Phospho-PTPN6 (Tyr536) Antibody

What is the Phospho-PTPN6 (Tyr536) Antibody and what epitope does it recognize?

Phospho-PTPN6 (Tyr536) Antibody is a rabbit polyclonal antibody specifically designed to detect endogenous levels of SHP-1 (also known as PTPN6) only when phosphorylated at tyrosine 536 . The antibody recognizes a synthetic peptide sequence around the phosphorylation site of tyrosine 536 (S-E-Y(p)-G-N) derived from human SHP-1 . This specificity makes it valuable for studying the phosphorylation status of PTPN6 in various cellular contexts, as it won't cross-react with non-phosphorylated forms of the protein.

What is the molecular function of PTPN6/SHP-1 in cellular signaling?

PTPN6/SHP-1 is a tyrosine phosphatase enzyme that plays crucial roles in controlling immune signaling pathways and fundamental physiological processes such as hematopoiesis . It functions by:

• Dephosphorylating and negatively regulating several receptor tyrosine kinases (RTKs) including EGFR, PDGFR, and FGFR, thereby modulating their signaling activities

• When recruited to immunoreceptor tyrosine-based inhibitory motif (ITIM)-containing receptors (such as LILRB1, PDCD1, CD3D, CD22, and CLEC12A), it initiates their dephosphorylation and subsequently inhibits downstream signaling events

• Modulating signaling of several cytokine receptors including IL-4 receptor

• Targeting multiple cytoplasmic signaling molecules including STING1, LCK, and STAT1 involved in diverse cellular processes such as T-cell activation and cGAS-STING signaling

• Acting as a key transcriptional regulator of hepatic gluconeogenesis by controlling recruitment of RNA polymerase II to the PCK1 promoter together with STAT5A

What species reactivity does the Phospho-PTPN6 (Tyr536) Antibody demonstrate?

The Phospho-PTPN6 (Tyr536) Antibody demonstrates reactivity with human, mouse, and rat samples . This cross-species reactivity makes it versatile for comparative studies across different model organisms. Researchers should note that the epitope sequence recognized by this antibody is conserved across these species, allowing for consistent detection of the phosphorylated protein in various experimental systems.

What experimental applications is the Phospho-PTPN6 (Tyr536) Antibody validated for?

The Phospho-PTPN6 (Tyr536) Antibody has been validated for multiple experimental applications:

The antibody has been tested in these applications using multiple validation methods, including the use of blocking peptides to confirm specificity .

What is the recommended storage protocol for maintaining antibody activity?

Upon receipt, the Phospho-PTPN6 (Tyr536) Antibody should be stored at -20°C or -80°C to maintain its activity . Avoid repeated freeze-thaw cycles as this can degrade the antibody and reduce its effectiveness . The antibody is typically supplied at a concentration of 1.0 mg/mL in phosphate buffered saline (without Mg²⁺ and Ca²⁺), pH 7.4, containing 150mM NaCl, 0.02% sodium azide, and 50% glycerol . This formulation helps maintain stability during storage. For long-term storage (up to 1 year from the date of receipt), -20°C is recommended .

How should researchers optimize immunohistochemistry protocols using this antibody?

For optimal immunohistochemistry results with the Phospho-PTPN6 (Tyr536) Antibody:

• Begin with a dilution range of 1:50-1:100 as recommended by manufacturers .

• Use appropriate antigen retrieval methods based on tissue fixation protocols.

• Include proper negative controls, such as the same tissues probed with pre-immune serum or the antibody pre-incubated with blocking peptide .

• Consider using positive controls, such as human breast carcinoma tissue, which has been validated to show specific staining with this antibody .

• Optimize incubation times and washing steps to reduce background staining.

• Use appropriate detection systems compatible with rabbit polyclonal antibodies.

• Document any variations in staining intensity between different tissue types to establish baseline expectations for your specific samples.

How can the phosphorylation of PTPN6 at Tyr536 be utilized as a biomarker in immune function studies?

The phosphorylation of PTPN6/SHP-1 at Tyr536 serves as an important biomarker in immune function studies for several reasons:

• Tyr536 phosphorylation affects the enzymatic activity of SHP-1, with phosphorylation at this site enhancing its phosphatase activity .

