Phospho-VCP (S352) Antibody

What is Phospho-VCP (S352) Antibody and what does it specifically detect?

Phospho-VCP (S352) Antibody is a rabbit polyclonal antibody that specifically recognizes the Valosin-containing protein (VCP) only when phosphorylated at serine 352. This antibody has high specificity for the phosphorylated form and does not cross-react with non-phosphorylated VCP protein. It detects endogenous levels of phosphorylated VCP at position S352 in human, mouse, and rat samples .

The antibody is typically generated using a synthesized peptide derived from human VCP around the phosphorylation site of S352, commonly spanning the amino acid region 318-367 . This targeted approach ensures specificity for the phosphorylated form of the protein.

What are the validated applications for Phospho-VCP (S352) Antibody?

Based on multiple vendor validations, Phospho-VCP (S352) Antibody has been validated for:

• Western Blot (WB) applications at dilutions ranging from 1:500 to 1:2000

• ELISA applications at a recommended dilution of 1:5000

These applications have been confirmed with human, mouse, and rat samples .

How should Phospho-VCP (S352) Antibody be stored to maintain optimal activity?

For optimal storage and longevity of the antibody:

• Store at -20°C for long-term storage (up to 1 year from the date of receipt)

• For frequent use and short-term storage, 4°C is acceptable for up to one month

• Avoid repeated freeze-thaw cycles which can compromise antibody quality and performance

• The antibody is formulated in PBS containing 50% glycerol, 0.5% BSA, and 0.02% sodium azide, which helps maintain stability

What positive controls should be used to validate Phospho-VCP (S352) Antibody specificity?

When validating the specificity of Phospho-VCP (S352) Antibody, consider the following positive controls:

• 22RV1 cell lysates have been validated as a positive control showing detectable levels of phosphorylated VCP at S352, as demonstrated in vendor validation data

• NIH/3T3 cells subjected to starvation for 24 hours have shown increased phosphorylation of VCP at S352

For conclusive validation, researchers should:

• Run parallel samples with both phosphorylated and non-phosphorylated states

• Include a phosphatase treatment control to confirm phospho-specificity

• Use blocking peptides (phospho and non-phospho) to confirm epitope specificity

How can I optimize Western blot conditions for Phospho-VCP (S352) Antibody?

For optimal Western blot results with Phospho-VCP (S352) Antibody:

• Sample preparation:

  • Use phosphatase inhibitors in lysis buffers to preserve phosphorylation status

  • Maintain cold conditions during sample processing to minimize dephosphorylation

• Blocking conditions:

  • Use 5% BSA in TBST rather than milk, as milk contains phosphatases that may reduce signal

  • Block for 1 hour at room temperature or overnight at 4°C

• Antibody incubation:

  • Start with a 1:1000 dilution in 5% BSA/TBST

  • Incubate overnight at 4°C for optimal binding

• Detection:

  • VCP has a molecular weight of approximately 89 kDa (calculated MW)

  • Compatible secondary antibodies include Goat Anti-Rabbit IgG conjugated to HRP, AP, Biotin, or FITC

What are the key considerations when designing experiments to study VCP phosphorylation dynamics?

When studying VCP phosphorylation dynamics, consider:

• Stimulation conditions:

  • Nutrient deprivation (starvation) increases VCP phosphorylation at S352

  • Monitor time-course changes following stimulation

• Inhibitor studies:

  • Use kinase inhibitors to identify the responsible kinase for S352 phosphorylation

  • Use phosphatase inhibitors to preserve phosphorylation status

• Functional correlation:

  • Design experiments to correlate S352 phosphorylation with VCP's known functions:

    • Vesicle transport and fusion

    • 26S proteasome function

    • Peroxisome assembly

    • Mitotic regulation

    • Ubiquitin-dependent protein degradation

• Subcellular localization:

  • Determine if phosphorylation alters VCP's cellular distribution using fractionation techniques alongside Western blot analysis

How does phosphorylation at S352 affect VCP's functional properties and interactions?

VCP (p97) is a member of the AAA ATPase family involved in numerous cellular processes. Phosphorylation at S352 may affect:

• ATPase activity:

  • S352 is positioned near the ATP-binding domain, potentially modulating enzymatic activity

  • Researchers should consider ATP hydrolysis assays to measure changes in activity

• Protein-protein interactions:

  • VCP forms complexes with multiple cofactors including UFD1, NPLOC4, and Hsc70

  • Phosphorylation might alter these interactions, affecting downstream functions

  • Co-immunoprecipitation experiments using the phospho-specific antibody can reveal differential binding partners

• Subcellular localization:

  • VCP distributes between the cytoplasm, ER, and other organelles

  • S352 phosphorylation may regulate this distribution

  • Immunofluorescence using the phospho-specific antibody can track localization changes

What methodological approaches can be used to study the relationship between VCP phosphorylation and disease pathology?

To investigate VCP phosphorylation in disease contexts:

• Patient sample analysis:

  • Compare phospho-VCP levels in patient samples vs. controls using Western blot

  • Correlate phosphorylation status with disease severity or progression

• Disease models:

  • Analyze phospho-VCP in cellular or animal models of diseases where VCP is implicated:

    • ALS (Amyotrophic Lateral Sclerosis)

    • IBMPFD (Inclusion Body Myopathy with Paget's disease and Frontotemporal Dementia)

    • CMT2Y (Charcot-Marie-Tooth Disease Type 2Y)

• Phospho-mimetic/phospho-dead mutants:

  • Generate S352D (phospho-mimetic) or S352A (phospho-dead) VCP mutants

  • Assess functional consequences in cellular assays

  • Rescue experiments in VCP-depleted backgrounds

• Kinase/phosphatase modulation:

  • Identify and manipulate the kinases/phosphatases regulating S352 phosphorylation

  • Assess effects on disease-relevant cellular phenotypes

What techniques can be combined with Phospho-VCP (S352) Antibody for comprehensive analysis of VCP function?

