Recombinant Mouse Taste receptor type 2 member 129 (Tas2r129)
Description
Gene and Protein Identification
Tas2r129, known by several synonyms including mGR29, mt2r60, T2R29, and Tas2r29, is a gene encoding a bitter taste receptor in mice . The gene has been identified with the gene ID 387354 in the mouse genome . The protein product of this gene is officially named taste receptor type 2 member 129 and is cataloged in the UniProt database with the identifier Q7M709 . As a member of the taste receptor type 2 (T2R) family, Tas2r129 belongs to the larger G protein-coupled receptor (GPCR) superfamily, characterized by a seven-transmembrane domain structure and G protein coupling for signal transduction .
Molecular Characterization
The mouse Tas2r129 protein consists of 320 amino acids in its full-length form, with the complete sequence available from recombinant protein resources . The protein's membrane-spanning nature makes it challenging to study in its native state, which has led to the development of various recombinant expression systems to facilitate research. These recombinant approaches allow for the production of the protein with various fusion tags, enabling structural studies, functional assays, and expression analyses that would otherwise be difficult with naturally sourced protein.
Three-Dimensional Structure
While the search results do not provide specific information on the three-dimensional structure of Tas2r129, as a member of the GPCR family, it likely adopts the characteristic seven-helical bundle arrangement typical of these receptors. The transmembrane domains form α-helices that span the cell membrane, with the ligand-binding pocket typically formed within the helical bundle. The structural features of Tas2r129 are critical for its function in recognizing bitter compounds and coupling to downstream signaling proteins.
Expression Systems
Recombinant Tas2r129 can be produced in multiple expression systems, each with distinct advantages for different research applications. According to the search results, the following expression platforms are used for Tas2r129 production:
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Bacterial expression (E. coli) - Provides high protein yields but may lack mammalian post-translational modifications
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Mammalian cell expression (including HEK293) - Offers more authentic protein processing and folding
The choice of expression system depends on the intended use of the recombinant protein. For functional studies requiring proper folding and post-translational modifications, mammalian expression systems are preferred, while bacterial systems may be suitable for applications where these features are less critical.
Fusion Tags and Protein Variants
Various fusion tags can be incorporated into recombinant Tas2r129 to facilitate detection, purification, and functional studies. The search results indicate several available tagged variants:
These tagged variants provide researchers with flexibility in experimental design, allowing for various approaches to studying Tas2r129 structure, localization, and function.
Functional and Binding Studies
Recombinant Tas2r129 proteins serve as valuable tools for investigating bitter taste transduction mechanisms. These applications include:
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Ligand binding assays to identify bitter compounds that activate the receptor
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Functional assays to characterize signaling pathways activated upon receptor stimulation
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Structure-function relationship studies to understand the molecular basis of bitter compound recognition
The availability of different tagged variants facilitates various experimental approaches. For instance, His-tagged proteins are useful for purification and binding studies, while fluorescently tagged variants allow for visualization of receptor localization and trafficking.
Gene Expression Modulation
Tools for modulating Tas2r129 expression are commercially available for functional studies. Specifically, shRNA constructs for Tas2r129 knockdown are offered in retroviral vectors, comprising 4 unique 29mer shRNA constructs along with a non-effective scrambled shRNA control . These tools enable researchers to:
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Investigate the physiological consequences of Tas2r129 downregulation
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Study the specificity of bitter compounds in activating Tas2r129-dependent signaling
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Examine potential compensatory mechanisms by other taste receptors
Such gene expression modulation approaches complement functional studies with recombinant proteins to provide a more comprehensive understanding of Tas2r129 biology.
Expression Profiling
Expression profiling of Tas2r129 across different tissues provides insights into its potential functions beyond taste perception. According to the search results, comprehensive expression profiling of Tas2r genes, including Tas2r129, has been conducted along the mouse gastrointestinal tract, revealing complex expression patterns . Additionally, Tas2r129 expression has been investigated in bladder tissues using specific probes (Mm03014501_s1) , suggesting potential sensory functions in this organ.
These expression studies typically employ quantitative RT-PCR techniques to measure gene expression levels, often using commercial probes designed specifically for Tas2r129 and other taste receptors.
