SPCC737.05 Antibody

What is Sup11p and what cellular functions does it regulate?

Sup11p, encoded by the SPCC737.05 gene in S. pombe, is an essential protein required for cell viability that participates specifically in cell wall remodeling during septum assembly. The protein plays a critical role in O-mannosylation pathways, affecting protein glycosylation throughout the cell. When Sup11p is depleted, cells exhibit upregulation of glucanases (including Gas2p) and chitin synthases, demonstrating its regulatory role in cell wall component synthesis. The protein's essential nature makes it particularly important for understanding fundamental cellular processes in fission yeast, with potential implications for antifungal drug development targeting cell wall integrity pathways.

What are the key technical specifications of the SPCC737.05 antibody?

The SPCC737.05 antibody was generated using GST-fusion peptides of Sup11p as the immunogen. Key specifications include:

These specifications help researchers determine compatibility with their experimental systems and protocols.

What validation methods have been applied to confirm SPCC737.05 antibody specificity?

Several validation approaches have been employed to confirm the specificity of the SPCC737.05 antibody. These include proteinase K protection assays, which confirmed membrane localization of Sup11p, and EndoH treatment that revealed N-glycosylation status in mutant strains. Additionally, microarray hybridization experiments demonstrated transcriptional changes in sup11Δ mutants. These validation methods align with the principles outlined in the "five pillars" of antibody characterization proposed by the International Working Group for Antibody Validation, which include genetic strategies (using knockout controls), orthogonal strategies (comparing antibody-dependent and independent results), and multiple antibody strategies . Proper validation is essential since inadequately characterized antibodies can lead to unreliable scientific results and poor reproducibility.

What downstream applications has the SPCC737.05 antibody been validated for?

The SPCC737.05 antibody has been validated for specific applications including Western blot analysis and immunofluorescence (IF) microscopy. In Western blotting, the antibody has been used to detect native Sup11p expression levels and to monitor changes in protein abundance during various experimental conditions. For immunofluorescence applications, the antibody has proven useful for localizing Sup11p within cellular compartments, particularly for studying its distribution during different cell cycle stages and under various stress conditions. While these are the primary validated applications, the antibody may potentially be suitable for other techniques like immunoprecipitation, though explicit validation data for such applications is currently limited.

What controls should be included when using the SPCC737.05 antibody?

When using the SPCC737.05 antibody, several essential controls should be implemented to ensure experimental validity:

• Negative controls: Include samples from Sup11p knockout or knockdown strains when possible. If genetic deletion is lethal, conditional repression systems should be employed .

• Specificity controls: Pre-absorption with the immunizing antigen (GST-Sup11p fusion protein) to demonstrate binding specificity.

• Secondary antibody controls: Samples incubated with secondary antibody only to identify potential non-specific binding.

• Isotype controls: Include appropriate isotype-matched irrelevant antibodies to identify non-specific binding due to the antibody class.

• Loading controls: Use established housekeeping proteins or total protein staining methods to normalize protein loading in Western blots.

These controls are critical for generating reliable and reproducible data when using antibodies in research settings .

How can the SPCC737.05 antibody be used to investigate Sup11p's role in O-mannosylation pathways?

The SPCC737.05 antibody can be strategically employed to investigate Sup11p's role in O-mannosylation through several advanced approaches. Researchers can design co-immunoprecipitation experiments using the antibody to identify direct protein interactions between Sup11p and other O-mannosylation pathway components. Western blotting with the SPCC737.05 antibody can be combined with glycoprotein staining techniques to correlate Sup11p expression levels with global O-mannosylation patterns.

For more sophisticated analyses, researchers can implement temporal studies using temperature-sensitive mutants, applying the antibody to track Sup11p localization and abundance during acute disruption of O-mannosylation. The antibody can also be utilized in proximity ligation assays (PLA) to visualize and quantify interactions between Sup11p and suspected partner proteins in situ. When combined with glycoproteomics approaches, researchers can correlate Sup11p abundance (detected via the antibody) with specific changes in the O-mannosylated proteome to elucidate its substrate specificity and functional significance in the pathway.

