Phospho-ITPR1 (S1598) Antibody

What is ITPR1 and what is the significance of its phosphorylation at S1598?

ITPR1 (Inositol 1,4,5-trisphosphate receptor type 1) is an intracellular receptor that functions as a calcium channel. Upon binding of inositol 1,4,5-trisphosphate (IP3), it mediates calcium release from the endoplasmic reticulum (ER). The phosphorylation at serine 1598 is an important post-translational modification that regulates ITPR1 function .

Specifically, phosphorylation at S1598 affects:

This phosphorylation site is located in the regulatory domain of ITPR1, making antibodies that specifically recognize this phosphorylation state valuable for studying the functional regulation of this calcium channel .

What are the primary applications for Phospho-ITPR1 (S1598) Antibody?

Phospho-ITPR1 (S1598) Antibody has been validated for several research applications:

These applications enable researchers to detect endogenous levels of ITPR1 protein specifically when phosphorylated at S1598, making it a valuable tool for studying signal transduction pathways related to calcium signaling .

What is the molecular weight of ITPR1 and what should I expect on Western blots?

ITPR1 is a large protein with a calculated molecular weight of approximately 313,929 Da (often referred to as ~314 kDa) . When running Western blots, researchers should observe a band at approximately 315 kDa . The large size of this protein requires special considerations:

• Use low percentage gels (4-6%)

• Extended transfer times may be necessary

• Large molecular weight markers should be included

• The protein may be sensitive to degradation, resulting in multiple bands

Some experimental protocols may require gradient gels for optimal separation and visualization of this high molecular weight protein .

How should I validate the specificity of Phospho-ITPR1 (S1598) Antibody in my experimental system?

Proper validation of phospho-specific antibodies is critical for experimental rigor. Consider the following approaches:

What are the optimal storage conditions for maintaining antibody activity?

For optimal performance and longevity of the Phospho-ITPR1 (S1598) Antibody:

The antibody is typically supplied in a buffer containing PBS with 50% glycerol, 0.5% BSA, and 0.02% sodium azide, which helps maintain stability. Importantly:

• Avoid repeated freeze-thaw cycles as they can degrade antibody performance

• Aliquot the antibody upon first thaw if multiple uses are anticipated

• Before use, allow the antibody to equilibrate to room temperature

• Centrifuge briefly to collect all liquid at the bottom of the vial .

How do I troubleshoot weak or absent signal when using this antibody in IHC or IF applications?

If you encounter weak or no signal when using Phospho-ITPR1 (S1598) Antibody, consider the following troubleshooting steps:

• Antigen retrieval optimization: Try different antigen retrieval methods:

  • Heat-induced epitope retrieval in citrate buffer (pH 6.0)

  • Alternative buffers such as EDTA (pH 8.0) or Tris-EDTA

  • Extending retrieval time from 10 to 20 minutes

• Antibody concentration: Adjust antibody dilution to a more concentrated range (e.g., 1:50 for IHC if 1:100 shows weak signal)

• Incubation conditions:

  • Extend primary antibody incubation (overnight at 4°C)

  • Optimize temperature (4°C vs. room temperature)

• Signal amplification: Consider using signal amplification systems:

  • Biotin-streptavidin

  • Tyramide signal amplification

  • Polymer-based detection systems

• Phosphorylation state: Confirm whether experimental conditions maintain the phosphorylation at S1598, as standard fixation may lead to dephosphorylation .

How can I use Phospho-ITPR1 (S1598) Antibody to investigate calcium signaling dynamics in neurological disorders?

ITPR1 plays a crucial role in neurological disorders, particularly spinocerebellar ataxias (SCA15, SCA16, SCA29) and other conditions featuring calcium dysregulation. To investigate these processes:

• Brain slice immunohistochemistry: Apply the antibody to fixed brain tissues from disease models to map regional patterns of ITPR1 phosphorylation changes.

