TAS1R2 Antibody

What is TAS1R2 and what are its key characteristics?

TAS1R2 (Taste Receptor Type 1 Member 2) is a G-protein coupled receptor that forms part of the sweet taste receptor complex. The protein has the following characteristics:

TAS1R2 forms a heterodimer with TAS1R3 to create a functional sweet taste receptor that recognizes diverse natural sugars (sucrose, fructose) and synthetic sweeteners . The receptor can bind to G proteins, and studies confirm that TAS1R1 and TAS1R2 activate Gαo and Gαi, affecting human sweet taste receptors and inhibiting adenylyl cyclases to decrease cyclic guanosine monophosphate (cGMP) levels in taste receptors .

Where is TAS1R2 expressed beyond taste receptor cells?

While TAS1R2 was originally identified in taste buds, research has revealed it is expressed in multiple tissues:

• Skeletal muscle (mouse and human myofibers)

• Mouse and human primary myocyte cultures

• Pancreas (human tissue)

Recent research has demonstrated that TAS1R2 functions as a plasma membrane glucose sensor in skeletal muscle that regulates muscle mass and fitness . This discovery represents a significant expansion of our understanding of TAS1R2 beyond its canonical role in taste perception.

What types of TAS1R2 antibodies are available for research?

Several validated antibodies targeting different epitopes of TAS1R2 are available:

When selecting an antibody, researchers should consider the specific application, species reactivity, and the epitope being targeted .

How can I validate the specificity of TAS1R2 antibodies?

Validating antibody specificity is critical due to reliability issues noted with some TAS1R2 antibodies . Recommended validation approaches include:

• Positive controls: Use tissue known to express TAS1R2 (tongue tissue from mouse/rat is recommended)

• Knockout validation: Compare signals between wild-type and TAS1R2 knockout models

• Reporter systems: Use TAS1R2 reporter mice to confirm expression patterns

• Molecular weight verification: Confirm the observed band is at the expected molecular weight (~100 kDa)

• Peptide competition: Pre-incubate the antibody with the immunizing peptide to confirm specific binding

Research has shown reliability issues with some TAS1R2 antibodies, which can be partially circumvented using reporter mice for expression validation .

What are the optimal conditions for Western blot detection of TAS1R2?

For optimal Western blot detection of TAS1R2:

• Sample preparation: Use RIPA buffer for tissue lysate preparation

• Protein loading: Load 35 μg of total protein per lane

• Antibody dilution:

  • For ab77346: Use 0.3 μg/mL

  • For 29344-1-AP: Use 1:500-1:2000 dilution

• Incubation time: Primary antibody incubation for 1 hour

• Detection method: Chemiluminescence is recommended

• Expected band size: ~100 kDa (slightly higher than the calculated 95 kDa)

When working with TAS1R2, human pancreas lysate serves as a good positive control for Western blot applications .

What is the recommended protocol for immunohistochemical detection of TAS1R2?

For immunohistochemical detection:

• Sample preparation: Use formalin-fixed, paraffin-embedded tissue sections

• Antibody selection: ab150495 has been validated for IHC-P applications

• Antibody concentration: Use at 9 μg/ml concentration

• Positive control tissue: Human taste receptor cells have been validated as a positive control

• Detection system: Standard secondary antibody detection systems are compatible

Optimize antigen retrieval methods for your specific tissue type, as these may vary depending on fixation conditions.

How can I optimize protein purification of TAS1R2 for functional studies?

Based on published purification strategies :

• Expression system: Use HEK293S-GnTI- cells transfected with FLAG-tagged hTAS1R2

• Induction: Combine tetracycline and sodium butyrate (NaBu) for optimal expression

• Screening: Use dot blot analysis with anti-FLAG M2 antibody to identify high-expressing clones

• Purification:

  • Immunoaffinity purification using anti-FLAG antibodies

  • Further purify using gel filtration chromatography

  • Monitor fractions by SDS-PAGE and Western blot

• Expected yield: ~2.2 μg/flask from this optimized protocol

• Verification: Confirm purified protein using Coomassie staining and Western blotting

This protocol yielded approximately 135 μg of purified hTAS1R2 protein from sixty T225 flasks in published research .

How does TAS1R2 function in skeletal muscle, and what techniques can investigate this role?