• In immune cells, monitoring Tyr536 phosphorylation can provide insights into the activation state of inhibitory signaling pathways.

• Researchers can use this antibody to track dynamic changes in SHP-1 activity following receptor engagement or cytokine stimulation.

• In comparative studies of normal versus pathological immune responses, altered patterns of SHP-1 Tyr536 phosphorylation may indicate dysregulated immune signaling.

• The antibody can be used in multiplex analyses with other phospho-specific antibodies to map signaling networks in immune cells under various conditions.

This approach requires careful experimental design with appropriate stimulation conditions and time-course analyses to capture the dynamic nature of phosphorylation events.

What are effective strategies for multiplex analysis combining Phospho-PTPN6 (Tyr536) with other phospho-specific antibodies?

Effective multiplex analysis strategies include:

• Sequential immunoblotting: Strip and reprobe membranes with different phospho-specific antibodies, ensuring complete stripping between applications. Begin with the Phospho-PTPN6 (Tyr536) Antibody at 1:500-1:2,000 dilution .

• Multicolor immunofluorescence:

  • Select secondary antibodies with non-overlapping emission spectra

  • Use antibodies raised in different host species (the Phospho-PTPN6 (Tyr536) Antibody is raised in rabbit )

  • Optimize dilutions for each antibody (1:100-1:200 recommended for this antibody in IF applications )

  • Include appropriate controls for spectral overlap

• Phospho-flow cytometry:

  • Establish fixation and permeabilization conditions compatible with all target epitopes

  • Validate antibody performance in flow cytometry before multiplex analysis

  • Use isotype controls to determine background staining levels

• Mass cytometry (CyTOF):

  • Metal-conjugate the Phospho-PTPN6 (Tyr536) Antibody using commercial kits

  • Validate metal-conjugated antibody specificity using known positive controls

  • Create a panel with complementary signaling markers relevant to your research question

When designing multiplex experiments, consider the biological relationships between different phosphorylation events to create meaningful data interpretation frameworks.

How does phosphorylation at Tyr536 impact the regulatory function of PTPN6 in receptor tyrosine kinase signaling?

Phosphorylation of PTPN6/SHP-1 at Tyr536 significantly impacts its regulatory function in receptor tyrosine kinase (RTK) signaling:

• Tyr536 phosphorylation enhances the phosphatase activity of SHP-1, which directly affects its ability to dephosphorylate and negatively regulate RTKs such as EGFR, PDGFR, and FGFR .

• This phosphorylation may alter the protein's conformation, potentially relieving auto-inhibition and exposing the catalytic site.

• In RTK signaling contexts, increased Tyr536 phosphorylation can lead to more rapid signal termination due to enhanced SHP-1 activity against phosphorylated receptors.

• The dynamic balance between kinase-mediated phosphorylation and SHP-1-mediated dephosphorylation creates feedback loops that fine-tune signaling responses.

• Experimental manipulation of Tyr536 phosphorylation (through phosphatase inhibitors or kinase activators) can help elucidate these regulatory mechanisms in specific cellular contexts.

Researchers investigating these mechanisms should consider using complementary approaches, such as phospho-mimetic or phospho-deficient mutants of SHP-1 at Tyr536, alongside the antibody-based detection methods.

What are common issues with background signal in immunofluorescence and how can they be addressed?

Common background issues when using Phospho-PTPN6 (Tyr536) Antibody in immunofluorescence and their solutions include:

• Non-specific binding:

  • Increase blocking time (use 5-10% normal serum from the species of the secondary antibody)

  • Optimize antibody dilution (start with 1:100-1:200 as recommended )

  • Add 0.1-0.3% Triton X-100 in blocking buffer to reduce hydrophobic interactions

• High autofluorescence:

  • Use Sudan Black B (0.1-1%) treatment to quench autofluorescence

  • Consider spectral unmixing during image acquisition

  • Use appropriate tissue-specific autofluorescence quenching methods

• Cross-reactivity:

  • Pre-absorb the antibody with blocking peptide as a negative control

  • Select secondary antibodies with minimal cross-reactivity to the species being studied

  • Use isotype controls to determine background levels

• Fixation artifacts:

  • Optimize fixation methods (the antibody has been validated with methanol-fixed Hela cells )

  • Compare multiple fixation protocols to identify optimal conditions for epitope preservation

  • Consider short fixation times with freshly prepared fixatives

Always include appropriate positive controls (such as cell lines known to express phosphorylated PTPN6) and negative controls in experimental designs.