What experimental approaches can reveal the relationship between Sup11p and cell wall integrity pathways?

To investigate the relationship between Sup11p and cell wall integrity pathways, researchers can implement several sophisticated experimental approaches utilizing the SPCC737.05 antibody:

• Stress response studies: Apply cell wall stressors (Calcofluor White, Congo Red) while monitoring Sup11p localization and abundance via immunofluorescence and Western blotting with the SPCC737.05 antibody.

• Genetic interaction analyses: Combine Sup11p conditional repression with mutations in cell wall integrity pathway components, using the antibody to quantify compensatory changes in Sup11p expression.

• Pathway activation monitoring: Use the antibody in parallel with phospho-specific antibodies against MAP kinase pathway components to correlate Sup11p levels with cell wall integrity signaling activation.

• Temporal dynamics: Implement time-course experiments during cell division, using the antibody to track Sup11p redistribution relative to cell wall synthesis markers.

• Correlative microscopy: Combine electron microscopy of cell wall ultrastructure with super-resolution immunofluorescence using the SPCC737.05 antibody to precisely map Sup11p localization relative to cell wall defects.

These approaches can provide mechanistic insights into how Sup11p coordinates cell wall remodeling during growth and division.

How can researchers analyze transcriptional changes associated with Sup11p depletion using the antibody?

Researchers can implement sophisticated approaches to analyze transcriptional changes associated with Sup11p depletion while using the SPCC737.05 antibody as a validation tool. First, establish a conditional Sup11p depletion system (e.g., using a tetracycline-repressible promoter) and confirm protein depletion via Western blotting with the SPCC737.05 antibody. This validation ensures that observed transcriptional changes directly correlate with decreased Sup11p levels.

Next, implement RNA-seq or microarray analysis at multiple time points following Sup11p depletion, creating a temporal profile of transcriptional responses. The antibody can be used in parallel ChIP-seq experiments to determine if Sup11p itself has any direct DNA interactions that might influence gene expression. Previous studies have identified several genes affected by Sup11p depletion, including upregulation of gas2+ (β-1,3-glucanosyltransferase) and cwf18+ (chitin synthase activator), along with downregulation of ags2+ (α-glucan synthase) and psu1+ (β-glucanase inhibitor).

For functional validation, the antibody can be used in rescue experiments where wild-type Sup11p is reintroduced to determine which transcriptional changes are reversible, helping distinguish primary from secondary effects. Quantitative immunoblotting with SPCC737.05 can also correlate the degree of Sup11p depletion with the magnitude of transcriptional changes, establishing potential threshold effects in the regulatory network.

What are the methodological considerations for studying Sup11p N-glycosylation using the SPCC737.05 antibody?

When investigating Sup11p N-glycosylation using the SPCC737.05 antibody, researchers should consider several methodological refinements:

• Glycosidase treatments: Prior to immunoblotting with SPCC737.05 antibody, treat samples with EndoH, PNGase F, or O-glycosidase to distinguish between different glycan modifications. Previous research has revealed unusual N-glycosylation at an N-X-A sequon in O-mannosylation-deficient strains.

• Gel system optimization: Utilize gradient gels (4-15%) to better resolve subtle mobility shifts caused by glycosylation changes. Consider using Phos-tag gels if phosphorylation may be occurring simultaneously.

• Sequential immunoprecipitation: First immunoprecipitate with SPCC737.05 antibody, then probe with glycan-specific lectins or antibodies to characterize the type and extent of glycosylation.

• Site-directed mutagenesis: Create point mutations at predicted N-glycosylation sites and analyze mobility shifts using the antibody to identify functionally important modification sites.

• Mass spectrometry integration: Use SPCC737.05 for immunoprecipitation followed by MS analysis to precisely map glycosylation sites and glycan compositions, as supported by immunocapture MS strategies from antibody validation frameworks .

• Glycosylation inhibitors: Apply tunicamycin or other specific inhibitors while monitoring Sup11p function and localization with the antibody to determine glycosylation requirement for proper activity.