Recent research has revealed TAS1R2 functions as a plasma membrane glucose sensor in skeletal muscle, regulating muscle mass and fitness through the ERK2-PARP1-NAD signaling axis . To investigate this:

• Gene deletion models: Generate muscle-specific TAS1R2 knockout mice (mKO) to study phenotypic changes

• Reporter systems: Use TAS1R2 reporter mice to visualize expression in myofibers

• Functional assessments:

  • Measure grip strength for muscle function

  • Assess running endurance

  • Analyze myofiber cross-sectional area (CSA)

• Biochemical analysis:

  • Measure NAD levels

  • Assess protein poly(ADP)-ribosylation (PAR) as a PARP activity marker

  • Evaluate PGC1α acetylation status

  • Analyze mitochondrial protein content

Muscle-specific deletion of TAS1R2 in mice produced elevated NAD levels due to suppressed PARP1 activity, improved mitochondrial function, increased muscle mass and strength, and prolonged running endurance .

How can I investigate TAS1R2 polymorphisms and their functional significance?

To study TAS1R2 polymorphisms:

• SNP identification: Focus on major SNPs like TAS1R2-Ile191Val (rs35874116), which is a partial loss-of-function variant associated with lower sugar sensitivity

• Genotyping: Use standard genotyping methods to classify participants (e.g., Ile/Ile for conventional function vs. Val/_ for partial loss-of-function)

• Phenotypic correlation: Assess parameters including:

  • Glucose control (oral glucose tolerance test)

  • Body composition

  • Mitochondrial and aerobic capacity

  • Muscle strength

• Intervention studies: Compare responses to interventions (e.g., exercise training) between genotype groups

• Molecular mechanism: Investigate downstream signaling differences between variants

Research has shown that partial loss-of-function of TAS1R2 (rs35874116) in older, obese humans recapitulated the healthier muscle phenotype displayed by TAS1R2 knockout mice in response to exercise training .

What methodological considerations are important when studying TAS1R2-mediated signaling pathways?

When investigating TAS1R2 signaling pathways:

• Receptor activation: Use known ligands such as natural sugars (sucrose, fructose) or synthetic sweeteners

• Downstream signaling:

  • Monitor ERK2 activation (phosphorylation status)

  • Assess PARP1 activity through PAR levels

  • Measure NAD levels using appropriate assays

  • Evaluate SIRT1 activity through deacetylation of targets like PGC1α

  • Monitor AMPK activation status

• Pathway validation: Use pharmacological inhibitors like PARP1/2 inhibitor PJ34 to confirm pathway components

• Glucose dependence: Design experiments to test receptor response across physiological glucose concentrations

• Tissue-specific effects: Compare signaling in different tissues expressing TAS1R2

The TAS1R2-mediated signaling cascade involves activation of ERK2, which then activates PARP1 through specific phosphorylation. This novel signaling pathway appears to respond to ambient glucose fluctuations through the activation of the STR-PARP1 axis .

How do I design experiments to investigate the interaction between TAS1R2 and obesity or aging?

For studies on TAS1R2 in obesity or aging contexts:

• Animal models:

  • For obesity: Use genetic models (e.g., ob/ob mice) or diet-induced obesity

  • For aging: Compare young vs. aged (e.g., 27-month-old) mice

• Genetic manipulation: Create tissue-specific TAS1R2 knockouts in these models

• Outcome measures:

  • Body composition (fat mass, lean mass)

  • Muscle fiber cross-sectional area

  • Grip strength

  • Mitochondrial protein content

  • Running endurance

  • Cardiac function (to rule out confounding effects)

• Human translation: Design studies with human subjects carrying TAS1R2 variants in similar conditions

Research has shown that deletion of TAS1R2 in obese or aged mice ameliorated the decline in muscle mass and fitness arising from these conditions, suggesting inhibition of TAS1R2 signaling may be a therapeutic approach to preserve muscle mass and function .

What controls and validation steps are critical when publishing research using TAS1R2 antibodies?

Due to reported issues with TAS1R2 antibody reliability , comprehensive validation is essential:

• Multiple antibody approach: Use at least two different antibodies targeting different epitopes

• Genetic controls: Include TAS1R2 knockout tissues as negative controls

• Complementary techniques: Support antibody-based detection with mRNA analysis or reporter systems

• Blocking peptides: Demonstrate specificity using immunizing peptide competition

• Full antibody documentation: Report catalog numbers, dilutions, incubation conditions, and lot numbers

• Positive controls: Always include known positive control samples (e.g., tongue tissue)

• Expected molecular weight verification: Confirm band at ~100 kDa for Western blot applications

Including all these validation steps will significantly strengthen the reliability and reproducibility of research findings involving TAS1R2 antibodies.