How can researchers validate the specificity of phospho-signal detection in various experimental systems?

To validate the specificity of phospho-signal detection using the Phospho-PTPN6 (Tyr536) Antibody:

• Peptide competition assay:

  • Pre-incubate the antibody with the phospho-peptide immunogen

  • Compare staining between blocked and unblocked antibody samples

  • Significant reduction in signal confirms specificity

• Phosphatase treatment control:

  • Treat duplicate samples with lambda phosphatase before antibody incubation

  • Loss of signal in treated samples confirms phospho-specificity

• Stimulation/inhibition experiments:

  • Use known inducers of PTPN6 phosphorylation as positive controls

  • Apply specific kinase inhibitors to reduce phosphorylation

  • Monitor signal changes that correlate with expected biology

• Genetic approaches:

  • Use PTPN6 knockdown/knockout systems as negative controls

  • Employ Tyr536 point mutants (Y536F) to create phospho-deficient controls

  • Complement with total PTPN6 antibody to confirm protein presence

• Cross-validation with other methods:

  • Confirm phosphorylation status using mass spectrometry

  • Use alternative phospho-specific antibodies (if available)

  • Compare results across multiple experimental platforms (e.g., WB, IF, IHC)

Document all validation steps methodically to establish confidence in experimental findings.

What are the critical considerations when quantifying Western blot results with this phospho-specific antibody?

When quantifying Western blot results using the Phospho-PTPN6 (Tyr536) Antibody, researchers should consider:

• Loading controls:

  • Use both total PTPN6 antibody (on stripped membranes or parallel blots) and housekeeping proteins

  • Calculate phospho-PTPN6/total PTPN6 ratios to normalize for expression differences

  • Ensure linear range detection for accurate quantification

• Signal normalization:

  • Include a standard sample across all blots for inter-blot comparisons

  • Use consistent exposure times for all experimental conditions

  • Apply appropriate background subtraction methods

• Dynamic range considerations:

  • Establish the linear range of antibody detection (using dilution series)

  • Optimize protein loading to ensure signal falls within this linear range

  • Use appropriate dilution of the antibody (1:500-1:2,000 recommended )

• Positive and negative controls:

  • Include samples with known high and low phosphorylation status

  • Consider using phosphatase-treated samples as negative controls

  • Use stimulated samples (with growth factors or cytokines) as positive controls

• Statistical approach:

  • Perform at least three independent biological replicates

  • Apply appropriate statistical tests based on experimental design

  • Report both fold changes and statistical significance

• Technical considerations:

  • Document complete methods including sample preparation, SDS-PAGE conditions, transfer parameters, and detection methods

  • Consider using fluorescent secondary antibodies for more precise quantification

  • Validate antibody lot-to-lot consistency for longitudinal studies

How does the phosphorylation status of PTPN6 Tyr536 change during immune cell activation and what are the functional consequences?

During immune cell activation, PTPN6/SHP-1 Tyr536 phosphorylation undergoes dynamic changes with significant functional consequences:

• In resting immune cells, basal levels of Tyr536 phosphorylation contribute to maintaining signaling thresholds through constitutive phosphatase activity.

• Upon immune receptor engagement (particularly inhibitory receptors containing ITIMs), Tyr536 phosphorylation increases, enhancing SHP-1's phosphatase activity . This serves as a negative feedback mechanism to prevent excessive immune activation.

• The functional consequences include:

  • Modulation of T-cell receptor signaling intensity and duration

  • Regulation of cytokine receptor responses, including IL-4 receptor signaling

  • Control of myeloid cell activation thresholds

  • Influence on NK cell cytotoxicity through regulation of activating and inhibitory receptor balance

• Dysregulation of this phosphorylation can contribute to immune pathologies:

  • Reduced Tyr536 phosphorylation may lower the threshold for immune activation, potentially contributing to autoimmunity

  • Excessive phosphorylation may impair normal immune responses against pathogens or tumors

Researchers investigating these dynamics should consider time-course experiments with appropriate cellular activation models and multiple readouts of immune function.