These approaches provide comprehensive characterization of Sup11p glycosylation patterns and their functional significance.

How can SPCC737.05 antibody be used in high-throughput screening for Sup11p interactors?

The SPCC737.05 antibody can be strategically employed in high-throughput screening approaches to identify novel Sup11p interactors through several advanced methodologies:

• Antibody-based protein microarrays: Immobilize the SPCC737.05 antibody on microarray surfaces to capture Sup11p complexes from cell lysates, then identify interacting partners via fluorescent labeling and detection systems.

• Automated co-immunoprecipitation coupled with mass spectrometry: Implement robotics-assisted immunoprecipitation using the SPCC737.05 antibody across multiple conditions (cell cycle stages, stress responses), followed by LC-MS/MS to identify condition-specific interactors.

• Proximity-dependent labeling: Use the antibody to validate BioID or APEX2 fusion constructs of Sup11p, ensuring proper expression and localization before proximity labeling experiments to identify neighboring proteins in living cells.

• Yeast two-hybrid validation: After Y2H screening identifies potential interactors, use the SPCC737.05 antibody in co-immunoprecipitation or proximity ligation assays to validate interactions in native cellular contexts.

• FRET-based interaction screening: Combine fluorescently-tagged candidate proteins with immunofluorescence using SPCC737.05 antibody to screen for proximal interactions through automated microscopy platforms.

These high-throughput approaches accelerate discovery while the antibody serves as both a screening tool and validation method for confirming genuine interactions.

What are the recommended Western blotting conditions for optimal SPCC737.05 antibody performance?

For optimal Western blotting performance with the SPCC737.05 antibody, researchers should implement the following protocol refinements:

• Sample preparation: Lyse S. pombe cells in a buffer containing 50 mM Tris-HCl (pH 7.5), 150 mM NaCl, 1% Triton X-100, and protease inhibitor cocktail. Include 1 mM PMSF to prevent protein degradation.

• Protein loading: Load 20-50 μg of total protein per lane. Excess protein can increase background while insufficient protein may lead to weak signal.

• Gel selection: Use 10-12% SDS-PAGE gels for optimal resolution of Sup11p, which has a predicted molecular weight reflecting its membrane protein characteristics.

• Transfer conditions: Transfer to PVDF membranes (preferred over nitrocellulose) at 100V for 1 hour in transfer buffer containing 20% methanol and 0.05% SDS to facilitate transfer of membrane proteins.

• Blocking: Block membranes with 5% non-fat dry milk in TBST (TBS with 0.1% Tween-20) for 1 hour at room temperature. BSA-based blocking may be tested if background issues persist.

• Antibody dilution: Use the SPCC737.05 antibody at a 1:500 to 1:1000 dilution in blocking buffer. Incubate overnight at 4°C with gentle agitation.

• Washing: Wash membranes 4 times for 5 minutes each with TBST.

• Signal detection: For HRP-conjugated secondary antibodies, use enhanced chemiluminescence substrates with exposure times starting at 30 seconds, adjusting as needed .

These conditions should be optimized for each laboratory's specific equipment and requirements.

How should immunofluorescence protocols be adapted for SPCC737.05 antibody in S. pombe studies?

For optimal immunofluorescence results using the SPCC737.05 antibody in S. pombe studies, researchers should implement these specialized protocol adaptations:

• Cell fixation: Fix S. pombe cells with 3.7% formaldehyde for 30 minutes at room temperature, followed by treatment with 1.2M sorbitol in phosphate buffer. This maintains cell wall integrity while allowing antibody penetration.

• Cell wall digestion: Treat fixed cells with Zymolyase-100T (0.5 mg/ml) for 15-30 minutes at 37°C, monitoring digestion microscopically to prevent over-digestion while ensuring sufficient permeabilization.

• Blocking solution: Use 2% BSA with 0.1% Triton X-100 in PBS for 1 hour at room temperature. Adding 5% normal goat serum can further reduce background.