• Co-localization studies: Combine with markers for ER stress (BiP/GRP78), neuronal subtypes, or apoptosis markers to correlate phosphorylation with specific cellular processes.

• Temporal studies: Track changes in phosphorylation status across disease progression in animal models.

• Calcium imaging correlation: After imaging calcium dynamics with fluorescent indicators (Fluo-4, GCaMP), fix and stain the same cells to correlate functional calcium release with ITPR1 phosphorylation.

• Drug response: Monitor how therapeutic interventions affect ITPR1 phosphorylation status in parallel with behavioral or physiological improvements .

What is the relationship between ITPR1 phosphorylation at S1598 and its interaction with other proteins in signaling complexes?

The phosphorylation of ITPR1 at S1598 regulates its participation in signaling complexes and protein-protein interactions. Key methodological approaches to study these relationships include:

• Co-immunoprecipitation: Use Phospho-ITPR1 (S1598) Antibody for immunoprecipitation followed by Western blotting for interacting partners, comparing phosphorylated vs. non-phosphorylated states.

• Proximity ligation assay (PLA): Visualize and quantify interactions between phosphorylated ITPR1 and partner proteins at the single-molecule level in situ.

• FRET/BRET approaches: Monitor real-time interaction dynamics using fluorescence/bioluminescence resonance energy transfer between tagged ITPR1 and partners.

• Phosphomimetic mutants: Create S1598D (phosphomimetic) and S1598A (non-phosphorylatable) ITPR1 mutants to study how this site affects protein complex formation.

• Hydrogen-deuterium exchange mass spectrometry: Compare structural dynamics of phosphorylated vs. non-phosphorylated ITPR1 to identify conformational changes that affect protein interactions .

How does ITPR1 phosphorylation at S1598 influence its role in cancer cell survival and metabolism?

ITPR1 phosphorylation status affects calcium signaling that regulates cancer cell proliferation, apoptosis resistance, and metabolic reprogramming. To investigate these aspects:

• Cancer cell line panel analysis: Evaluate baseline phospho-ITPR1 levels across diverse cancer cell lines to identify correlations with aggressiveness or therapeutic resistance.

• Metabolic stress response: Examine how nutrient deprivation, hypoxia, or other metabolic stressors alter S1598 phosphorylation and calcium homeostasis.

• Mitochondria-ER contact sites: Study how phosphorylation affects ITPR1 localization to mitochondria-associated membranes (MAMs) using subcellular fractionation and confocal microscopy.

• Cell death pathways: Correlate phosphorylation status with resistance to apoptosis, autophagy efficiency, or susceptibility to necroptosis.

• Combination with metabolic tracers: Integrate phospho-ITPR1 analysis with metabolic flux measurements using isotope-labeled nutrients to link calcium signaling with metabolic pathways .

How should I design experiments to study dynamic changes in ITPR1 phosphorylation at S1598 during cellular signaling events?

When investigating dynamic phosphorylation changes at S1598, consider the following experimental design approaches:

• Time-course analysis: Collect samples at multiple time points (seconds to hours) after stimulus application:

  • Short intervals (15s, 30s, 1min, 2min, 5min) for rapid responses

  • Longer intervals (15min, 30min, 1h, 3h, 6h) for sustained responses

• Stimulus titration: Vary the concentration of agonists (e.g., hormones, growth factors) to establish dose-response relationships.

• Upstream kinase manipulation: Use specific inhibitors or activators of kinases suspected to target S1598:

  • PKA (Protein Kinase A) inhibitors/activators

  • CaMKII inhibitors/activators

  • Cell-permeable cAMP analogs

• Phosphatase inhibitors: Include phosphatase inhibitors in lysis buffers to preserve phosphorylation status during sample preparation:

  • Sodium orthovanadate (1-2 mM)

  • β-glycerophosphate (10-20 mM)

  • Sodium fluoride (10-50 mM)

• Single-cell analysis: Combine with flow cytometry or quantitative microscopy to assess cell-to-cell variability in phosphorylation responses .