What is the relationship between PTPN6 Tyr536 phosphorylation and its interactions with ITIM-containing receptors?

The relationship between PTPN6/SHP-1 Tyr536 phosphorylation and its interactions with ITIM-containing receptors is complex and bidirectional:

• Recruitment mechanism: When ITIM-containing receptors (such as LILRB1, PDCD1/PD-1, CD22, and CLEC12A) are engaged by their ligands, their ITIMs become phosphorylated, creating docking sites for SHP-1 via its SH2 domains .

• Phosphorylation influence on binding affinity: Tyr536 phosphorylation may alter the conformation of SHP-1, potentially affecting its ability to bind to phosphorylated ITIMs. This creates a regulatory layer where SHP-1's recruitment efficiency depends on its own phosphorylation status.

• Activation upon recruitment: When recruited to ITIMs, SHP-1's phosphatase activity is enhanced, leading to dephosphorylation of nearby signaling molecules and subsequent inhibition of downstream signaling events .

• Feedback regulation: The phosphorylation of Tyr536 may be modulated by the very signaling pathways that SHP-1 regulates, creating feedback loops that fine-tune inhibitory receptor function.

• Therapeutic relevance: Understanding this relationship is crucial for developing immunomodulatory therapies targeting immune checkpoints, as many checkpoint receptors signal through ITIM-SHP-1 interactions.

Researchers exploring these interactions should consider co-immunoprecipitation studies combined with phospho-specific detection to track the dynamics of these molecular events in relevant immune contexts.

How does PTPN6 Tyr536 phosphorylation contribute to disease mechanisms in hematological disorders?

PTPN6/SHP-1 Tyr536 phosphorylation plays significant roles in disease mechanisms of several hematological disorders:

• Leukemias and lymphomas:

  • Altered Tyr536 phosphorylation may disrupt the balance between proliferation and differentiation signals in hematopoietic cells

  • Changes in SHP-1 phosphorylation status can affect its tumor suppressor functions through dysregulated RTK signaling

  • Therapeutic targeting of pathways that regulate Tyr536 phosphorylation represents a potential intervention strategy

• Autoimmune cytopenias:

  • Defects in SHP-1 Tyr536 phosphorylation may contribute to loss of tolerance mechanisms

  • Impaired negative regulation of B-cell and T-cell activation can lead to development of autoantibodies against blood cells

  • Monitoring Tyr536 phosphorylation could serve as a biomarker for treatment response

• Myeloproliferative disorders:

  • Dysregulated Tyr536 phosphorylation may alter SHP-1's ability to control cytokine receptor signaling

  • This can lead to hypersensitivity to growth factors and excessive proliferation of myeloid lineages

  • The phosphorylation status at this site may influence response to tyrosine kinase inhibitor therapies

• Immune thrombocytopenia:

  • Altered SHP-1 phosphorylation affects megakaryocyte development and platelet production

  • Dysregulation at Tyr536 may impact immune regulation in this autoimmune condition

  • Therapeutic strategies targeting this pathway could potentially restore normal platelet counts

Research in this area benefits from combining phospho-specific antibody-based analyses with functional studies in primary patient samples and relevant animal models of hematological diseases.

What novel techniques are being developed to study PTPN6 phosphorylation dynamics in live cells?

Novel techniques for studying PTPN6/SHP-1 phosphorylation dynamics in live cells include:

• Genetically encoded FRET-based biosensors:

  • These sensors can detect conformational changes in SHP-1 upon Tyr536 phosphorylation

  • Allow real-time visualization of phosphorylation events in living cells

  • Can be targeted to specific subcellular compartments to study localized regulation

• Phospho-specific nanobodies:

  • Developing small antibody fragments that specifically recognize phosphorylated Tyr536

  • These can be expressed intracellularly as fusion proteins with fluorescent tags

  • Enable tracking of endogenous phosphorylated SHP-1 without cell fixation

• Proximity labeling approaches:

  • Fusion of biotin ligases (BioID, TurboID) to SHP-1 interaction partners

  • Allows temporal mapping of protein interactions dependent on Tyr536 phosphorylation

  • Provides insights into dynamic signaling complexes formed around phosphorylated SHP-1

• Optogenetic control of kinases/phosphatases:

  • Light-inducible systems to manipulate enzymes that modify Tyr536 phosphorylation

  • Enables precise temporal control of SHP-1 phosphorylation status

  • Facilitates cause-effect studies linking phosphorylation to downstream signaling events

• Single-molecule imaging techniques:

  • Super-resolution microscopy combined with phospho-specific labeling

  • Tracking individual SHP-1 molecules to understand how phosphorylation affects mobility and clustering

  • Correlating molecular behavior with cellular responses

These emerging approaches complement traditional biochemical methods using the Phospho-PTPN6 (Tyr536) Antibody and provide new insights into the spatiotemporal regulation of this important signaling molecule.

