective approaches for studying membrane localization and topology of SPAC12B10.02c?

As SPAC12B10.02c likely contains transmembrane domains, specialized approaches are needed:

• Fluorescent Protein Tagging:

  • Use split fluorescent proteins to determine topology

  • Create multiple constructs with tags at different positions

  • Perform time-lapse imaging to track dynamic localization

• Biochemical Topology Mapping:

  • Implement proteinase K protection assays

  • Use glycosylation mapping with engineered sites

  • Perform limited proteolysis followed by mass spectrometry

• Super-Resolution Microscopy:

  • Apply PALM or STORM for nanoscale localization

  • Use correlative light and electron microscopy (CLEM)

  • Implement live-cell TIRF microscopy for surface dynamics

• Membrane Fractionation:

  • Separate different cellular compartments by density gradient centrifugation

  • Use detergent resistance to assess lipid raft association

  • Analyze co-fractionation with known membrane markers

How can researchers effectively study the role of SPAC12B10.02c during meiosis and sexual reproduction?

Given its potential role in sexual reproduction , specialized approaches are required:

• Synchronization Methods:

  • Use nitrogen starvation to induce synchronous meiosis

  • Implement temperature-sensitive cell cycle mutants for specific arrest points

  • Apply chemical synchronization with reversible inhibitors

• Stage-Specific Analysis:

  • Monitor protein levels and localization at defined meiotic timepoints

  • Analyze protein-protein interactions at different meiotic stages

  • Perform transcriptome analysis throughout meiotic progression

• Meiotic Phenotyping:

  • Examine homologous recombination efficiency

  • Analyze chromosome segregation patterns

  • Quantify spore viability and germination rates

• Genetic Interaction Mapping During Meiosis:

  • Perform epistasis analysis with known meiotic genes

  • Create double mutants with genes in related processes

  • Use pooled fitness assays to identify genetic interactions specific to meiosis

What databases and bioinformatic resources are most valuable for studying SPAC12B10.02c?

Researchers should utilize these specialized resources:

• S. pombe Specific Resources:

  • PomBase (https://www.pombase.org) - comprehensive database for fission yeast

  • PombeNet - specialized interaction network resource

  • FYPO (Fission Yeast Phenotype Ontology) for standardized phenotype annotation

• General Protein Databases with S. pombe Data:

  • UniProt (http://www.uniprot.org) for curated protein information

  • InterPro for domain and family classification

  • PDB for related protein structures

• Functional Genomics Resources:

  • GEO datasets for expression data across conditions

  • PacBio sequences for alternative splicing information

  • BioGRID for protein-protein interactions

• Analysis Tools and Pipelines:

  • FissionNet for specialized network analysis

  • YEAS-TOOLS for yeast-specific evolutionary analysis

  • DIOPT for ortholog identification

What reagents and strains are available for studying SPAC12B10.02c?

Researchers have access to:

• Commercial Resources:

  • Recombinant SPAC12B10.02c protein for biochemical studies

  • Antibodies against SPAC12B10.02c for Western blotting and immunolocalization

  • Deletion mutant collections containing SPAC12B10.02c mutants

• Community Resources:

  • Tagged strain collections available from stock centers

  • Bioneer deletion library containing heterozygous SPAC12B10.02c deletions

  • Gateway-compatible ORF collections for expression studies

• Specialized Tools:

  • CRISPR-Cas9 systems optimized for S. pombe

  • Inducible expression systems like nmt1-based vectors

  • Specialized vectors for N- and C-terminal tagging

• Strain Development Recommendations:

  • Generate conditional alleles when studying essential functions

  • Create epitope-tagged versions preserving protein function

  • Develop fluorescent protein fusions for localization studies