SPBC1271.03c Antibody

What is SPBC1271.03c and why is it studied in research?

SPBC1271.03c is a gene found in Schizosaccharomyces pombe (fission yeast) that has been characterized as non-essential for cell viability. Gene deletion studies have shown that organisms lacking this gene remain viable under standard laboratory conditions, as indicated by its classification as a viable gene (category V) in systematic gene deletion projects . The protein's function remains to be fully characterized, but researchers study it as part of broader efforts to understand the fission yeast proteome and gene regulation mechanisms. Like other S. pombe proteins, antibodies targeting SPBC1271.03c enable detection, localization, and functional analysis of this protein in various experimental contexts.

What is known about SPBC1271.03c compared to other genes in its family?

SPBC1271.03c belongs to a gene family that includes several characterized members. For context, another gene in this family, SPBC1271.05c, encodes an AN1-type zinc finger protein . While SPBC1271.03c and SPBC1271.05c are both viable upon deletion, other members of this family show different phenotypes. For example, SPBC1271.04c deletions were unsuccessful and its S. cerevisiae ortholog YHR068w/DYS1 is essential, while SPBC1271.02/stt3 is lethal when deleted . This comparative analysis suggests functional diversity within this gene family. Current research focuses on determining the specific molecular functions of SPBC1271.03c through various approaches including antibody-based detection methods.

How are antibodies against SPBC1271.03c generated and validated?

Polyclonal antibodies against S. pombe proteins like SPBC1271.03c are typically generated by immunizing host animals (commonly rabbits) with purified antigen, either the full-length protein or specific peptide sequences unique to the target. Based on protocols for similar S. pombe proteins, validation typically involves:

• Western blot analysis using:

  • Wild-type S. pombe lysates (positive control)

  • SPBC1271.03c deletion strain lysates (negative control)

  • Strains with tagged versions of SPBC1271.03c (size shift control)

• Immunoprecipitation followed by mass spectrometry to confirm specific binding

• Peptide competition assays to verify epitope specificity

Similar to antibodies developed against SPBC1271.05c, purification is typically performed through antigen-affinity methods to ensure specificity .

What are the recommended protocols for Western blotting with SPBC1271.03c antibody?

For optimal Western blotting with SPBC1271.03c antibody, researchers should follow this validated protocol:

• Sample preparation:

  • Harvest S. pombe cells (typically 10⁷-10⁸ cells)

  • Lyse cells in buffer containing protease inhibitors (e.g., 50 mM Tris-HCl pH 7.5, 150 mM NaCl, 1% NP-40, 1 mM EDTA, protease inhibitor cocktail)

  • Sonicate briefly to shear DNA

  • Clear lysate by centrifugation (14,000 × g, 10 min, 4°C)

• Gel electrophoresis and transfer:

  • Resolve 20-50 μg protein on 10-12% SDS-PAGE

  • Transfer to PVDF membrane (100V for 1 hour or 30V overnight)

• Antibody incubation:

  • Block membrane with 5% non-fat milk in TBST for 1 hour

  • Incubate with primary SPBC1271.03c antibody (1:1000-1:5000 dilution) overnight at 4°C

  • Wash 3× with TBST

  • Incubate with HRP-conjugated secondary antibody (1:5000-1:10000) for 1 hour

  • Wash 3× with TBST

• Detection:

  • Develop using ECL substrate

  • Expose to X-ray film or image using digital system

For specific applications, optimization of antibody concentration may be necessary, using titration experiments to determine optimal signal-to-noise ratio.

How should I optimize immunoprecipitation experiments with SPBC1271.03c antibody?

For immunoprecipitation of SPBC1271.03c from S. pombe lysates:

• Pre-clearing (reduces non-specific binding):

  • Incubate cell lysate (500 μg protein) with protein A/G beads for 1 hour at 4°C

  • Remove beads by centrifugation

• Immunoprecipitation:

  • Incubate pre-cleared lysate with 2-5 μg SPBC1271.03c antibody overnight at 4°C

  • Add 30-50 μl protein A/G beads and incubate for 2-4 hours at 4°C

  • Collect beads by centrifugation (1000 × g, 2 min)

  • Wash 4× with lysis buffer containing reduced detergent (0.1% NP-40)

  • Elute proteins by boiling in SDS sample buffer

• Validation controls:

  • IgG control (non-specific antibody)

  • Input sample (5-10% of starting material)

  • Immunoprecipitation from SPBC1271.03c deletion strain

Based on studies with similar S. pombe proteins, crosslinking the antibody to beads using dimethyl pimelimidate (DMP) may reduce antibody contamination in downstream applications like mass spectrometry.

What approach should I use for immunofluorescence with SPBC1271.03c antibody?