Role in Taste Transduction
As a type 2 taste receptor, Tas2r129 plays a crucial role in the detection of bitter compounds. According to the search results, Tas2r129 is involved in the taste transduction pathway, functioning as a G-protein coupled receptor . Upon activation by bitter compounds, these receptors trigger a signaling cascade that involves:
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Coupling to G proteins
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Activation of downstream effectors such as phospholipase C beta 2 (PLCB2)
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Release of calcium from intracellular stores
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Depolarization of taste receptor cells
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Neurotransmitter release and signal transmission
Other proteins involved in this pathway include GNG13, PLCB2, PRKACB, and several other TAS2R family members .
Extraoral Functions
Beyond its role in taste perception, Tas2r129 may have important functions in tissues outside the oral cavity. The expression of Tas2r genes, including Tas2r129, in the gastrointestinal tract suggests potential roles in:
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Chemosensing in the digestive system
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Regulation of digestive processes
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Monitoring of ingested compounds
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Immune response modulation
Research has revealed that related taste receptors, such as Tas2r131, are expressed in a subset of intestinal Paneth cells , indicating specialized functions for these receptors in specific cell populations. The presence of Tas2r129 in bladder tissues further suggests broader sensory functions beyond traditional taste perception.
Expression Studies in Multiple Tissues
Recent research has focused on characterizing the expression of Tas2r genes, including Tas2r129, in various tissues beyond the oral cavity. A comprehensive expression profiling study examined all 35 mouse Tas2r genes in gastrointestinal tract tissues, revealing complex expression patterns that suggest specialized functions in different regions of the digestive system .
The specific expression of a related receptor, Tas2r131, in intestinal Paneth cells points to potential roles in immune function or chemosensing within the gut. Similar detailed studies of Tas2r129 expression at the cellular level would provide valuable insights into its specific functions in different tissues.
Pathway Analysis and Interacting Partners
Tas2r129 functions within the broader taste transduction pathway, interacting with various signaling proteins. According to the search results, this pathway includes several other proteins such as GNG13, PLCB2, and multiple TAS2R family members . Understanding the specific interactions between Tas2r129 and these pathway components is crucial for elucidating its signaling mechanisms and physiological functions.
Future research directions may include more detailed characterization of Tas2r129's interaction partners, signaling pathways, and potential cross-talk with other cellular processes. Such studies would enhance our understanding of bitter taste perception and the broader roles of taste receptors in health and disease.
Product Specs
Note: We will prioritize shipping the format currently in stock. However, if you have specific format requirements, please indicate them in your order, and we will fulfill them accordingly.
Note: All our proteins are shipped with standard blue ice packs by default. If you require dry ice shipping, please inform us in advance, as additional fees will apply.
Generally, the shelf life of liquid form is 6 months at -20°C/-80°C. The shelf life of lyophilized form is 12 months at -20°C/-80°C.
Target Background
Q&A
What is Taste Receptor Type 2 Member 129 (Tas2r129) and how does it relate to other bitter taste receptors?
Taste receptor type 2 member 129 (Tas2r129) belongs to the taste receptor type 2 (Tas2r) family, which functions as G protein-coupled receptors that detect bitter compounds. In the broader context of bitter taste receptors, these proteins are expressed not only in taste buds but also in extraoral tissues, including urinary bladder detrusor smooth muscle (DSM) . While Tas2r129 specifically is not among the most abundantly expressed taste receptors in mouse DSM, related family members such as Tas2r114, Tas2r117, Tas2r130, Tas2r138, and Tas2r144 show significant expression in these tissues . The receptor is also known by synonyms including T2R129, mT2R60, T2r60, and in some literature as T2R29 or mGR29 .
What expression patterns have been observed for Tas2r family members in mouse tissues?
Research has demonstrated varied expression patterns for Tas2r genes in mouse tissues. In detrusor smooth muscle specifically, RT-qPCR analysis has revealed that among 35 mouse Tas2r genes, only Tas2r114, Tas2r117, Tas2r130, Tas2r138, and Tas2r144 show significant expression . Of these, Tas2r114 exhibits expression levels comparable to the reference gene Gapdh, while fourteen other Tas2r genes show very low expression, and sixteen Tas2r genes were not detected at all . These expression profiles provide important context for understanding where and how Tas2r129 might function in comparison to other family members.
| Mouse Tas2r Expression in DSM | Expression Level |
|---|---|
| Tas2r114 | Similar to Gapdh (high) |
| Tas2r117, Tas2r130, Tas2r138, Tas2r144 | Significant |
| 14 other Tas2r genes | Very low |
| 16 Tas2r genes (including others) | Not detected |
How should researchers design experiments to study Tas2r129 function in mouse tissues?