What controls should be included when using Phospho-ITPR1 (S1598) Antibody for analysis of clinical samples?

When analyzing clinical specimens with Phospho-ITPR1 (S1598) Antibody, include these essential controls:

• Tissue-specific positive controls: Include tissues known to express high levels of phosphorylated ITPR1:

  • Cerebellar Purkinje cells

  • Specific neuronal populations

  • Other validated positive control tissues

• Total ITPR1 measurement: Run parallel analysis with an antibody recognizing total ITPR1 regardless of phosphorylation status to normalize for total protein expression.

• Phosphatase-treated control: Treat a duplicate sample with lambda phosphatase to confirm the signal is phosphorylation-dependent.

• Peptide competition: Run a competition assay with the phosphopeptide used as immunogen.

• Technical controls:

  • Secondary antibody-only control to assess non-specific binding

  • Isotype control to evaluate antibody class-related background

  • FFPE or frozen specimen-specific protocol validation

• Inter-specimen standardization: Include reference standards across batches to normalize between different processing runs .

How can Phospho-ITPR1 (S1598) Antibody be incorporated into multiplexed analysis systems?

Multiplexed detection involving Phospho-ITPR1 (S1598) Antibody enables more comprehensive signaling pathway analysis. Consider these methodological approaches:

• Fluorescent multiplexing in microscopy:

  • Select compatible fluorophores with minimal spectral overlap

  • Use sequential staining protocols for antibodies raised in the same species

  • Consider tyramide signal amplification to allow antibody stripping and re-probing

  • Recommended combinations:

    • Phospho-ITPR1 (Alexa 488) + ER markers (Alexa 568) + nuclear stain (DAPI)

• Mass cytometry (CyTOF):

  • Conjugate the antibody with rare earth metals

  • Validate metal-tagged antibody performance versus untagged version

  • Include in panels with other phospho-specific antibodies targeting related pathways

• Multiplex immunoblotting:

  • Use fluorescent secondary antibodies of different wavelengths

  • Sequential probing with stripping between antibodies

  • Digital multiplexing platforms (e.g., DigiWest, Jess systems)

• Single-cell Western blot approaches:

  • Microfluidic platforms for analyzing phosphorylation at single-cell resolution

  • Correlate with other signaling markers in the same cells

• Spatial proteomics platforms:

  • Digital spatial profiling technologies

  • Multiplex immunofluorescence with multispectral imaging .

How can Phospho-ITPR1 (S1598) Antibody be used to study ITPR1's role in autoimmune neurological disorders?

ITPR1 has been identified as an autoantigen in certain neurological disorders. To investigate this connection:

• Patient sample analysis: Compare phosphorylated ITPR1 levels in:

  • CSF samples from patients with autoimmune cerebellar ataxia

  • Tissue biopsies from affected regions

  • Control samples from non-affected individuals

• Auto-antibody/phosphorylation relationship: Determine whether patient autoantibodies preferentially recognize the phosphorylated form of ITPR1:

  • Conduct immunoprecipitation with patient sera followed by Phospho-ITPR1 antibody detection

  • Compare binding to phosphorylated versus non-phosphorylated recombinant ITPR1

• Functional impact assessment: Evaluate how autoantibodies affect S1598 phosphorylation:

  • Incubate cultured cells with patient IgG

  • Measure changes in phosphorylation state

  • Correlate with calcium signaling alterations

• Treatment monitoring: Track phosphorylation changes in response to immunotherapies:

  • Before/after plasma exchange

  • During intravenous immunoglobulin treatment

  • With immunosuppressive therapies .

What is the significance of ITPR1 phosphorylation in spinocerebellar ataxias and how can this antibody contribute to understanding disease mechanisms?