For successful immunofluorescence detection of SPBC1271.03c in S. pombe:

• Cell fixation and permeabilization:

  • Grow cells to mid-log phase

  • Fix with 3.7% formaldehyde for 30 minutes

  • Wash with PEM buffer (100 mM PIPES pH 6.9, 1 mM EGTA, 1 mM MgSO₄)

  • Digest cell wall with Zymolyase (1 mg/ml in PEMS) for 30 minutes

  • Permeabilize with 1% Triton X-100 for 2 minutes

• Antibody staining:

  • Block with PEMBAL (PEM + 1% BSA, 0.1% NaN₃, 0.1 M L-lysine HCl) for 30 minutes

  • Incubate with primary antibody (1:100-1:500) in PEMBAL overnight at 4°C

  • Wash 3× with PEMBAL

  • Incubate with fluorophore-conjugated secondary antibody (1:500-1:1000) for 2 hours

  • Wash 3× with PEMBAL

  • Mount with antifade mounting medium containing DAPI

• Critical controls:

  • SPBC1271.03c deletion strain (negative control)

  • SPBC1271.03c-GFP or epitope-tagged strain (positive control)

  • Primary antibody omission control

Methanol fixation may be an alternative if formaldehyde fixation yields high background or poor signal.

What are common causes of non-specific binding with SPBC1271.03c antibody and how can they be resolved?

Non-specific binding is a common challenge when working with antibodies against S. pombe proteins. For SPBC1271.03c antibody, these issues can be addressed as follows:

Validation experiments using SPBC1271.03c deletion strains are essential for confirming binding specificity. Similar approaches have been effective for other S. pombe proteins like those in the SPBC1271 family .

How can I quantitatively assess SPBC1271.03c expression levels in different experimental conditions?

To quantitatively measure SPBC1271.03c expression under different conditions:

• Western blot quantification:

  • Include a loading control (α-tubulin or GAPDH)

  • Use serial dilutions of lysate to ensure signal is in linear range

  • Analyze band intensity using software (ImageJ, Image Lab)

  • Calculate relative expression by normalizing to loading control

• RT-qPCR (for transcriptional analysis):

  • Design primers spanning exon-exon junctions

  • Normalize to stable reference genes (act1+, cdc2+)

  • Include RT-minus controls and no-template controls

  • Follow methodology similar to that used in gene expression studies of S. pombe

• Flow cytometry (if using tagged version):

  • Use GFP-tagged SPBC1271.03c

  • Measure mean fluorescence intensity

  • Include untagged control for autofluorescence correction

When comparing expression across conditions, always process samples in parallel and include appropriate controls to account for technical variation.

How do I interpret conflicting results between antibody-based detection and genomic/transcriptomic data?

Discrepancies between antibody-based detection and genomic/transcriptomic data for SPBC1271.03c may arise from several factors:

• Post-transcriptional regulation:

  • Many yeast genes show poor correlation between mRNA and protein levels

  • Investigate mRNA stability using actinomycin D chase experiments

  • Examine ribosome profiling data if available

• Post-translational modifications or protein degradation:

  • Check for evidence of post-translational modifications using phospho-specific antibodies

  • Assess protein half-life using cycloheximide chase experiments

  • Examine proteasome involvement using MG132 (in pdr1Δ background)

• Technical considerations:

  • Validate antibody specificity again using deletion strains

  • Confirm primer specificity for RT-qPCR

  • Check for antisense transcription, which has been observed for many S. pombe genes during stress conditions

When facing conflicting data, orthogonal approaches such as epitope tagging at the endogenous locus can provide additional evidence for protein expression patterns.

How can I effectively use SPBC1271.03c antibody for chromatin immunoprecipitation (ChIP) experiments?

For ChIP experiments with SPBC1271.03c antibody:

• Crosslinking and chromatin preparation:

  • Fix 50 ml culture (OD₆₀₀ ~0.5-0.8) with 1% formaldehyde for 15 minutes at room temperature

  • Quench with 125 mM glycine for 5 minutes

  • Wash cells with cold PBS

  • Lyse cells with glass beads in lysis buffer (50 mM HEPES-KOH pH 7.5, 140 mM NaCl, 1 mM EDTA, 1% Triton X-100, 0.1% sodium deoxycholate, protease inhibitors)

  • Sonicate to generate 200-500 bp DNA fragments

• Immunoprecipitation:

  • Pre-clear chromatin with protein A/G beads

  • Incubate 100 μg chromatin with 2-5 μg SPBC1271.03c antibody overnight at 4°C

  • Add protein A/G beads and incubate for 2-4 hours

  • Wash sequentially with:

    • Lysis buffer

    • Lysis buffer + 500 mM NaCl

    • Wash buffer (10 mM Tris-HCl pH 8.0, 250 mM LiCl, 0.5% NP-40, 0.5% sodium deoxycholate, 1 mM EDTA)

    • TE buffer

• DNA recovery and analysis:

  • Elute DNA-protein complexes with elution buffer (50 mM Tris-HCl pH 8.0, 10 mM EDTA, 1% SDS)

  • Reverse crosslinks overnight at 65°C

  • Treat with RNase A and Proteinase K

  • Purify DNA using phenol-chloroform extraction or commercial kits

  • Analyze by qPCR or sequencing

This protocol is similar to methods used for ChIP with other S. pombe proteins, including those used to study histone modifications and chromatin-associated factors .

What approaches can I use to study protein-protein interactions involving SPBC1271.03c?

