SPBC1683.13c Antibody

What is SPBC1683.13c and why is it significant for research?

SPBC1683.13c (also known as cha4) is a gene in Schizosaccharomyces pombe (fission yeast) that encodes a predicted transcription factor. According to BioGRID database information, it's classified as a transcription factor with specific GO (Gene Ontology) annotations related to molecular function and biological processes . The significance of this gene lies in its potential regulatory role in transcriptional networks in S. pombe, which serves as an important model organism for studying eukaryotic cell biology. Research involving SPBC1683.13c can provide insights into transcriptional regulation mechanisms that may be conserved across eukaryotes.

What are the technical specifications of the SPBC1683.13c antibody?

Based on the available catalog information, the SPBC1683.13c antibody (product code CSB-PA868421XA01SXV) is specific to Schizosaccharomyces pombe (strain 972 / ATCC 24843) and corresponds to UniProt ID Q9P6I9 . The antibody is available in different size options (0.1ml/1ml) and is designed for research applications. Researchers should verify the specific applications (Western blot, immunoprecipitation, ChIP, etc.) for which the antibody has been validated before use in experimental protocols.

How can the SPBC1683.13c antibody be used in chromatin immunoprecipitation (ChIP) experiments?

For ChIP experiments with SPBC1683.13c antibody, follow these methodological steps:

• Cross-link S. pombe cells using 1% formaldehyde for 10-15 minutes at room temperature

• Harvest cells and prepare chromatin as described in established protocols

• Sonicate chromatin to fragments of ~200-500bp

• Immunoprecipitate with SPBC1683.13c antibody using a protocol similar to that described for other S. pombe transcription factors:

  • Incubate chromatin with 2-5 μg of SPBC1683.13c antibody overnight at 4°C

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

  • Wash with increasingly stringent buffers

  • Reverse crosslinks and purify DNA

• Analyze by qPCR or sequence the recovered DNA

For genome-wide binding profiles, ChIP-chip or ChIP-seq methodologies can be employed similar to those described for other S. pombe transcription factors like Atf1/Pcr1 .

What are the best approaches for using SPBC1683.13c antibody in western blotting of S. pombe proteins?

For optimal western blotting with SPBC1683.13c antibody:

• Prepare total cell lysates following the protocol described for Rhb1 protein detection in S. pombe:

  • Lyse cells with glass beads in lysis buffer (150 mM NaCl and 10 mM Tris–HCl, pH 7.0) containing 0.5% Triton X-100 and 0.5% deoxycholate

  • Add protease inhibitors (0.4 mM phenylmethylsulfonyl fluoride and 1× protease inhibitor cocktail)

  • Load equal amounts of protein onto a 15% polyacrylamide gel

  • Transfer to nitrocellulose membrane

• For blotting:

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

  • Incubate with SPBC1683.13c antibody (1:1000 dilution is recommended as a starting point)

  • Use appropriate secondary antibody such as HRP-conjugated anti-rabbit IgG

  • Develop using ECL system

• For control and normalization, TAT-1 antibody against S. pombe tubulin can be used as described in the literature .

How should researchers validate the specificity of the SPBC1683.13c antibody?

To validate antibody specificity:

• Perform western blotting comparing wild-type and SPBC1683.13c deletion strains (if available)

• For epitope-tagged versions of the protein, compare detection with both anti-tag antibody and SPBC1683.13c antibody

• Conduct immunoprecipitation followed by mass spectrometry to confirm the identity of pulled-down proteins

• Perform competition assays with recombinant SPBC1683.13c protein to demonstrate specific binding

• If conducting ChIP experiments, validate binding sites using known genomic regions and compare with negative control regions

The specificity validation is crucial as we've seen with other S. pombe research where antibody specificity impacts experimental interpretation, such as in Php4 studies .

What are the main challenges in working with transcription factor antibodies in S. pombe?

Key challenges include:

• Expression level variability: Transcription factors often have low abundance and dynamic expression based on cellular conditions (e.g., nutrient availability, stress)

• Cross-reactivity issues: S. pombe contains multiple transcription factors with similar domains, potentially leading to non-specific binding

• Native versus tagged approaches:

  Approach	Advantages	Disadvantages
  Native antibody	Detects endogenous protein, no tagging effects	May have specificity issues
  Tagged protein antibody	High specificity to tag	Tag may interfere with function

• Chromatin accessibility: Transcription factors may be embedded in complex chromatin structures, requiring optimization of extraction and immunoprecipitation conditions

• Environmental conditions: As seen in numerous studies , transcription factor binding and activity in S. pombe is highly dependent on environmental conditions (iron availability, nitrogen source, stress)

How can SPBC1683.13c antibody be used to study transcriptional responses to environmental stress?