• Antibody dilution: Apply SPCC737.05 antibody at 1:100 to 1:250 dilution in blocking buffer. Incubate overnight at 4°C in a humid chamber.

• Washing steps: Perform 6 washes of 5 minutes each with PBS containing 0.1% Triton X-100 to minimize background.

• Secondary antibody: Use fluorophore-conjugated anti-rabbit antibodies at 1:500 dilution, incubating for 1 hour at room temperature protected from light.

• Nuclear counterstaining: Include DAPI (1 μg/ml) during the final wash to visualize nuclei.

• Mounting: Mount with antifade reagent containing 90% glycerol and 0.1% p-phenylenediamine to minimize photobleaching.

These adjustments accommodate the unique cell wall characteristics of S. pombe while maximizing specific signal from the SPCC737.05 antibody.

What approaches help resolve non-specific binding issues with SPCC737.05 antibody?

When encountering non-specific binding with the SPCC737.05 antibody, researchers can implement several targeted troubleshooting approaches:

• Titration optimization: Systematically test antibody dilutions from 1:250 to 1:2000 to identify the optimal concentration that maintains specific signal while minimizing background.

• Alternative blocking agents: If conventional blocking with BSA or milk proteins is insufficient, try specialized blocking agents such as fish gelatin (2-5%), casein (0.5-2%), or commercial synthetic blocking reagents designed for problematic antibodies.

• Pre-absorption strategy: Pre-incubate the SPCC737.05 antibody with excess recombinant GST (without the Sup11p fusion) to absorb any anti-GST antibodies that may be present in the polyclonal preparation.

• Buffer modifications: Increase the salt concentration in washing buffers (up to 300-500 mM NaCl) to disrupt low-affinity non-specific interactions. Adding 0.1-0.5% Triton X-100 or 0.05% Tween-20 can also reduce hydrophobic non-specific binding.

• Cross-adsorption: Pass the antibody through an affinity column containing immobilized total protein from a Sup11p knockout strain to remove antibodies that bind to other yeast proteins.

• Sequential epitope exposure: For fixed samples, try antigen retrieval methods with citrate buffer (pH 6.0) at 95°C for 15 minutes to expose epitopes that may enhance specific binding.

These approaches, applied systematically, can significantly improve the signal-to-noise ratio and enhance experimental reliability .

How can researchers implement the "five pillars" of antibody validation for SPCC737.05?

Researchers can comprehensively validate the SPCC737.05 antibody by implementing the "five pillars" approach as follows:

• Genetic strategies: Since Sup11p is essential for viability, create a conditional repression system using the nmt1 promoter or an auxin-inducible degron system for S. pombe. Compare antibody signals before and after depletion via Western blot and immunofluorescence to confirm specificity .

• Orthogonal strategies: Correlate protein detection using the SPCC737.05 antibody with mRNA levels measured by RT-qPCR or RNA-seq under various conditions. Additionally, create a GFP-tagged Sup11p strain and compare GFP fluorescence patterns with immunofluorescence using the antibody .

• Independent antibody strategies: Generate or obtain a second antibody targeting a different epitope of Sup11p. Compare localization and expression patterns between antibodies – concordant results strongly support specificity .

• Recombinant expression strategies: Overexpress Sup11p using a strong promoter (e.g., adh1) or in heterologous systems, then confirm increased signal intensity proportional to expression levels using the antibody .

• Immunocapture MS strategies: Immunoprecipitate using SPCC737.05 antibody followed by mass spectrometry analysis. Enrichment of Sup11p peptides with minimal off-target proteins confirms specificity .

Implementing these complementary validation approaches generates robust evidence for antibody specificity and performance characteristics across different experimental contexts.

What quantification methods should be used with SPCC737.05 antibody for reproducible results?

For generating reproducible quantitative data using the SPCC737.05 antibody, researchers should implement these specialized quantification approaches:

These approaches significantly enhance data reproducibility and allow meaningful comparison between different studies using the SPCC737.05 antibody.

What are common causes of weak signal when using SPCC737.05 antibody?