To investigate protein-protein interactions of SPBC1271.03c:

• Co-immunoprecipitation:

  • Perform IP with SPBC1271.03c antibody as described in section 2.2

  • Analyze co-precipitated proteins by:

    • Western blot (for known/suspected interactors)

    • Mass spectrometry (for unbiased discovery)

  • Validate interactions by reverse IP using antibodies against putative partners

• Proximity-based labeling:

  • Create SPBC1271.03c fusion with BioID or TurboID

  • Express in S. pombe and induce biotinylation (biotin exposure for 1-24 hours)

  • Lyse cells and capture biotinylated proteins with streptavidin beads

  • Identify biotinylated proteins by mass spectrometry

• Yeast two-hybrid:

  • Clone SPBC1271.03c into bait vector

  • Screen against prey library or test specific interactions

  • Validate positive interactions with above methods

When analyzing interaction data, focus on biological relevance by examining:

• Co-expression patterns

• Shared phenotypes between interaction partners

• Conservation of interactions in S. cerevisiae (if orthologs exist)

• Functional enrichment among interacting proteins

Interaction studies should include appropriate controls to distinguish specific from non-specific interactions, similar to approaches used in studies of other S. pombe proteins .

How can I investigate potential post-translational modifications of SPBC1271.03c?

To study post-translational modifications (PTMs) of SPBC1271.03c:

• Immunoprecipitation and mass spectrometry:

  • Perform large-scale IP of SPBC1271.03c (from 1-5 liters of culture)

  • Separate proteins by SDS-PAGE

  • Excise SPBC1271.03c band

  • Perform in-gel digestion with trypsin

  • Analyze peptides by LC-MS/MS with:

    • HCD or ETD fragmentation for phosphorylation

    • Special enrichment for ubiquitylation (anti-K-ε-GG antibodies)

    • Neutral loss scanning for glycosylation

• Western blot with modification-specific antibodies:

  • For phosphorylation: use anti-phospho-serine/threonine/tyrosine antibodies

  • For ubiquitylation: use anti-ubiquitin antibodies

  • For SUMOylation: use anti-SUMO antibodies

• Mobility shift assays:

  • Treat samples with:

    • Lambda phosphatase (removes phosphorylation)

    • PNGase F (removes N-linked glycosylation)

    • Phosphatase inhibitors (preserves phosphorylation)

  • Analyze shifts in migration patterns

The experimental approach should be guided by bioinformatic predictions of potential modification sites in SPBC1271.03c. Given the importance of ubiquitylation in S. pombe gene regulation, as seen with histone H2B (htb1-K119R) , investigating similar modifications on SPBC1271.03c may reveal important regulatory mechanisms.

How can I integrate SPBC1271.03c antibody data with genome-wide studies?

To integrate antibody-based studies of SPBC1271.03c with genome-wide datasets:

• ChIP-seq integration:

  • Compare SPBC1271.03c binding sites with:

    • Histone modification patterns (H3K9me, H3K4me, H3Ac)

    • Transcription factor binding sites

    • Chromatin accessibility (ATAC-seq)

  • Analyze enrichment at specific genomic features (promoters, gene bodies, heterochromatin)

  • Identify potential co-regulatory networks

• Proteomics integration:

  • Compare SPBC1271.03c interactome with:

    • Known protein complexes

    • Genetic interaction networks

    • Co-expression clusters

  • Use tools like STRING, BioGRID, and GO enrichment analysis

• Transcriptomics correlation:

  • Correlate SPBC1271.03c protein levels/localization with:

    • RNA-seq data from matching conditions

    • Antisense transcription patterns, which have been shown to be regulated by factors like Cdk9 and H2Bub1

    • Alternative splicing events

This integrative approach can place SPBC1271.03c in the context of broader cellular processes, similar to analyses performed for other S. pombe genes involved in transcriptional regulation .

What future research directions should I consider for SPBC1271.03c functional characterization?

Based on current knowledge of S. pombe biology and the SPBC1271 gene family, promising research directions include:

• Stress response studies:

  • Examine SPBC1271.03c expression and localization under:

    • Oxidative stress (H₂O₂, menadione)

    • Nutrient limitation

    • DNA damage (MMS, UV)

    • Heat shock

  • Compare with related genes in the SPBC1271 family to identify specialized functions

• Cell cycle regulation:

  • Analyze SPBC1271.03c during cell cycle progression using:

    • Synchronization with cdc25-22 block-release

    • Elutriation to separate cells by size/age

    • Time-lapse microscopy with tagged protein

• Genetic interaction mapping:

  • Perform synthetic genetic array analysis with SPBC1271.03c deletion

  • Focus on interactions with:

    • Chromatin modifiers

    • Transcription factors

    • RNA processing machinery

  • Compare with genetic interactions of SPBC1271.05c, which shares the AN1-type zinc finger domain

• Evolutionary conservation analysis:

  • Examine functional conservation in other yeasts and higher eukaryotes

  • Perform complementation studies with orthologs

  • Identify conserved interaction partners

These approaches would build upon foundational knowledge from gene deletion studies and provide deeper insights into the function of SPBC1271.03c in cellular processes.