When designing experiments to study Tas2r129 function, researchers should follow systematic experimental design principles. First, clearly define your independent variable (e.g., Tas2r129 activation by a specific agonist) and dependent variable (e.g., muscle relaxation or intracellular signaling) . Formulate a specific, testable hypothesis about how Tas2r129 activation affects your system of interest. Design treatments that specifically manipulate Tas2r129 activation while controlling for potential confounding variables .
For tissue-specific expression studies, consider:
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Obtaining appropriate tissue samples with proper controls
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Using RT-qPCR with validated primers specific to Tas2r129
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Including reference genes (like Gapdh) for normalization
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Comparing expression across multiple tissues to establish tissue specificity
For functional studies, pharmacological approaches using known bitter tastants can help establish receptor activity patterns, as demonstrated with compounds like chloroquine (CLQ), quinine, and denatonium in mouse DSM studies .
What are the optimal storage and handling conditions for recombinant Tas2r129 protein?
Recombinant Mouse Taste receptor type 2 member 129 (Tas2r129) should be stored at -20°C for general storage and at -80°C for long-term preservation . For working solutions, store aliquots at 4°C for up to one week . Avoid repeated freezing and thawing cycles as this may compromise protein integrity and activity . The protein is typically supplied as a liquid containing glycerol with >90% purity . When designing experiments, consider the following handling guidelines:
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Thaw aliquots on ice when removing from frozen storage
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Prepare working dilutions immediately before use
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Maintain appropriate temperature conditions during experimental procedures
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Document all freeze-thaw cycles and storage durations for reproducibility
How can researchers effectively measure Tas2r129 activation in experimental settings?
Measuring Tas2r129 activation requires appropriate functional assays. Based on methodologies applied to other Tas2r family members, researchers could employ:
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Tissue-level functional assays: For tissues expressing Tas2r129, measure physiological responses following exposure to potential agonists. For example, in smooth muscle tissues, monitor tension changes using an organ bath system, similar to methods used for studying other Tas2r receptors in DSM .
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Cellular calcium imaging: Since bitter taste receptors typically signal through calcium mobilization, measuring intracellular calcium changes in cells expressing Tas2r129 can provide direct evidence of receptor activation.
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Receptor internalization assays: Tracking receptor trafficking following exposure to potential ligands can indicate activation events.
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Comparative pharmacology: Test a panel of known bitter compounds and analyze response patterns, as demonstrated with chloroquine, quinine and denatonium in mouse DSM studies .
How do Tas2r receptors contribute to urinary bladder function and what implications might this have for Tas2r129 research?
Tas2r receptors play significant roles in urinary bladder function, particularly in detrusor smooth muscle (DSM). Activation of these receptors induces relaxation of both human and mouse DSM, with potential therapeutic implications for overactive bladder (OAB) . Pharmacological studies with bitter tastants such as chloroquine, quinine, and denatonium demonstrate concentration-dependent relaxation of mouse DSM strips pre-contracted with carbachol .
In a mouse model of partial bladder outlet obstruction (PBOO), chloroquine treatment significantly suppressed the bladder weight increase and muscle thickness changes normally observed in PBOO, suggesting therapeutic potential . This establishes a framework for investigating whether Tas2r129 specifically might contribute to similar physiological mechanisms.
Interestingly, species differences exist in Tas2r-mediated responses. For instance, mouse DSM shows a transient contraction before relaxation upon bitter tastant application, while human DSM does not exhibit this biphasic response . These differences suggest that "TAS2Rs and their downstream signaling pathways might be varied among species" , which researchers studying Tas2r129 should consider when translating findings between species.
What analytical approaches should researchers use to interpret Tas2r129 experimental data?
When analyzing data from Tas2r129 experiments, researchers should employ rigorous statistical methods appropriate for the experimental design. For expression studies using RT-qPCR, consider:
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Data normalization: Normalize Tas2r129 expression against stable reference genes like Gapdh .
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Between-group comparisons: Use appropriate statistical tests based on data distribution (parametric or non-parametric).
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Dose-response relationships: When testing receptor activation with various concentrations of ligands, fit data to appropriate pharmacological models to determine EC50/IC50 values.