The SPBC1683.13c antibody can be employed to investigate stress responses through:

• ChIP-seq time course experiments following exposure to different stressors (oxidative stress, nutrient limitation)

• Comparison of binding profiles under different nutrient conditions, similar to studies of other transcription factors like Php4 , which responds to iron availability

• Integration with transcriptome data to correlate binding with gene expression changes

• Co-immunoprecipitation to identify interacting partners under different stress conditions

For experimental design, researchers can follow the approach used for the Atf1 transcription factor, which was mapped genome-wide before and after H₂O₂ treatment . The binding profile can then be correlated with transcriptional responses to identify direct regulatory targets.

What role might SPBC1683.13c play in nutrient sensing based on current knowledge of S. pombe transcription factors?

Based on extensive research on nutrient sensing in S. pombe:

• SPBC1683.13c may be involved in nutrient-dependent transcriptional regulation, similar to other transcription factors like Loz1 (zinc homeostasis) or Php4 (iron regulation)

• Potential functions could include:

  • Regulation of genes involved in nitrogen utilization, similar to AreA-type GATA factors

  • Mediating responses to TOR signaling pathways, which coordinate growth with nutrient availability

  • Controlling expression of transporters for specific nutrients

• To investigate this function:

  • Compare binding profiles in rich vs. minimal media

  • Analyze phenotypes of SPBC1683.13c deletion in various nutrient conditions

  • Perform transcriptome analysis of deletion strains under different nutrient conditions

• Potential target genes could include transporters, metabolic enzymes, or stress response genes based on patterns observed with other nutrient-responsive transcription factors.

How can SPBC1683.13c antibody be used in conjunction with chromatin organization studies?

For chromatin organization studies:

• Sequential ChIP (ChIP-reChIP) can be performed using SPBC1683.13c antibody followed by antibodies against chromatin modifiers to determine co-occupancy at specific genomic loci

• SPBC1683.13c binding sites can be analyzed relative to chromatin boundaries and heterochromatin domains, similar to studies on IRC boundary elements

• Combined with histone modification ChIPs (H3K9me2, H4K16ac), SPBC1683.13c binding patterns can reveal relationships with specific chromatin states

• The antibody can be used in CUT&RUN or CUT&Tag protocols for high-resolution mapping of binding sites relative to nucleosome positioning

• For researchers interested in chromatin regulation, comparison between wild-type and strains with mutations in chromatin regulators (e.g., clr4Δ) can reveal dependency relationships between SPBC1683.13c and chromatin state.

What approaches can be used to integrate SPBC1683.13c antibody-generated data with global gene expression and fitness profiling?

Integrative approaches include:

• Combined ChIP-seq and RNA-seq analysis to correlate binding sites with transcriptional effects

• Integration with fitness profiling data:

  • Compare SPBC1683.13c binding profiles with the fitness effects of gene deletions in different nutrient environments

  • Identify whether SPBC1683.13c targets are enriched among genes that show fitness defects in specific conditions

• Multi-omic integration framework:

  Data Type	Technique	Integration Approach
  Binding sites	ChIP-seq with SPBC1683.13c antibody	Map binding sites genome-wide
  Expression effects	RNA-seq of cha4Δ vs. wild-type	Identify differentially expressed genes
  Genetic interactions	Synthetic genetic array	Find genetic interactors of SPBC1683.13c
  Fitness effects	QFA in different conditions	Correlate binding with fitness contributions

• For computational analysis, researchers can employ enrichment analysis to determine if SPBC1683.13c targets are overrepresented in specific biological processes or environmental response pathways.

What is known about potential SPBC1683.13c interactions with other transcription factors or regulatory complexes?

While specific interaction data for SPBC1683.13c/Cha4 is limited in the provided search results, researchers can investigate potential interactions through:

• Co-immunoprecipitation with SPBC1683.13c antibody followed by mass spectrometry to identify interacting proteins

• Comparing binding profiles with other transcription factors such as Atf1/Pcr1 to identify co-regulated regions

• Exploring similar patterns to other S. pombe transcription factors like Php4, which functions within the CCAAT-binding complex , or Fep1, which responds to iron availability

• Investigating potential roles in TOR signaling pathways based on the extensive fitness profiling data available for gene deletions under TOR inhibition

• Examining potential roles in stress responses similar to the Sty1-Atf1 pathway

How can researchers determine if SPBC1683.13c has iron-responsive functions similar to other S. pombe transcription factors?