When encountering weak signal issues with the SPCC737.05 antibody, several factors may be responsible:

• Protein expression levels: Sup11p may be expressed at low endogenous levels, particularly in certain growth phases. Consider synchronizing cultures to capture peak expression periods or implementing a mild overexpression system to confirm antibody functionality.

• Epitope accessibility: The target epitope may be masked due to protein conformation or interactions. Try multiple sample preparation methods, including different detergents (CHAPS, DDM, or NP-40) for membrane protein extraction, as Sup11p has membrane localization characteristics.

• Fixation effects: For immunofluorescence, test different fixation protocols. Formaldehyde can sometimes mask epitopes; try shorter fixation times (10-15 minutes) or alternative fixatives like methanol-acetone mixtures.

• Antibody storage issues: Repeated freeze-thaw cycles can reduce activity. Aliquot antibody upon receipt and store at -20°C in the recommended buffer containing 50% glycerol. For working solutions, store at 4°C with 0.02% sodium azide to prevent microbial growth.

• Detection system sensitivity: For challenging samples, switch to more sensitive detection methods such as tyramide signal amplification (TSA) for immunofluorescence or high-sensitivity chemiluminescent substrates for Western blotting.

• Sample degradation: Sup11p may be susceptible to proteolysis. Ensure complete protease inhibitor cocktails are used, samples are kept cold, and processing time is minimized. Consider adding extra protease inhibitors specific for membrane proteins.

Addressing these factors systematically can significantly improve signal strength and experimental reliability.

How does SPCC737.05 antibody performance compare between different S. pombe strains?

The performance of SPCC737.05 antibody can vary significantly between different S. pombe strains due to several biological and technical factors:

• Genetic background effects: Wild-type strains (972h-, 975h+) typically show consistent antibody performance, but derivative strains may exhibit variations in Sup11p expression levels or post-translational modifications that affect epitope recognition. Laboratory-evolved strains may contain mutations that subtly alter antibody binding.

• Growth condition sensitivity: When comparing strains, standardize growth conditions (medium composition, temperature, growth phase) as Sup11p expression and localization patterns may vary with physiological state.

• Cell wall differences: Strains with mutations affecting cell wall composition (e.g., aah3Δ, pmi1Δ) may require modified cell permeabilization protocols for immunofluorescence to ensure consistent antibody access to intracellular epitopes.

• Strain-specific protocol adjustments: For protease-deficient strains (e.g., pep4Δ), reduce protease inhibitor concentrations. For autophagy-deficient strains (e.g., atg1Δ), expect potentially higher baseline Sup11p levels due to reduced protein turnover.

• Quantification considerations: When comparing strains, implement strain-specific loading controls or total protein normalization, as housekeeping gene expression may vary between genetic backgrounds .

• Validation strategy: For each new strain background, re-validate antibody specificity using at least one of the "five pillars" approaches, preferably using genetic approaches with controllable expression systems .

These considerations are essential for accurately interpreting strain-specific differences versus technical artifacts when using the SPCC737.05 antibody across different genetic backgrounds.

What are the best practices for SPCC737.05 antibody storage and handling to maintain activity?

To maintain optimal activity of the SPCC737.05 antibody over time, researchers should implement these specialized storage and handling practices:

• Initial processing: Upon receipt, centrifuge the antibody vial briefly before opening to collect liquid that may have dispersed during shipping.

• Aliquoting strategy: Divide the antibody into 10-20 μl single-use aliquots in sterile microcentrifuge tubes to prevent repeated freeze-thaw cycles. Use screw-cap tubes with O-rings to prevent evaporation during long-term storage.

• Storage temperature: Store aliquots at -20°C as recommended. Avoid storing in frost-free freezers which undergo temperature fluctuation cycles. For very long-term storage, -80°C may offer better activity preservation.

• Working solution handling: When preparing diluted working solutions, use high-quality BSA (IgG-free, protease-free) at 1-5 mg/ml as a carrier protein to prevent antibody adsorption to tube walls.

