Recombinant Mouse Taste receptor type 2 member 110 (Tas2r110)

What is Tas2r110 and what are its key synonyms in the literature?

Tas2r110 (taste receptor, type 2, member 110) is a G-protein coupled receptor involved in bitter taste sensation in mice. In scientific literature, this receptor is also known by several synonyms including T2R10, mt2r57, and Tas2r10 . When searching literature databases or ordering recombinant proteins, researchers should be aware of these alternative designations to ensure comprehensive coverage of relevant publications and resources.

What are the primary molecular functions of Tas2r110?

Tas2r110 serves several biochemical functions, with its primary role being G-protein coupled receptor activity. It also functions as a signal transducer, participating in taste transduction pathways. Based on functional characterization studies, Tas2r110 demonstrates molecular activities similar to other taste receptors in the type 2 family, primarily detecting bitter compounds and initiating signal transduction cascades that ultimately lead to taste perception . The receptor's activity is typically studied using calcium mobilization assays in heterologous expression systems, which can detect receptor activation upon ligand binding.

Which biological pathways involve Tas2r110?

Tas2r110 primarily participates in the taste transduction pathway. Within this pathway, it interacts with several other proteins including TAS2R109, GNB1, TRPM5, PLCB2, GNG13, TAS2R13, and others . The taste transduction pathway involves a cascade of molecular events following bitter compound binding to the receptor, ultimately leading to cellular depolarization and signal transmission to the brain. Understanding these pathway interactions is crucial for interpreting experimental results when studying Tas2r110 function in various contexts.

What expression systems are commonly used for producing recombinant Tas2r110?

Several expression systems are utilized for producing recombinant Tas2r110 protein for research purposes:

For functional studies requiring properly folded and post-translationally modified protein, mammalian expression systems (particularly HEK293 cells) are preferred due to their ability to correctly process G-protein coupled receptors . E. coli systems may be suitable for producing protein fragments for structural studies or antibody production.

How is Tas2r110, among other taste receptors, expressed in mouse tissues?

Expression of Tas2r110 has been studied using quantitative RT-PCR and in situ hybridization techniques. Research indicates varying expression levels across different taste receptor subtypes, with some receptors like Tas2r118 showing stronger expression than others . The correlation between qRT-PCR results and in situ hybridization staining intensity suggests that these methods provide consistent measurement of receptor expression. Beyond taste tissues, some Tas2r receptors (such as Tas2r114) show expression in non-taste tissues like testis, indicating potential extraoral functions .

What challenges exist in heterologous expression studies of Tas2r110?

Heterologous expression of Tas2r110 presents several challenges that researchers must address:

• Cell surface localization: While many Tas2r receptors show clear external localization of epitope tags added to the N-terminus when expressed in heterologous systems, some receptors may exhibit poor trafficking to the plasma membrane. Immunocytochemistry studies have shown that Tas2r110 can be detected at the cell surface in unpermeabilized cells , indicating successful trafficking.

• G-protein coupling: The choice of G-protein alpha subunit significantly affects signal detection sensitivity. Studies have demonstrated that using Gα16gust44 provides higher sensitivity than Gα15-based assays for detecting Tas2r105 activation . Similar considerations likely apply to Tas2r110 studies.

• Receptor polymorphisms: Strain-specific sequence variations may affect receptor function. Nelson et al. reported significant amino acid sequence differences in most Tas2r genes when comparing C57BL/6 and DBA/2J mouse strains . These sequence variations could potentially impact ligand response profiles, necessitating careful consideration of the mouse strain origin when studying receptor function.

How does the functional characterization of Tas2r110 compare with other mouse bitter taste receptors?

Comprehensive functional characterization of mouse Tas2r receptors has revealed significant diversity in their tuning breadth and agonist profiles:

• Tuning breadth: Mouse Tas2r receptors vary in the number of compounds they can detect, with some functioning as specialists (responding to <3% of test compounds) and others as generalists. For example, Tas2r105 functions as a generalist, recognizing >30% of tested bitter compounds, while other receptors show much narrower response profiles .

• Receptor specificity: Despite overlapping agonist profiles, each mouse Tas2r is activated by a unique subset of compounds. Eight Tas2r receptors have been found to have specific cognate agonists not detected by any other identified Tas2r .

• Efficacy and potency: Different agonists activate mouse Tas2r receptors with widely different efficacies and potencies, as illustrated by the varying maximal signal amplitudes, threshold concentrations, and EC50 values . This variability suggests that different receptors may be physiologically more important for detecting specific compounds at relevant concentrations.

What methodological approaches overcome challenges in deorphanizing Tas2r110?

Deorphanizing G-protein coupled receptors like Tas2r110 requires careful methodological considerations:

• G-protein selection: The choice of G-protein significantly impacts assay sensitivity. Research has shown that Gα16gust44 provides higher sensitivity than Gα15 for detecting bitter taste receptor activation . This enhanced sensitivity can be crucial for identifying low-efficacy activators.

• Expression verification: Confirming cell surface expression is essential before concluding that a receptor cannot be deorphanized. Immunocytochemistry of both permeabilized and unpermeabilized cells helps distinguish between expression and trafficking issues .

• Compound screening strategy: Using a diverse chemical library with compounds at multiple concentrations increases the likelihood of identifying receptor agonists. When initial screens fail, testing compound mixtures followed by deconvolution can sometimes identify activators that might be missed in individual compound screens.

• Signal detection optimization: Optimizing calcium indicator loading, fluorescence detection parameters, and data normalization procedures can improve the signal-to-noise ratio and facilitate detection of subtle activation responses.

What are the most reliable methods for measuring Tas2r110 expression in tissue samples?

Several complementary methods provide reliable measurement of Tas2r110 expression in tissue samples:

• Quantitative RT-PCR: This technique allows precise quantification of mRNA levels. Studies have shown good correlation between qRT-PCR results and other expression detection methods for taste receptors . For Tas2r110, qRT-PCR can provide relative expression levels compared to other taste receptors or reference genes.

• In situ hybridization: This technique visualizes the spatial distribution of Tas2r110 mRNA in tissue sections. Research has demonstrated good correlation between qRT-PCR expression levels and in situ hybridization signal intensity for multiple taste receptors . The advantage of this method is the ability to identify specific cell types expressing the receptor.

• Immunohistochemistry: Using antibodies against Tas2r110 or epitope-tagged versions of the receptor, this method can detect protein expression and localization. For receptors with low expression levels, signal amplification techniques may be necessary.

• Single-cell RNA sequencing: This emerging technique can provide comprehensive expression profiles at the single-cell level, allowing identification of cell populations expressing Tas2r110 along with co-expressed genes that may functionally interact with the receptor.