Phospho-ITGB1 (Y795) Antibody

What is Phospho-ITGB1 (Y795) Antibody and what does it specifically detect?

Phospho-ITGB1 (Y795) Antibody is a research-grade antibody that specifically detects endogenous levels of integrin beta-1 protein only when phosphorylated at tyrosine 795. It is typically produced by immunizing rabbits with synthetic phosphopeptides derived from the sequence surrounding the Y795 phosphorylation site (P-K-Y(p)-E-G) of human ITGB1 . This site-specific phosphorylation represents an important post-translational modification involved in integrin signaling pathways.

The antibody is generally produced as a polyclonal preparation and purified via affinity chromatography using epitope-specific phosphopeptides. Non-phospho-specific antibodies are typically removed by chromatography using non-phosphopeptides to ensure specificity .

What experimental applications are suitable for Phospho-ITGB1 (Y795) Antibody?

Common research applications include:

For Western blotting applications, researchers often use extracts from UV-treated MCF7 cells as positive controls, as UV treatment has been demonstrated to induce ITGB1 phosphorylation at Y795 .

What is the biological significance of integrin β1 phosphorylation at Y795?

Integrin β1 (CD29) functions as part of heterodimeric transmembrane receptors involved in cell-matrix adhesion and signal transduction. The Y795 residue is located within one of two highly conserved NPxY motifs in the cytoplasmic domain that serve as binding sites for phosphotyrosine-binding (PTB) domain-containing proteins .

Research indicates that phosphorylation at Y795 plays a critical role in:

• Mediating interactions with cytoskeletal and signaling proteins

• Regulating cell migration and invasion processes

• Modulating integrin activation states and downstream signaling

Interestingly, in vivo studies have demonstrated that while tyrosine phosphorylation is dispensable for normal integrin function (as shown in Y-to-F mutants), the tyrosine residues themselves are essential (as demonstrated by non-functional Y-to-A mutants) . This suggests that the structural features of these residues, rather than their phosphorylation state, may be the primary determinant of integrin function during normal development.

How do Y-to-F versus Y-to-A mutations in integrin β1 differentially affect its function?

Genetic studies have revealed striking functional differences between phenylalanine (F) and alanine (A) substitutions at the conserved tyrosine residues (including Y795) in integrin β1:

Research has shown that Itgb1^YF/YF mice (containing phenylalanine substitutions at Y783 and Y795) develop normally and are fertile, indicating that tyrosine phosphorylation of integrin β1 is not essential for its in vivo function during development . In contrast, Itgb1^YA/YA embryos (with alanine substitutions) die during embryonic development, demonstrating that while phosphorylation may be dispensable, the tyrosine residues themselves are crucial for integrin function .

These findings suggest that structural features of these tyrosine residues, likely their ability to engage in hydrophobic interactions with PTB domain-containing proteins, are more critical than their phosphorylation state during normal development.

What is the relationship between integrin β1 phosphorylation and cancer progression?

Integrin β1 signaling has been implicated in various aspects of tumor biology:

• Lung Cancer Models: Studies show that cells containing Y-to-A mutations at residues Y783 and Y795 in integrin β1 (KO.YYAA) produced no colonies in soft agar, suggesting these residues are critical for anchorage-independent growth .

• Signaling Mechanisms: Integrin β1 supports cancer progression through:

  • Activation of focal adhesion kinase (FAK)

  • Stimulation of ERK and AKT signaling pathways

  • Promotion of cell migration and invasion

Research using single-cell RNA sequencing of tumor models has demonstrated that tumors maintain integrin β1 expression even when normal cells show decreased expression, suggesting selective pressure for its retention in cancer cells .

Treatment of cancer cells with inhibitors targeting FAK, AKT, or ERK significantly reduces colony formation, indicating that these pathways are critical mediators of integrin β1-dependent tumor growth .

What methodological considerations are important when using Phospho-ITGB1 (Y795) Antibody?

