Phospho-ITGB4 (Tyr1510) Antibody

What is the function of ITGB4 and why is its phosphorylation at Tyr1510 significant?

Integrin beta-4 (ITGB4) functions as a key component in cell adhesion and migration processes. It serves as a receptor for laminin and plays a critical structural role in the hemidesmosome of epithelial cells. ITGB4 is required for the regulation of keratinocyte polarity and motility, and forms heterodimers with integrin alpha-6 .

Phosphorylation of ITGB4 at tyrosine 1510 (Tyr1510) is particularly significant because:

• It serves as a molecular switch for signal transduction pathways

• It plays a crucial role in growth factor-induced signaling that contributes to tumorigenesis

• Phosphorylation at this specific site has been linked to cancer cell migration and invasion

• It regulates downstream MEK1-ERK1/2 signaling cascades that control cell behavior

Research has demonstrated that p-ITGB4-Y1510 levels are significantly increased in pancreatic cancer tissues compared to normal pancreatic tissues, and high expression correlates with local invasion and distant metastasis .

What applications are Phospho-ITGB4 (Tyr1510) antibodies suitable for?

Phospho-ITGB4 (Tyr1510) antibodies are versatile research tools applicable to multiple experimental techniques:

These antibodies specifically detect endogenous levels of ITGB4 protein only when phosphorylated at Tyr1510, allowing researchers to distinguish the phosphorylated form from total ITGB4 . They typically show reactivity with human, mouse, and rat samples, making them suitable for cross-species comparative studies .

How does phosphorylation of ITGB4 at Tyr1510 differ from phosphorylation at other tyrosine residues in ITGB4?

ITGB4 contains multiple tyrosine phosphorylation sites with distinct regulatory functions:

• Tyr1510 phosphorylation: Primarily involved in MEK1-ERK1/2 pathway activation. Studies have shown that phosphorylation at this site is specifically linked to pancreatic cancer cell migration and invasion through regulation of MEK1 (T292) and ERK1/2 .

• Tyr1422 and Tyr1440 phosphorylation: These sites are more associated with PLCγ1 binding. Research using phosphopeptide pulldown experiments confirmed the interaction of PLCγ1 with pY1422 and pY1440, suggesting different downstream signaling events than those triggered by Tyr1510 phosphorylation .

• Tyr1343 and Tyr1349 phosphorylation: Mutation studies have shown that these tyrosine residues contribute to total ITGB4 tyrosine phosphorylation. When all four tyrosines (Y1343, Y1349, Y1422, and Y1440) were mutated, ITGB4 tyrosine phosphorylation was almost undetectable .

An important methodological consideration is that EGFR activation can induce phosphorylation of multiple tyrosine residues in ITGB4, but the Src Family Kinases (SFKs) appear to have different effects on different phosphorylation sites . This differential regulation suggests site-specific functions of tyrosine phosphorylation in ITGB4.

What is the relationship between ITGB4 Tyr1510 phosphorylation and cancer progression across different tumor types?

The relationship between ITGB4 Tyr1510 phosphorylation and cancer progression varies across tumor types:

Pancreatic Cancer:

• High p-ITGB4-Y1510 expression correlates with local invasion and distant metastasis

• Associated with poor patient survival

• Regulates cancer cell migration and invasion through MEK1-ERK1/2 signaling

Breast Cancer:

• Immunohistochemical analysis has detected elevated p-ITGB4-Y1510 levels in breast carcinoma tissue

• Western blot validation confirms specificity of this phosphorylation in breast cancer models

Pan-Cancer Analysis:

• A comprehensive study across 33 tumor types from TCGA demonstrated that while ITGB4 is highly expressed in many cancers, phosphorylation patterns vary

• Interestingly, reduced phosphorylation of ITGB4 at S1457 (a different site) was observed in several tumors, including breast and ovarian cancers

• This suggests that different phosphorylation sites may have distinct roles in different cancer types

The mechanistic relationship appears to involve:

• Growth factor receptor activation (e.g., EGFR)

• Tyrosine phosphorylation of ITGB4 at Y1510

• Activation of downstream MEK1-ERK1/2 signaling

• Enhanced cell migration and invasion

• Contribution to metastatic potential

What are the best practices for validating specificity of Phospho-ITGB4 (Tyr1510) antibodies in experimental systems?