For comprehensive analysis of phosphorylated VCP function:

• Proximity ligation assay (PLA):

  • Combine Phospho-VCP (S352) Antibody with antibodies against potential interacting partners

  • Visualize and quantify in situ protein-protein interactions

• ChIP-seq or RNA-seq analysis:

  • Investigate transcriptional changes associated with altered VCP phosphorylation status

  • Identify pathways regulated by phospho-VCP

• Mass spectrometry:

  • Perform immunoprecipitation with Phospho-VCP (S352) Antibody followed by mass spectrometry

  • Identify novel interacting partners specific to the phosphorylated form

  • Map the complete phosphorylation profile of VCP in different conditions

• CRISPR-based approaches:

  • Generate S352 knock-in mutations in endogenous VCP

  • Assess phenotypic consequences of altered phosphorylation

What are common issues encountered when using Phospho-VCP (S352) Antibody in Western blot and how can they be resolved?

Common issues and solutions:

• Weak or no signal:

  • Ensure phosphatase inhibitors are included in all buffers

  • Increase antibody concentration (try 1:500 dilution)

  • Extend primary antibody incubation time to overnight at 4°C

  • Use enhanced chemiluminescent substrates for greater sensitivity

  • Verify sample handling to preserve phosphorylation status

• High background:

  • Increase washing steps (5×5 minutes with TBST)

  • Prepare fresh blocking solution

  • Ensure secondary antibody is highly cross-adsorbed

  • Reduce secondary antibody concentration

• Multiple bands:

  • Verify if bands represent different phosphorylated forms of VCP

  • Run phosphatase-treated controls to confirm phospho-specificity

  • Optimize SDS-PAGE conditions for better separation

• Inconsistent results:

  • Standardize lysate preparation protocols

  • Normalize loading with total protein staining methods

  • Maintain consistent transfer conditions across experiments

How can phosphatase treatment controls be designed to validate antibody phospho-specificity?

To validate phospho-specificity:

• Sample preparation:

  • Prepare identical protein samples in duplicate

  • Treat one set with lambda phosphatase or calf intestinal phosphatase

  • Maintain the other set in phosphatase inhibitor-containing buffer

• Treatment conditions:

  • Lambda phosphatase: 400 units per 100 μg protein, 30°C for 30 minutes

  • CIP: 10 units per 100 μg protein, 37°C for 1 hour

• Western blot analysis:

  • Run treated and untreated samples side by side

  • Probe with Phospho-VCP (S352) Antibody

  • The signal should be significantly reduced or eliminated in phosphatase-treated samples

• Additional controls:

  • Probe duplicate blots with total VCP antibody to confirm equal loading

  • Include phosphatase inhibitor controls to verify enzyme effectiveness

What cellular processes are regulated by VCP phosphorylation at S352?

VCP phosphorylation at S352 may regulate several critical cellular processes:

• Endoplasmic reticulum-associated degradation (ERAD):

  • VCP facilitates extraction of misfolded proteins from the ER

  • Phosphorylation may modulate this activity, affecting proteostasis

• Mitotic progression:

  • VCP is necessary for Golgi fragmentation during mitosis and reassembly afterward

  • S352 phosphorylation might be cell cycle-regulated

  • Study phosphorylation status across different cell cycle phases

• Protein quality control:

  • The NPLOC4-UFD1-VCP complex regulates degradation of ubiquitinated proteins

  • Phosphorylation may affect complex formation or activity

  • Assay ubiquitin-dependent degradation in cells expressing phospho-mimetic/dead mutants

• Membrane fusion events:

  • VCP participates in membrane fusion and transitional ER formation

  • Phosphorylation might regulate these activities

  • Monitor organelle morphology in cells with altered S352 phosphorylation status

How does VCP S352 phosphorylation compare with other known VCP post-translational modifications?

VCP undergoes multiple post-translational modifications that affect its function:

• Comparative analysis:

  • S352 phosphorylation occurs in a region distinct from other major phosphorylation sites

  • Design experiments to compare the functional effects of different modifications:

    • Phosphorylation at other sites (e.g., Y805)

    • Acetylation

    • Ubiquitination

    • SUMOylation

• Crosstalk between modifications:

  • Investigate whether S352 phosphorylation affects other modifications

  • Use mass spectrometry approaches to map the complete modification landscape

  • Develop targeted assays to detect specific combinations of modifications

• Signaling pathway integration:

  • Identify kinases responsible for S352 phosphorylation

  • Map the upstream signaling pathways leading to this modification

  • Compare with pathways regulating other VCP modifications

What research models are most appropriate for studying VCP phosphorylation dynamics?

Optimal research models include:

• Cell culture systems:

  • 22RV1 cells show detectable levels of phosphorylated VCP at S352

  • NIH/3T3 cells exhibit starvation-induced phosphorylation

  • Consider cell types relevant to VCP-associated diseases:

    • Neurons for neurodegenerative conditions

    • Muscle cells for myopathies

    • Osteoclasts for Paget's disease

• Animal models:

  • Transgenic mice expressing phospho-mutant forms of VCP (S352A/D)

  • Disease models where VCP function is implicated:

    • ALS models

    • IBMPFD models

    • Proteotoxic stress models

• Patient-derived systems:

  • iPSC-derived cells from patients with VCP mutations

  • Primary cells from patients with VCP-associated diseases

  • Analysis of phosphorylation status in relation to disease phenotypes

Technical Specifications of Available Phospho-VCP (S352) Antibodies

VCP Protein Information and Characteristics