For optimal experimental outcomes, researchers should consider:

• Sample Preparation:

  • Use freshly prepared lysates when possible

  • Include phosphatase inhibitors in lysis buffers to preserve phosphorylation state

  • Consider stimulating cells (e.g., with UV treatment ) to increase phosphorylation levels

• Antibody Validation:

  • Implement appropriate controls: phosphatase-treated samples (negative control) and samples from cells with known ITGB1 phosphorylation (positive control)

  • Consider using Y795F mutant cells as specificity controls

• Detection Optimization:

  • Western blot: Optimize transfer conditions for high-molecular-weight proteins (88-150 kDa range)

  • Use optimized blocking agents to minimize background

  • For immunohistochemistry applications, optimize antigen retrieval methods

• Technical Considerations:

  • Store antibody at -20°C with 50% glycerol to maintain stability

  • Avoid repeated freeze-thaw cycles

  • Typical working dilutions: 1:500-1:2000 for Western blot, 1:40000 for ELISA

How can In-Cell ELISA methodology enhance phospho-ITGB1 research?

The Phospho-Integrin Beta1 (Tyr795) In-Cell ELISA approach offers several advantages for studying ITGB1 phosphorylation dynamics:

• Advantages:

  • Enables measurement of phosphorylation directly in intact cells without requiring cell lysis

  • Provides higher throughput than Western blotting

  • Allows quantitative assessment of signaling pathway modulation

  • Can detect subtle changes in phosphorylation levels

• Applications:

  • Screening compounds that modulate integrin signaling

  • Studying temporal dynamics of phosphorylation events

  • Investigating signaling crosstalk between integrin and growth factor pathways

  • Assessing phosphorylation in response to extracellular matrix components

This technique is particularly valuable for studying the role of integrin β1 phosphorylation in cancer and inflammatory disorders, where it can serve as a biomarker for disease progression and potential therapeutic targeting .

How does integrin β1 signaling interact with growth factor receptor pathways?

Integrin β1 exhibits significant cross-talk with growth factor signaling pathways, particularly epidermal growth factor receptor (EGFR) signaling:

• Signaling Integration:

  • EGF treatment results in increased FAK, ERK, and AKT phosphorylation in cells expressing integrin β1

  • This effect is diminished in integrin β1-knockout cells, indicating cooperative signaling

• Mechanistic Interactions:

  Pathway	Observed Effect	Functional Significance
  FAK	Major reduction in both basal and EGF-induced activation in β1-KO cells	Critical mediator of growth and proliferation signals
  ERK	Decreased activation in β1-KO cells	Regulates cell cycle progression and gene expression
  AKT	Reduced phosphorylation in β1-KO cells	Mediates survival and metabolic signaling

• Therapeutic Implications:

  • FAK inhibitors (e.g., defactinib) show significant effects on colony formation in soft agar assays

  • Combined targeting of integrin and growth factor pathways may provide synergistic therapeutic benefits in cancer treatment

This integrative signaling is particularly relevant in cancer biology, where integrin β1-dependent FAK activation appears to be a major mechanism supporting tumor cell growth and proliferation.

What are the optimal conditions for detecting phospho-ITGB1 (Y795) in different experimental systems?

Optimal detection requires careful consideration of experimental parameters:

• Cell/Tissue Type Selection:

  • Human cell lines: MCF7, A549 commonly used

  • Mouse/rat tissues: Verify cross-reactivity before proceeding

• Stimulation Protocols:

  • UV treatment: Effective for inducing ITGB1 phosphorylation

  • Growth factor stimulation: Consider EGF treatment to study signaling cross-talk

  • Matrix engagement: Plating cells on specific ECM proteins can modulate phosphorylation

• Detection Method Selection:

  Method	Best For	Limitations
  Western Blot	Molecular weight confirmation, semi-quantitative analysis	Lower throughput
  ELISA	Quantitative measurement across multiple samples	Less information about protein size
  IHC	Spatial distribution in tissues	Potentially lower specificity
  In-Cell ELISA	High-throughput screening, pathway analysis	Limited to cultured cells

• Controls and Validation:

  • Phosphatase treatment: Confirms phospho-specificity

  • Competing peptide: Validates epitope specificity

  • Genetic models: Y795F mutants as negative controls

How can mutation analysis techniques be applied to study the functional significance of Y795 phosphorylation?