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Data visualization: Present expression data in context, showing relative levels compared to other Tas2r family members, as done in studies of DSM where expression profiles revealed distinct patterns among different Tas2r genes .
For functional assays measuring physiological responses like muscle relaxation:
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Calculate percentage relaxation relative to pre-contraction
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Analyze concentration-dependence using regression models
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Compare pharmacological profiles across different tissues or conditions
How can researchers address common challenges in Tas2r129 expression studies?
Researchers studying Tas2r129 expression may encounter several technical challenges. To address these effectively:
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Low expression levels: If Tas2r129 shows low expression, employ more sensitive detection methods such as digital PCR or use enrichment techniques to isolate cells likely to express the receptor.
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Primer specificity: Given the sequence similarity among Tas2r family members, validate primer specificity through sequencing of amplicons, especially when expression patterns differ from published data.
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Reference gene selection: The choice of reference genes is critical. While Gapdh has been used for normalizing Tas2r expression in DSM studies , validate multiple reference genes for stability in your specific experimental conditions.
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Tissue heterogeneity: When working with complex tissues, consider single-cell approaches or cell sorting to identify specific cell populations expressing Tas2r129.
If experimental results contradict published findings, systematically rule out technical issues before concluding biological differences exist between your experimental system and previous reports.
How do species differences affect interpretation of Tas2r receptor studies, and what implications might this have for Tas2r129?
Significant species differences exist in Tas2r receptor biology, which must be considered when designing and interpreting Tas2r129 studies. Research on DSM has demonstrated that "TAS2Rs and their downstream signaling pathways might be varied among species" . For example, bitter tastants induce a transient contraction before relaxation in mouse DSM, but this biphasic response is absent in human tissues .
The expression profiles of Tas2r genes also differ between human and mouse tissues. In human DSM, TAS2R7 and TAS2R8 are most abundantly expressed, while in mouse DSM, Tas2r114 shows the highest expression among detected Tas2r genes . These differences highlight the importance of:
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Using appropriate animal models for specific research questions
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Exercising caution when extrapolating findings across species
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Validating key findings in human tissues when pursuing translational applications
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Considering evolutionary and functional differences in receptor repertoires
What are the potential therapeutic applications of research on Tas2r129 and related receptors?
Research on Tas2r family members has revealed potential therapeutic applications that might extend to Tas2r129. Studies demonstrate that Tas2r activation relaxes detrusor smooth muscle (DSM) in both humans and mice, suggesting therapeutic potential for overactive bladder (OAB) . In a mouse model of OAB induced by partial bladder outlet obstruction (PBOO), treatment with the bitter tastant chloroquine significantly reduced bladder weight increases and muscle thickening typically observed in this condition .
The therapeutic potential extends beyond simply understanding receptor function, as Tas2r activation appears to specifically suppress stimulus-induced contractions rather than affecting baseline muscle tone . This selective action suggests that targeted activation of these receptors might provide therapeutic benefits with potentially fewer side effects than current treatments.
When considering translational applications of Tas2r129 research specifically, investigators should:
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Establish the expression profile of Tas2r129 in relevant tissues
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Identify specific agonists with selectivity for Tas2r129
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Determine how Tas2r129 activation influences physiological processes in target tissues
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Evaluate potential off-target effects of receptor modulation
How should researchers approach comparative studies between mouse Tas2r129 and human TAS2R orthologs?
When conducting comparative studies between mouse Tas2r129 and potential human orthologs, researchers should:
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Perform sequence alignment and phylogenetic analyses to identify the closest human orthologs, recognizing that one-to-one orthology may not exist due to evolutionary divergence in bitter taste receptor repertoires.
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Compare expression patterns across species, as expression profiles of Tas2r genes differ between humans and mice. For example, in DSM, humans predominantly express TAS2R7 and TAS2R8, while mice show highest expression of Tas2r114 .
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Conduct functional comparisons using identical experimental protocols, as response patterns may differ between species even for related receptors. Studies on DSM have shown species-specific response patterns, with mouse tissues exhibiting transient contraction before relaxation, a phenomenon not observed in human tissues .
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Use experimental designs that account for species differences in downstream signaling pathways, as these may significantly influence physiological responses even when receptor activation is similar.
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Consider human-specific polymorphisms when selecting human cell lines or tissues for comparative studies, as genetic variation in taste receptors can influence function.