ITPR1 mutations are associated with spinocerebellar ataxias (SCA15, SCA16, SCA29). To investigate phosphorylation's role:

• Mutation-specific effects: Compare S1598 phosphorylation patterns between:

  • Wild-type ITPR1

  • Disease-causing mutants

  • Using both cell models and patient-derived samples

• Developmental analysis: Examine phosphorylation during cerebellar development in:

  • Animal models of SCAs

  • Normal development

  • Human cerebellar organoids

• Calcium signaling correlation:

  • Measure calcium transients with fluorescent indicators

  • Correlate with phosphorylation status in the same cells

  • Evaluate how disease mutations alter this relationship

• Therapeutic testing: Use the antibody to evaluate whether experimental treatments normalize phosphorylation patterns:

  • Small molecules targeting calcium homeostasis

  • Gene therapy approaches

  • RNA-based therapeutics

• Biomarker potential: Assess whether phospho-ITPR1 levels in accessible samples correlate with disease progression or severity .

How does ITPR1 phosphorylation at S1598 differ between primary tumors and metastases, and what are the implications for cancer progression?

To investigate phospho-ITPR1's role in cancer metastasis:

What are the optimal fixation and antigen retrieval protocols for detecting phosphorylated ITPR1 in different tissue types?

Preserving phospho-epitopes requires careful optimization of fixation and retrieval methods:

Additional optimization strategies:

• Include phosphatase inhibitors in fixatives (1mM sodium orthovanadate, 10mM sodium fluoride)

• Consider ethanol-based fixation for better phospho-epitope preservation

• Test microwave vs. pressure cooker-based retrieval methods

• For particularly sensitive phospho-epitopes, consider vapor fixation methods

• For frozen sections, acetone or methanol fixation may better preserve phosphorylation .

How can I quantitatively analyze Phospho-ITPR1 (S1598) levels in immunofluorescence or immunohistochemistry images?

For rigorous quantification of phospho-ITPR1 immunostaining:

• Image acquisition standardization:

  • Use identical exposure settings across all samples

  • Include fluorescence calibration standards

  • Capture multiple fields per sample (minimum 5-10)

  • Use hardware that provides linear signal response

• Analysis approaches:

  • Mean fluorescence intensity measurement in defined regions

  • Integrated density (area × mean intensity)

  • Nuclear/cytoplasmic ratio quantification

  • Co-localization coefficients with organelle markers

• Software options:

  • ImageJ/FIJI with built-in analysis tools

  • CellProfiler for automated cell-by-cell analysis

  • QuPath for tissue section analysis

  • Commercial platforms like Definiens or Halo

• Normalization strategies:

  • Normalize to total ITPR1 signal from parallel sections

  • Use internal control regions within the same sample

  • Include reference standards across all experiments

• Statistical analysis:

  • Account for nested data structure (multiple cells within fields, multiple fields within samples)

  • Consider non-parametric approaches if data distribution is non-normal

  • Use appropriate multiple comparison corrections .

How can I adapt protocols to detect phosphorylated ITPR1 in difficult samples like cerebrospinal fluid or formalin-fixed paraffin-embedded (FFPE) archival tissues?

Working with challenging sample types requires specialized protocols:

For CSF samples:

• Concentrate proteins using:

  • Ultrafiltration (10 kDa MWCO filters)

  • TCA precipitation

  • Acetone precipitation

• Add phosphatase inhibitors immediately upon collection

• Consider dot blot approaches rather than Western blot due to low protein quantity

• Use high-sensitivity detection methods (ECL Advance, Clarity Max)

• Consider immunoprecipitation to enrich phosphorylated ITPR1 before analysis

For FFPE archival tissues:

• Optimize antigen retrieval:

  • Extended retrieval times (up to 40 minutes)

  • Test multiple pH conditions (pH 6.0, 8.0, 9.0)

  • Consider dual retrieval protocols (heat followed by enzymatic)

• Signal amplification systems:

  • Polymer-based detection systems

  • Tyramide signal amplification

  • Multiple antibody layer techniques

• Reduce background:

  • Extended blocking (overnight at 4°C)

  • Use specialized blockers for FFPE tissues

  • Include image processing to reduce autofluorescence

• Tissue age considerations:

  • Adjust protocols based on block age

  • Cut fresh sections rather than using stored slides

  • Consider RNAscope-based approaches if protein detection fails .