Several experimental approaches can elucidate the functional role of Y795 phosphorylation:

• Site-Directed Mutagenesis Approaches:

  • Y795F mutation: Prevents phosphorylation while maintaining structure

  • Y795A mutation: Disrupts both phosphorylation and structure

  • Y795E mutation: Phosphomimetic to simulate constitutive phosphorylation

• Genetic Models:

  • Knock-in mouse models with specific mutations at Y795

  • CRISPR/Cas9-generated cell lines with Y795 mutations

• Functional Assays to Assess Impact:

  • Adhesion assays on various matrix components

  • Migration/invasion assays

  • Soft agar colony formation for transformed phenotype assessment

  • Signaling pathway activation (FAK, ERK, AKT phosphorylation)

• Advanced Analysis Techniques:

  • Proteomics approaches to identify phosphorylation-dependent binding partners

  • Live-cell imaging with phospho-specific biosensors

  • Single-cell analysis to examine heterogeneity in phosphorylation states

These approaches have revealed that while Y795F mutations (preventing phosphorylation) are compatible with normal development and function, Y795A mutations cause severe functional deficits, highlighting the complexity of integrin signaling mechanisms beyond simple phosphorylation events .

What are common challenges when working with phospho-specific antibodies and how can they be addressed?

Researchers frequently encounter the following challenges:

• Low Signal Intensity:

  • Ensure phosphatase inhibitors are included in all buffers

  • Optimize stimulation conditions to maximize phosphorylation

  • Consider phospho-enrichment approaches before analysis

  • Increase antibody concentration or incubation time

• High Background Signal:

  • Optimize blocking conditions (consider different blocking agents)

  • Increase washing stringency

  • Titrate antibody concentration

  • Use phosphopeptide competition to confirm specificity

• Variability Between Experiments:

  • Standardize lysate preparation protocols

  • Include internal loading controls

  • Consider normalizing to total ITGB1 levels

  • Maintain consistent stimulation parameters

• Cross-Reactivity Issues:

  • Validate specificity using phosphatase treatment

  • Use knockout or Y795F mutant cells as negative controls

  • Consider developing validation standards for each new lot of antibody

How can phospho-ITGB1 (Y795) analysis be integrated with broader phosphoproteomic approaches?

Integration with broader phosphoproteomic strategies enhances research depth:

• Complementary Approaches:

  • Mass spectrometry-based phosphoproteomics for unbiased discovery

  • Antibody-based methods for targeted validation

  • Proximity ligation assays to study phosphorylation-dependent protein interactions

• Multiplexed Analysis:

  • Simultaneous detection of multiple phosphorylation sites (Y783, Y795)

  • Correlation with other integrin signaling components (FAK, Src, ILK)

  • Analysis of phosphorylation dynamics across signaling networks

• Systems Biology Integration:

  • Pathway analysis incorporating phosphorylation data

  • Computational modeling of integrin signaling networks

  • Multi-omics approaches combining phosphoproteomics with transcriptomics

• Emerging Technologies:

  • Single-cell phosphoproteomic analysis

  • CRISPR screens combined with phospho-specific readouts

  • Spatial phosphoproteomics in tissue sections

This integrated approach provides a more comprehensive understanding of ITGB1 phosphorylation in the context of broader cellular signaling networks.

What are emerging research areas involving phospho-ITGB1 (Y795)?

Several cutting-edge research directions are currently developing:

• Therapeutic Targeting:

  • Development of small molecules targeting specific phosphorylation-dependent interactions

  • Design of peptide mimetics to disrupt phosphorylation-dependent protein binding

  • Combination approaches targeting integrin and growth factor pathways

• Advanced Imaging:

  • Super-resolution microscopy to visualize phosphorylation in focal adhesions

  • FRET-based biosensors for real-time phosphorylation monitoring

  • Correlative light-electron microscopy for ultrastructural analysis

• Disease Relevance:

  • Role in cancer metastasis and therapy resistance

  • Involvement in fibrotic disorders and tissue remodeling

  • Potential implications in inflammatory and immune disorders

• Technological Innovations:

  • Development of more sensitive and specific phospho-antibodies

  • Nanobody-based detection systems

  • CRISPR-based endogenous tagging for phosphorylation monitoring