To ensure the specificity and validity of results when using Phospho-ITGB4 (Tyr1510) antibodies, researchers should implement the following validation strategies:

Validation Method 1: Peptide Competition Assay

• Pre-incubate the antibody with the immunizing phosphopeptide

• Compare results with and without peptide competition

• Specific signals should be blocked by the phosphopeptide

Validation Method 2: Phosphatase Treatment

• Treat one sample set with phosphatase before antibody incubation

• Specific phospho-signals should be eliminated after phosphatase treatment

Validation Method 3: Genetic Validation

• Use ITGB4 knockdown (siRNA or CRISPR) to validate specificity

• Generate cells expressing the ITGB4-Y1510A mutant (tyrosine to alanine substitution)

• The antibody should not detect this mutant form

Validation Method 4: Stimulation/Inhibition Approach

• Stimulate cells with Na₂VO₃ (phosphatase inhibitor) to increase tyrosine phosphorylation

• Use specific kinase inhibitors to block phosphorylation

• Western blot analysis should show increased/decreased signals as expected

Scientific data supports these approaches. For example, Western blot analysis of lysates from HepG2 cells treated with Na₂VO₃ showed clear detection of phosphorylated ITGB4, which was abolished when the antibody was blocked with the immunizing peptide .

How can I optimize immunohistochemistry protocols for detecting Phospho-ITGB4 (Tyr1510) in different tissue types?

Optimizing immunohistochemistry (IHC) protocols for Phospho-ITGB4 (Tyr1510) requires careful consideration of tissue-specific factors:

Antigen Retrieval Optimization:

• For formalin-fixed paraffin-embedded (FFPE) tissues: Test both heat-induced epitope retrieval (HIER) methods

  • Citrate buffer (pH 6.0) for moderate retrieval

  • EDTA buffer (pH 9.0) for stronger retrieval

• For phospho-epitopes like p-ITGB4-Y1510, EDTA buffer often provides better results

Antibody Concentration Titration:

• Begin with the manufacturer's recommended dilution range (typically 1:50-1:300 for IHC)

• Perform a dilution series to identify optimal signal-to-noise ratio

• For pancreatic cancer tissues, research demonstrates successful staining at 1:100 dilution

Blocking and Detection Systems:

• Use 3-5% BSA or 5-10% normal serum for blocking

• For phospho-epitopes: Add phosphatase inhibitors (e.g., sodium fluoride, sodium orthovanadate) to all buffers

• For chromogenic detection: HRP-polymer detection systems typically provide better sensitivity than ABC methods

Tissue-Specific Considerations:

• Breast carcinoma: Validated positive control with clear membrane/cytoplasmic staining patterns

• Pancreatic cancer: Shows distinct patterns in invasive vs. normal tissue

• Background reduction in pancreatic tissue may require additional blocking with avidin/biotin if using biotin-based detection systems

Validation Controls:

• Always include a negative control section incubated with antibody pre-absorbed with immunizing phosphopeptide

• Include known positive tissues based on published research (e.g., breast carcinoma)

How should I design experiments to investigate the role of ITGB4 Tyr1510 phosphorylation in cancer cell migration and invasion?