How can computational modeling integrate phospho-PTPN6 data to predict signaling outcomes in complex immune networks?

Computational modeling can integrate phospho-PTPN6 data in several sophisticated ways:

• Ordinary differential equation (ODE) models:

  • Incorporate rate constants for Tyr536 phosphorylation and dephosphorylation

  • Model how phosphorylation affects SHP-1 enzymatic activity

  • Predict signaling dynamics across multiple time scales and perturbations

• Agent-based modeling approaches:

  • Simulate individual SHP-1 molecules with distinct phosphorylation states

  • Model molecular interactions dependent on phosphorylation status

  • Predict emergent cellular behaviors from molecular-level events

• Bayesian network analysis:

  • Integrate phospho-proteomics data including Tyr536 phosphorylation

  • Infer causal relationships between phosphorylation events in signaling cascades

  • Identify key regulatory nodes influenced by SHP-1 activity

• Machine learning approaches:

  • Train algorithms on phospho-proteomic datasets that include PTPN6 Tyr536 measurements

  • Identify patterns correlating phosphorylation status with cellular outcomes

  • Make predictions about cellular responses to novel stimuli or drug treatments

• Multi-scale modeling:

  • Connect molecular-level SHP-1 phosphorylation data to cell population behaviors

  • Model feedback loops between cellular responses and phosphorylation dynamics

  • Predict tissue-level immune responses based on phospho-SHP-1 status

Researchers implementing these approaches should validate computational predictions experimentally using the Phospho-PTPN6 (Tyr536) Antibody in conjunction with functional readouts of immune cell activity.

What are the implications of PTPN6 Tyr536 phosphorylation for developing targeted immunotherapies?

PTPN6/SHP-1 Tyr536 phosphorylation has several important implications for developing targeted immunotherapies:

• Checkpoint inhibitor enhancement:

  • Modulating Tyr536 phosphorylation could potentially enhance the efficacy of existing checkpoint inhibitors

  • Targeted reduction of SHP-1 activity in tumor-infiltrating lymphocytes might overcome resistance to anti-PD-1/PD-L1 therapies

  • Combination approaches targeting both checkpoint receptors and SHP-1 phosphorylation represent a promising strategy

• CAR-T cell optimization:

  • Engineering CAR-T cells with modified SHP-1 Tyr536 phosphorylation dynamics could enhance their persistence and activity

  • Reducing inhibitory signaling through controlled manipulation of SHP-1 function may improve anti-tumor responses

  • Monitoring Tyr536 phosphorylation could serve as a biomarker for CAR-T exhaustion states

• Autoimmune disease intervention:

  • Enhancing SHP-1 activity through targeted increases in Tyr536 phosphorylation could dampen pathological immune activation

  • Small molecules that promote or stabilize this phosphorylation represent potential therapeutic agents

  • Cell-type specific delivery of such modulators could provide precision in targeting affected immune populations

• Therapeutic antibody development:

  • Monoclonal antibodies that modulate SHP-1 conformation upon binding could influence Tyr536 phosphorylation

  • Such antibodies might serve as novel immunomodulatory agents

  • Structure-guided design based on the Tyr536 region could yield selective modulators of SHP-1 function

• Companion diagnostics:

  • Using the Phospho-PTPN6 (Tyr536) Antibody to assess patient samples could help predict response to immunotherapies

  • Stratification of patients based on baseline SHP-1 phosphorylation levels might guide treatment selection

  • Monitoring changes in phosphorylation during treatment could provide early indicators of response

These approaches highlight the translational potential of basic research on PTPN6/SHP-1 phosphorylation dynamics in improving existing immunotherapies and developing novel therapeutic strategies.