To investigate potential iron-responsive functions:

• Compare binding profiles using ChIP-seq with SPBC1683.13c antibody under iron-replete and iron-deplete conditions

• Analyze expression of known iron-regulated genes (e.g., frp1⁺, fio1⁺, fip1⁺, abc3⁺) in wild-type versus cha4Δ strains

• Determine if SPBC1683.13c binding is influenced by Fep1 or Php4 activity by performing ChIP in fep1Δ or php4Δ backgrounds

• Investigate physical interactions with known iron-responsive factors using co-immunoprecipitation approaches

• Examine localization patterns under varying iron conditions using the antibody for immunofluorescence

Several S. pombe transcription factors are known to respond to iron availability, including Fep1 (repressing genes during iron sufficiency) and Php4 (repressing iron-utilizing genes during iron deficiency) , making this a relevant area of investigation.

What are the optimal fixation and extraction conditions for detecting SPBC1683.13c in different subcellular compartments?

For comprehensive detection across subcellular compartments:

• Nuclear extraction:

  • Fix cells with 1% formaldehyde for 10 minutes

  • Prepare spheroplasts as described in established protocols

  • Isolate nuclei using a sucrose gradient

  • Extract nuclear proteins with high-salt buffer (300-500 mM NaCl)

• Cytoplasmic detection:

  • Use gentle lysis conditions without detergents

  • Separate cytoplasmic fraction by centrifugation

  • Concentrate proteins if necessary before western blotting

• Chromatin-bound fraction:

  • After nuclear isolation, treat with nuclease (DNase I or Benzonase)

  • Extract chromatin-bound proteins with buffer containing 0.5% Triton X-100

• For immunofluorescence:

  • Fix cells with 3% paraformaldehyde

  • Digest cell wall with zymolyase

  • Permeabilize with 0.1% Triton X-100

  • Use SPBC1683.13c antibody at 1:100-1:500 dilution

Optimization is critical as transcription factors may shuttle between compartments depending on cellular conditions.

How should researchers address potential post-translational modifications when using SPBC1683.13c antibody?

Post-translational modifications (PTMs) may affect antibody recognition:

• Phosphorylation analysis:

  • Treat extracts with lambda phosphatase to remove phosphorylation

  • Compare migration patterns before and after treatment

  • Use phospho-specific antibodies if available for key residues

• Other modifications:

  • Consider potential ubiquitination, acetylation, or SUMOylation of SPBC1683.13c

  • Use deubiquitinating enzymes or deacetylases to remove these modifications

  • Perform immunoprecipitation under native conditions followed by mass spectrometry to identify modifications

• For transcription factors, DNA binding can be regulated by PTMs - consider:

  Modification	Potential Effect	Detection Method
  Phosphorylation	Altered DNA binding or localization	Phospho-specific antibodies, Phos-tag gels
  Acetylation	Changed protein stability or interactions	Anti-acetyl-lysine antibodies
  SUMOylation	Repressive function	Anti-SUMO antibodies

• Analyze modifications in response to stress or nutrient conditions, as many transcription factors show condition-dependent modifications.

How does SPBC1683.13c compare to its orthologs in other yeast species?

For comparative analysis:

• S. cerevisiae comparison:

  • Identify potential orthologs through sequence homology

  • Compare functional data with S. cerevisiae transcription factors involved in similar processes

  • Analyze conservation of binding motifs and regulatory domains

• Functional conservation:

  • Examine if SPBC1683.13c can complement deletion of orthologous genes in other yeasts

  • Compare binding profiles and target genes across species

  • Analyze conservation of regulatory mechanisms

• Evolutionary analysis:

  • Perform phylogenetic analysis of SPBC1683.13c across fungal species

  • Identify conserved domains that may indicate preserved function

  • Examine conservation of regulatory regions in target genes

This approach has been valuable for understanding the evolution of nutrient-responsive transcription factors, as seen in studies of iron-responsive transcription factors across different fungal species .

What complementary approaches can be used alongside SPBC1683.13c antibody to fully characterize its function?

To comprehensively characterize SPBC1683.13c function:

• Genetic approaches:

  • Create deletion and conditional mutants of SPBC1683.13c

  • Perform synthetic genetic array analysis to identify genetic interactions

  • Use CRISPR-based approaches for precise mutations in specific domains

• Biochemical characterization:

  • Express and purify recombinant SPBC1683.13c for in vitro DNA binding assays

  • Perform electrophoretic mobility shift assays to determine binding specificity

  • Use protein microarrays to identify interaction partners

• Genomic approaches:

  • Perform ChIP-seq with SPBC1683.13c antibody under various conditions

  • Conduct RNA-seq of wild-type vs. mutant strains

  • Use ATAC-seq to examine chromatin accessibility changes in mutants

• Structural biology:

  • Determine the structure of DNA-binding domains

  • Investigate structural changes upon binding to DNA or protein partners

  • Analyze how potential modifications affect structure

The combination of these approaches with antibody-based detection methods provides a comprehensive understanding of SPBC1683.13c function.