When designing experiments to study ITGB4 Tyr1510 phosphorylation in cancer cell migration and invasion, consider this comprehensive approach:

1. Cell Model Selection and Validation:

• Choose cell lines with documented ITGB4 expression (e.g., PC-1.0, AsPC-1 for pancreatic cancer studies)

• Validate baseline ITGB4 and p-ITGB4-Y1510 expression by Western blot

• Consider using both high-invasive and low-invasive cell lines for comparison

2. Genetic Manipulation Strategies:

• ITGB4 knockdown: siRNA or shRNA targeting ITGB4

• Site-specific mutation: Generate ITGB4-Y1510A (tyrosine to alanine) mutant to specifically block phosphorylation at this site

• Overexpression: Wild-type ITGB4 vs. Y1510A mutant

3. Functional Assays:

• Migration assays: Transwell, wound healing (scratch assay)

• Invasion assays: Matrigel-coated transwell chambers

• Adhesion assays: Cell adhesion to laminin or other ECM components

• 3D culture assays: Spheroid formation and invasion into surrounding matrix

4. Signaling Pathway Analysis:

• Examine MEK1-ERK1/2 pathway activation:

  • Measure p-MEK1 (T292), p-MEK1 (T386), p-MEK2 (T394), and p-ERK1/2 levels

  • Use specific MEK/ERK inhibitors to validate pathway involvement

• Investigate additional potential downstream effectors

5. Experimental Controls:

• Positive control: EGF or other growth factor stimulation known to induce ITGB4 phosphorylation

• Negative control: Phosphatase treatment, kinase inhibitors

• Specificity control: Compare Y1510A mutant with mutations at other tyrosine sites (Y1422, Y1440)

Suggested Experimental Flow:

• Establish baseline p-ITGB4-Y1510 levels across cell panel

• Generate genetic models (knockdown, Y1510A mutant)

• Perform functional assays comparing wild-type vs. modified cells

• Analyze signaling pathway activation

• Validate key findings with pharmacological inhibitors

Published research has demonstrated that ITGB4-Y1510A transfection significantly reduced migration and invasion of PC-1.0 and AsPC-1 pancreatic cancer cells, while decreasing MEK1 (T292) and ERK1/2 phosphorylation levels .

What approaches can be used to study ITGB4 Tyr1510 phosphorylation in clinical samples and its correlation with patient outcomes?

To effectively investigate ITGB4 Tyr1510 phosphorylation in clinical samples and correlate with patient outcomes, consider the following comprehensive approach:

1. Clinical Sample Collection and Processing:

• Tissue types: Primary tumors, matched normal tissues, metastatic lesions

• Sample processing: FFPE sections, fresh frozen tissues, tissue microarrays (TMAs)

• Patient data collection: Clinical stage, treatment history, survival outcomes, recurrence data

2. Detection Methods for p-ITGB4-Y1510:

• Immunohistochemistry (IHC): Most common for FFPE samples

  • Validated antibody dilution: 1:50-1:100

  • Scoring system: Percentage of positive cells and staining intensity (0-3+)

• Multiplex immunofluorescence: For co-localization with other markers

• Phospho-protein arrays: For high-throughput screening

3. Validation and Controls:

• Peptide competition controls to confirm antibody specificity

• Technical replicates and inter-observer scoring

• Phosphatase-treated sections as negative controls

4. Correlation Analyses:

• p-ITGB4-Y1510 expression vs. clinicopathological features

  • Tumor stage, grade, invasion depth

  • Lymph node and distant metastasis

  • Local invasion patterns

• Survival analyses

  • Kaplan-Meier curves stratified by p-ITGB4-Y1510 expression

  • Univariate and multivariate Cox regression analyses

5. Representative Study Design:
Based on published research on pancreatic cancer :

6. Advanced Approaches:

• Combined analysis of multiple phosphorylation sites

• Integration with genomic and transcriptomic data

• Machine learning approaches to identify patterns associated with outcomes

Research has demonstrated that high p-ITGB4-Y1510 expression correlates with local invasion and distant metastasis of pancreatic cancer, while high total ITGB4 was significantly associated with poor survival of patients . Similar approaches could be applied to other cancer types.

How do I interpret conflicting results between total ITGB4 expression and Tyr1510 phosphorylation levels?