How might ITPR1 phosphorylation at S1598 contribute to neurodegenerative diseases beyond spinocerebellar ataxias?

While ITPR1 mutations are established in certain ataxias, phosphorylation dysregulation may impact other neurodegenerative processes:

• Research methodology for Alzheimer's disease connections:

  • Co-stain for phospho-ITPR1 and Aβ plaques/tau tangles

  • Examine temporal relationships between calcium dysregulation and pathology progression

  • Study effects of familial AD mutations on ITPR1 phosphorylation

• Parkinson's disease applications:

  • Investigate ITPR1 phosphorylation in dopaminergic neurons

  • Study interactions with α-synuclein

  • Examine mitochondrial calcium homeostasis in PD models

• Amyotrophic Lateral Sclerosis (ALS) investigations:

  • Compare phospho-ITPR1 patterns in motor neurons of ALS models vs. controls

  • Assess correlation with ER stress markers

  • Evaluate potential as therapeutic target

• Experimental design considerations:

  • Use phospho-specific antibodies in postmortem human tissues with short PMI

  • Develop temporal studies in animal models at pre-symptomatic and symptomatic stages

  • Consider cell-type specific analyses using laser capture microdissection .

What role does ITPR1 phosphorylation play in mitochondrial calcium dynamics and how might this impact cellular bioenergetics?

ITPR1 localizes to ER-mitochondria contact sites, where phosphorylation status may regulate organelle calcium exchange:

• Dual organelle calcium imaging approaches:

  • Use targeted calcium indicators (mito-GCaMP, ER-LAR-GECO)

  • Correlate real-time calcium transfers with phosphorylation state

  • Assess impact of phosphomimetic mutations

• Bioenergetic analysis methodology:

  • Measure oxygen consumption rate and extracellular acidification

  • Assess mitochondrial membrane potential

  • Quantify ATP production

  • Correlate with phosphorylation status

• Proximity analysis techniques:

  • Quantify ER-mitochondria contact sites using split fluorescent proteins

  • Use super-resolution microscopy to map phospho-ITPR1 at contact sites

  • Apply FRET sensors to measure local calcium concentrations

• Manipulation strategies:

  • Use optogenetic tools to trigger calcium release

  • Employ phosphatase/kinase modulators to alter S1598 phosphorylation

  • Evaluate mitochondrial morphology changes

  • Assess impacts on metabolic flexibility .

How might artificial intelligence and machine learning approaches enhance the analysis of phospho-ITPR1 distribution patterns in complex tissues?

Advanced computational approaches can reveal subtle patterns in phospho-ITPR1 distribution:

• Deep learning for pattern recognition:

  • Train convolutional neural networks to identify cell-type specific phosphorylation patterns

  • Develop multi-class segmentation to distinguish subcellular localization

  • Apply generative adversarial networks to enhance low-quality images

• Multiparametric analysis methods:

  • Integrate phospho-ITPR1 data with other biomarkers

  • Apply dimensional reduction techniques (t-SNE, UMAP)

  • Identify novel cellular phenotypes through unsupervised clustering

• Spatial analysis approaches:

  • Quantify neighborhood relationships between differently phosphorylated cells

  • Apply spatial statistics to identify tissue microdomains

  • Correlate with functional parameters

• Implementation strategies:

  • Use publicly available frameworks (TensorFlow, PyTorch)

  • Develop transfer learning from existing cell segmentation models

  • Create specialized analytical pipelines for specific tissue types

  • Validate computational findings with traditional biochemical approaches .