• Buffer composition: The antibody is supplied in 50% glycerol/50% PBS at pH 7.4 with 0.03% Proclin 300 as preservative. Maintain this buffer composition when diluting to prevent destabilization.

• Contamination prevention: Always use clean pipette tips and sterile technique when handling the antibody to prevent microbial contamination.

• Thawing procedure: Thaw frozen aliquots rapidly at room temperature and place on ice immediately after thawing. Avoid repeated temperature fluctuations.

• Activity monitoring: Consider including a standard positive control sample in experiments to track antibody performance over time. Any unexpected decrease in signal intensity may indicate antibody deterioration.

Following these practices will help maintain antibody activity and ensure consistent experimental results over extended research periods.

How can multiplexed assays be designed using SPCC737.05 antibody with other markers?

Designing effective multiplexed assays with SPCC737.05 antibody requires careful consideration of compatibility factors:

• Antibody species selection: Since SPCC737.05 is a rabbit antibody, pair it with primary antibodies raised in different host species (mouse, rat, goat) for co-detection. This allows the use of species-specific secondary antibodies with distinct fluorophores.

• Fluorophore separation: Select fluorophores with minimal spectral overlap (e.g., Alexa 488, Cy3, Alexa 647). If using confocal microscopy, configure sequential scanning to further minimize bleed-through between channels.

• Epitope compatibility: When co-staining with other antibodies targeting Sup11p-associated proteins, verify that fixation and permeabilization conditions remain optimal for all antibodies in the panel.

• Sequential immunostaining: For challenging combinations, implement sequential staining protocols with a glycine elution step (100 mM, pH 2.5) or other gentle elution buffer between rounds to prevent cross-reactivity.

• Cell cycle markers: Combine SPCC737.05 with cell cycle markers (e.g., anti-Cdc13 for G2/M) to correlate Sup11p dynamics with cell cycle progression. Implement image analysis algorithms that segment cells by cycle stage for population-specific quantification.

• Organelle co-localization: Pair with markers for cellular compartments like ER (anti-Bip1), Golgi (anti-Anp1), or cell wall (calcofluor white) to precisely map Sup11p localization through cellular structure.

• Protein-protein interaction detection: Implement proximity ligation assays (PLA) by combining SPCC737.05 with antibodies against suspected interaction partners to visualize protein complexes in situ with sub-diffraction resolution.

These strategies enable sophisticated multi-parameter analyses of Sup11p in relation to other cellular components and processes.

How should researchers interpret changes in Sup11p localization versus expression level?

When analyzing experimental results with the SPCC737.05 antibody, researchers must carefully distinguish between changes in Sup11p localization versus expression levels:

• Quantitative differentiation: For Western blot analysis, total protein levels reflect expression changes, while subcellular fractionation can reveal redistribution between compartments. Normalize each fraction to compartment-specific markers rather than to total Sup11p to accurately assess redistribution .

• Microscopy interpretation: In immunofluorescence, distinguish between intensity changes (expression) and pattern changes (localization) by implementing:

  • Whole-cell integrated intensity measurements for expression level changes

  • Coefficient of variation of pixel intensities for distribution pattern changes

  • Pearson's correlation coefficient with organelle markers for localization shifts

• Temporal considerations: Rapid changes (minutes to hours) often represent localization shifts or post-translational modifications, while slower changes (hours to days) typically reflect transcriptional regulation of expression levels.

• Stress response versus homeostasis: Under acute stress conditions, relocalization often precedes expression changes as an immediate response mechanism. Document both immediate (0-60 minutes) and sustained (2-24 hours) changes to capture this temporal relationship.

• Functional correlation: Correlate localization changes with phenotypic outcomes using specific assays for cell wall integrity, septum formation, or glycosylation function to determine the functional significance of observed changes.

• Statistical thresholds: Establish statistical thresholds for biological significance - typically >30% change for expression levels and >15% change for localization patterns, based on inherent variability in these measurements.

These interpretation frameworks help researchers extract meaningful biological insights from complex experimental data using the SPCC737.05 antibody.