Interpreting discrepancies between total ITGB4 expression and Tyr1510 phosphorylation levels requires careful consideration of several biological and technical factors:

Biological Explanations for Discrepancies:

• Independent Regulation Mechanisms:

  • Total protein expression is regulated at transcriptional/translational levels

  • Phosphorylation is regulated by kinase/phosphatase activities

  • Research has shown that ITGB4-Y1510A mutation not only blocked phosphorylation but also suppressed total ITGB4 expression, suggesting interdependence

• Threshold Effects:

  • High total ITGB4 doesn't necessarily mean high phosphorylation

  • Kinase saturation or phosphatase activity may create nonlinear relationships

  • Pan-cancer analysis showed variable correlation between ITGB4 expression and phosphorylation across different tumor types

• Context-Dependent Signaling:

  • Growth factor availability varies between tissues/conditions

  • Phosphorylation at Tyr1510 depends on upstream signaling events

  • Different tyrosine sites (Y1422, Y1440, Y1343, Y1349) may compete for kinases

Technical Considerations:

• Antibody Specificity Assessment:

  • Validate phospho-antibody specificity with peptide competition

  • Confirm total ITGB4 antibody doesn't cross-react with other integrins

  • Consider phosphatase treatment controls

• Normalization Approaches:

  • Calculate phospho-to-total ratio (p-ITGB4/total ITGB4)

  • Use appropriate housekeeping proteins for each measurement

  • Consider analyzing multiple samples/replicates

• Sample Handling Effects:

  • Phosphorylation can be lost during sample processing

  • Include phosphatase inhibitors in all buffers

  • Match fixation conditions across samples

Case Study Interpretation Example:
In pancreatic cancer research, while both total ITGB4 and p-ITGB4-Y1510 were elevated in tumor tissues, high p-ITGB4-Y1510 specifically correlated with invasion and metastasis, whereas high total ITGB4 was associated with poor survival . This suggests distinct but complementary roles, where:

What are the implications of ITGB4 Tyr1510 phosphorylation on downstream signaling pathways and potential therapeutic targeting?

The phosphorylation of ITGB4 at Tyr1510 has significant implications for downstream signaling and represents a potential therapeutic target with several important considerations:

Downstream Signaling Pathways Activated by p-ITGB4-Y1510:

• MEK1-ERK1/2 Pathway:

  • p-ITGB4-Y1510 specifically regulates MEK1 phosphorylation at T292

  • Mutation studies (ITGB4-Y1510A) showed decreased p-MEK1 (T292) and p-ERK1/2 levels

  • Notably, p-MEK1 (T386) and p-MEK2 (T394) were not affected by this mutation

  • This suggests a selective regulation of specific MEK-ERK phosphorylation events

• Potential Cross-Talk with Growth Factor Signaling:

  • ITGB4 forms heterodimers with integrin α6 that bind to NRG1, IGF1, and IGF2

  • These interactions are essential for NRG1-ERBB and IGF1/2 signaling

  • Phosphorylation at Y1510 may modulate these growth factor signaling pathways

• Distinct Functions from Other Phosphorylation Sites:

  • Different from Y1422/Y1440 phosphorylation, which facilitates PLCγ1 binding

  • Different from Y1343/Y1349 phosphorylation with yet undefined functions

  • Combined mutations suggest cooperative roles in signaling

Therapeutic Targeting Implications:

• Direct Targeting Strategies:

  • Selective inhibition of kinases responsible for Y1510 phosphorylation

  • Blocking antibodies targeting the phosphorylated epitope

  • Peptide mimetics that compete for downstream effector binding

• Combination Therapy Approaches:

  • Combining with MEK/ERK inhibitors for synergistic effects

  • Targeting both ITGB4 expression and its phosphorylation

  • Research shows targeting both could provide comprehensive inhibition of invasive phenotypes

• Biomarker Potential:

