SPAC7D4.14c Antibody

What is SPAC7D4.14c and why is it significant for research?

SPAC7D4.14c (Iss10/Pir1) is a serine/proline-rich protein with no apparent domains or homologs that functions as a component of the Mtl1-Red1 Core (MTREC) complex in Schizosaccharomyces pombe. This protein is significant because it regulates Mmi1-mediated selective elimination of meiotic mRNAs and is involved in nuclear RNA processing for heterochromatin assembly . Research has shown that Iss10 interacts with Red1 to form a core module that coordinates RNA degradation and localizes to non-coding RNA loci that regulate gene expression in response to environmental changes . Its involvement in heterochromatin islands formation makes it an important target for epigenetic research.

What are the technical specifications of commercially available SPAC7D4.14c antibodies?

Commercial SPAC7D4.14c antibodies are typically provided with the following specifications:

These antibodies are designed specifically for recognizing SPAC7D4.14c protein from S. pombe and are formulated for stability during shipping and storage .

How should SPAC7D4.14c antibodies be stored to maintain activity?

To maintain optimal activity of SPAC7D4.14c antibodies, follow these evidence-based storage protocols:

• Store at -20°C for regular use

• For prolonged storage, maintain at -80°C

• Avoid repeated freeze/thaw cycles (limit to <5 cycles)

• If necessary, prepare working aliquots upon first thaw

• When handling, keep on ice and return to storage promptly

These storage recommendations are based on general antibody preservation principles similar to those for other specialized antibodies .

What are the validated applications for SPAC7D4.14c antibodies in research?

SPAC7D4.14c antibodies have been validated for the following experimental applications:

• Western blot analysis: For detecting SPAC7D4.14c/Iss10 protein expression levels and modifications

• Immunoprecipitation (IP): For protein-protein interaction studies involving MTREC complex components

• Chromatin immunoprecipitation (ChIP): For studying association with heterochromatin islands

• Immunofluorescence (IF): For subcellular localization studies

These applications have been validated in studies examining the role of Iss10/Pir1 in RNA processing and heterochromatin formation .

How can SPAC7D4.14c antibodies be used to study its interaction with the MTREC complex?

To study SPAC7D4.14c interactions with the MTREC complex:

• Co-immunoprecipitation protocol:

  • Prepare cell lysates under non-denaturing conditions

  • Use anti-SPAC7D4.14c antibody coupled to protein A/G beads

  • Incubate overnight at 4°C with gentle rotation

  • Wash with IP buffer containing low detergent

  • Elute and analyze by western blot using antibodies against known MTREC components (Red1, Mtl1, Rmn1)

• Reciprocal co-IP validation:

  • Use antibodies against Red1 or Mtl1 for immunoprecipitation

  • Probe for SPAC7D4.14c in the immunoprecipitates

This approach has successfully demonstrated that SPAC7D4.14c/Pir1 is a core component of MTREC that interacts directly with Red1 .

How do SPAC7D4.14c antibodies help elucidate the role of Iss10/Pir1 in heterochromatin formation?

SPAC7D4.14c antibodies are instrumental in understanding heterochromatin formation through the following methodological approaches:

• ChIP-seq analysis:

  • Crosslink S. pombe cells with formaldehyde

  • Sonicate chromatin to 200-500bp fragments

  • Immunoprecipitate with SPAC7D4.14c antibody

  • Process for next-generation sequencing

  • Analyze enrichment at heterochromatin islands

Research has shown that loss of Pir1 leads to defects in H3K9me at Red1-dependent heterochromatin islands, and low-level Pir1 enrichment can be detected at these islands using ChIP . This confirms its direct involvement in heterochromatin formation.

• Correlation with H3K9me levels:

  • In wildtype vs. Pir1-depleted cells, H3K9me marks can be measured

  • SPAC7D4.14c antibodies help validate knockdown efficiency

These approaches have demonstrated that MTREC protein assemblies containing Pir1 specifically affect formation of heterochromatin islands .

What is the molecular mechanism of SPAC7D4.14c in RNA processing pathways?

The molecular mechanism of SPAC7D4.14c/Iss10 in RNA processing can be studied using antibodies through these advanced methodological approaches:

• RNA immunoprecipitation (RIP):

  • Crosslink RNA-protein complexes in vivo

  • Lyse cells and fragment RNA

  • Immunoprecipitate with SPAC7D4.14c antibody

  • Extract and analyze bound RNA by RT-PCR or sequencing

Research has established that Iss10 regulates Mmi1-mediated selective elimination of meiotic mRNAs . This technique helps identify the specific RNA targets of SPAC7D4.14c.

• Protein complex analysis:

  • Use SPAC7D4.14c antibodies in two-hybrid assays or mass spectrometry

  • Map interaction domains between Iss10 and other components

Studies have revealed that the iss10 gene (SPAC7D4.14c) encodes a protein homologous to budding yeast Thp3, which is involved in transcription elongation .

How can protein-protein interactions of SPAC7D4.14c be evaluated beyond standard co-IP?