  • p-ITGB4-Y1510 as a predictive biomarker for MEK/ERK inhibitor sensitivity

  • Monitoring therapy response via changes in phosphorylation levels

  • Stratifying patients based on phosphorylation status

Clinical Development Considerations:

• Cancer Type Specificity:

  • Strong evidence for targeting in pancreatic cancer

  • Potential applications in breast cancer based on expression data

  • Pan-cancer analysis suggests tissue-specific regulation patterns

• Challenges and Limitations:

  • Phosphorylation-specific targeting is technically challenging

  • Potential for compensatory phosphorylation at other sites

  • Integrin redundancy may bypass inhibition

Research has conclusively demonstrated that "targeting ITGB4 or its phosphorylation at Y1510 may be a novel therapeutic option for pancreatic cancer" , providing strong rationale for further development of therapeutic strategies focused on this specific phosphorylation event.

What emerging technologies can enhance the study of ITGB4 Tyr1510 phosphorylation dynamics and function?

Several cutting-edge technologies show promise for advancing our understanding of ITGB4 Tyr1510 phosphorylation:

Advanced Imaging Approaches:

• Phospho-specific FRET sensors to monitor ITGB4 phosphorylation in real-time

• Super-resolution microscopy (STORM/PALM) to visualize nanoscale organization of phosphorylated ITGB4 in hemidesmosomes

• Live-cell imaging with genetically encoded biosensors to track phosphorylation dynamics during cell migration

Phosphoproteomics Innovations:

• Targeted mass spectrometry using parallel reaction monitoring (PRM) for absolute quantification of p-ITGB4-Y1510

• Proximity labeling combined with phosphoproteomics to identify proteins interacting specifically with phosphorylated ITGB4

• Single-cell phosphoproteomics to reveal heterogeneity in ITGB4 phosphorylation within tumor populations

Genetic Engineering Approaches:

• CRISPR base editing to introduce Y1510F mutations in endogenous ITGB4

• Optogenetic control of ITGB4 phosphorylation to study temporal dynamics

• Phospho-mimetic mutations (Y1510E/D) compared with phospho-null mutations (Y1510A/F) to dissect functional consequences

Computational Methods:

• Machine learning algorithms to predict functional consequences of ITGB4 phosphorylation across cancer types

• Network analysis integrating multi-omics data to position p-ITGB4-Y1510 in cancer signaling networks

• Molecular dynamics simulations to understand structural changes induced by Y1510 phosphorylation

These technologies could address key questions including temporal regulation of phosphorylation during cancer progression, identification of direct downstream effectors specific to p-ITGB4-Y1510, and development of more selective therapeutic approaches targeting this phosphorylation event.

How can we determine the relationship between different ITGB4 phosphorylation sites in coordinating cellular functions?

Understanding the interplay between different ITGB4 phosphorylation sites requires sophisticated experimental approaches:

Multiplexed Phosphorylation Analysis:

• Develop antibody panels targeting multiple phosphorylation sites simultaneously

• Use multiplexed immunofluorescence to visualize co-occurrence of different phosphorylation events

• Apply mass spectrometry to quantify stoichiometry of multiple phosphorylation sites

Sequential Phosphorylation Studies:

• Time-course experiments following growth factor stimulation

• Phosphatase inhibition combined with kinase activation to determine hierarchical relationships

• Site-specific mutations to determine whether phosphorylation at one site affects others

Functional Cooperation Experiments:

• Generate combinatorial mutations of phosphorylation sites (e.g., Y1510A/Y1422A)

• Compare single vs. double/triple mutations in migration, invasion, and signaling assays

• Research has already begun this approach by demonstrating that mutation of four tyrosine sites (Y1343, Y1349, Y1422, Y1440) has more profound effects than double mutations

Structural Biology Approaches:

• Determine crystal structures of ITGB4 cytoplasmic domain with different phosphorylation patterns

• Use NMR to analyze conformational changes induced by multiple phosphorylation events

• Model electrostatic and conformational changes with computational approaches