Advanced techniques to evaluate SPAC7D4.14c protein interactions include:

• Proximity Ligation Assay (PLA):

  • Fix cells and permeabilize

  • Incubate with SPAC7D4.14c antibody and antibody against potential interactor

  • Add secondary antibodies with conjugated oligonucleotides

  • Ligate and amplify DNA when proteins are in close proximity

  • Visualize interaction signals by fluorescence microscopy

• FRET (Förster Resonance Energy Transfer):

  • Label SPAC7D4.14c and interactor proteins with fluorophore pairs

  • Measure energy transfer between fluorophores when proteins interact

  • Calculate interaction efficiency based on donor-acceptor distances

• Two-hybrid validation:

  • Clone SPAC7D4.14c ORF in vectors like pGAD424

  • Clone interactor (e.g., Red1) in vectors like pGBKT7

  • Transform yeast strain AH109 with both plasmids

  • Assess interaction through reporter gene activation

This approach has been successfully used to demonstrate interaction between Iss10 and Red1 proteins .

What are common technical challenges when using SPAC7D4.14c antibodies in Western blotting?

Common challenges with SPAC7D4.14c antibodies in Western blotting and their methodological solutions include:

• Low signal intensity:

  • Increase antibody concentration (1:500 to 1:200)

  • Extend primary antibody incubation to overnight at 4°C

  • Use enhanced chemiluminescence (ECL) substrates with higher sensitivity

  • Optimize protein extraction with specialized yeast lysis buffers containing protease inhibitors

• High background:

  • Increase blocking time (2 hours at room temperature)

  • Use 5% BSA instead of milk for blocking

  • Increase wash duration and number (5 washes, 10 minutes each)

  • Dilute antibody in fresh blocking buffer

• Protein degradation:

  • Add protease inhibitor cocktail to lysis buffer

  • Keep samples at 4°C throughout processing

  • Add phosphatase inhibitors if studying phosphorylated forms

These optimizations are based on standard Western blot protocols adapted for yeast proteins .

How can specificity of SPAC7D4.14c antibody be validated in experimental settings?

To validate SPAC7D4.14c antibody specificity:

• Genetic knockout controls:

  • Compare signal in wild-type vs. SPAC7D4.14c deletion strains

  • Signal should be absent in knockout strain Western blots

• Epitope competition assay:

  • Pre-incubate antibody with excess purified antigen

  • Compare signal with and without competition

  • Specific signal should be reduced with competition

• Multiple antibody validation:

  • Use antibodies raised against different epitopes of SPAC7D4.14c

  • Compare detection patterns

• Mass spectrometry confirmation:

  • Immunoprecipitate with SPAC7D4.14c antibody

  • Analyze by LC-MS/MS to confirm target protein identity

These validation methods ensure antibody specificity and experimental reliability.

How can SPAC7D4.14c antibodies be used in combination with other techniques to study heterochromatin assembly?

Integrative approaches combining SPAC7D4.14c antibodies with other techniques include:

• ChIP-seq with RNA-seq:

  • Perform ChIP-seq with SPAC7D4.14c antibody

  • In parallel, conduct RNA-seq on the same samples

  • Correlate SPAC7D4.14c binding sites with transcript levels

  • Identify genes whose expression is affected by SPAC7D4.14c localization

• ChIP-qPCR with siRNA knockdown:

  • Deplete SPAC7D4.14c using RNAi

  • Perform ChIP-qPCR for H3K9me at heterochromatin islands

  • Quantify changes in heterochromatin marks

Research has shown that loss of Pir1 affects silencing of target loci, confirming its role in heterochromatin maintenance .

• Mass spectrometry with sequential affinity purification:

  • Use SPAC7D4.14c antibody for first immunoprecipitation

  • Perform second immunoprecipitation with anti-Red1 antibody

  • Identify proteins present in both purifications

  • Characterize core components of the MTREC complex

This approach has identified key MTREC components including Mtl1, Red1, and Pir1/Iss10 .

How can SPAC7D4.14c antibodies contribute to understanding cryptic intron processing?

SPAC7D4.14c antibodies can be utilized to investigate cryptic intron processing through:

• RNA-ChIP followed by sequencing:

  • Immunoprecipitate SPAC7D4.14c-bound RNAs

  • Perform deep sequencing to identify bound transcripts

  • Analyze for presence of cryptic introns

Research has shown that cryptic introns, which are differentially spliced in the absence of certain factors, serve to recruit RNAi and target H3K9me . SPAC7D4.14c may be involved in this process through the MTREC complex.

• Splicing assays with immunodepletion:

  • Prepare nuclear extracts from S. pombe

  • Immunodeplete SPAC7D4.14c using specific antibodies

  • Compare splicing efficiency of transcripts containing cryptic introns

This approach can help determine SPAC7D4.14c's direct role in processing transcripts containing cryptic introns that are important for RNAi-mediated heterochromatin formation.

What alternative epitope targets should be considered when designing new SPAC7D4.14c antibodies?

When designing next-generation SPAC7D4.14c antibodies, researchers should consider:

• Functional domain targeting:

  • Serine/proline-rich regions that may be involved in protein-protein interactions

  • Conserved motifs shared with homologs in other organisms

  • Regions involved in Red1 interaction

• Post-translational modification sites:

  • Potential phosphorylation sites within serine-rich regions

  • Ubiquitination sites that may regulate protein stability

  • Other modifications that might affect function

• Structural considerations:

  • Surface-exposed epitopes for better accessibility

  • Regions less likely to be affected by protein conformational changes

  • Epitopes away from interaction interfaces to avoid interference

These design considerations can improve antibody functionality for specific research applications involving SPAC7D4.14c.