Recombinant Mouse Probable G-protein coupled receptor 162 (Gpr162)

What is the structural classification of Mouse Gpr162?

Mouse Gpr162 is classified as a Class A (Rhodopsin) Orphan receptor within the G protein-coupled receptor (GPCR) superfamily. Like other GPCRs, it contains seven transmembrane domains and functions by transducing extracellular signals through heterotrimeric G proteins. The receptor's structure includes distinct N-terminal, transmembrane, extracellular loop, intracellular loop, and C-terminal regions that are critical for its function. The complete amino acid sequence reveals the specific arrangement of these domains, providing important structural information for experimental design and data interpretation .

What expression systems are available for producing Recombinant Mouse Gpr162?

Recombinant Mouse Gpr162 can be produced using multiple expression systems, each with distinct advantages depending on research requirements. Available systems include in vitro E. coli expression systems (producing full-length protein), as well as partial protein expression in yeast, baculovirus, mammalian cell, and in vivo biotinylation in E. coli. The E. coli expression system (product code CSB-CF662378MO) typically offers high yield and cost-effectiveness, while mammalian expression systems may provide more native post-translational modifications. Selection of the appropriate expression system should be determined by the specific experimental requirements, including protein purity needs, functional assays planned, and structural studies .

What are the key considerations when designing experiments with Recombinant Mouse Gpr162?

When designing experiments with Recombinant Mouse Gpr162, researchers should consider several critical factors. First, as an orphan GPCR, Gpr162 lacks identified endogenous ligands, making functional characterization more challenging than with ligand-identified receptors. Second, the expression system choice significantly impacts protein quality – E. coli-expressed protein may lack post-translational modifications required for certain functional studies, while mammalian-expressed protein more closely mimics native conditions. Third, researchers must determine whether full-length or partial protein constructs are more suitable for their specific experimental goals. Finally, appropriate controls should be implemented, including vector-only controls for overexpression studies and validation with multiple antibodies for protein detection, as GPCRs can be difficult to study due to their hydrophobic transmembrane domains .

How can homology modeling be utilized to study Mouse Gpr162 structure and function?

Homology modeling represents a powerful approach for studying the structure and function of Mouse Gpr162, particularly given the challenges of direct crystallographic analysis of GPCRs. This methodology involves using solved GPCR structures as templates to generate computational models of Gpr162's three-dimensional structure. The process begins with sequence alignment between Gpr162 and crystallized Class A GPCRs, followed by model construction and refinement using molecular dynamics simulations. These simulations can reveal structural information not provided by static crystallographic data and help model flexible loop regions that are typically difficult to predict. The resulting structural models can then be used for virtual ligand screening to identify potential binding compounds, guide site-directed mutagenesis experiments, and predict protein-protein interactions. Advances in using multiple templates to build models have significantly improved the quality of GPCR homology models in recent years, making this approach increasingly valuable for orphan receptors like Gpr162 .

What methodologies are recommended for studying Gpr162's role in DNA damage response pathways?

To investigate Gpr162's role in DNA damage response pathways, researchers should implement a multi-faceted experimental approach. RNA transcriptomics sequencing of Gpr162-overexpressing versus control cells provides a comprehensive view of differentially expressed genes, followed by Gene Set Enrichment Analysis (GSEA) to identify enriched pathways. For functional validation, clone formation assays following irradiation at multiple time points can assess the impact of Gpr162 on DNA damage sensitivity. Researchers should also consider direct measurement of DNA damage markers (γH2AX foci, comet assays) in cells with modified Gpr162 expression. Mechanistically, investigation of the STING-dependent pathway through protein-protein interaction studies (co-immunoprecipitation, proximity ligation assays) and phosphorylation analysis of key pathway components can elucidate how Gpr162 regulates DNA damage response. Finally, CRISPR-Cas9 gene editing to create Gpr162 knockout models provides a definitive system for assessing its physiological role in DNA damage repair mechanisms .

What are the recommended approaches for identifying potential signaling pathways regulated by Gpr162?

For identifying signaling pathways regulated by orphan receptors like Gpr162, researchers should implement a systematic, multi-platform approach. Begin with transcriptomic analysis comparing Gpr162-overexpressing and control cells to identify differentially expressed genes, followed by pathway enrichment analysis using tools like KEGG or Gene Ontology. To investigate G-protein coupling specificity, employ BRET (Bioluminescence Resonance Energy Transfer) or FRET (Fluorescence Resonance Energy Transfer) assays measuring interactions between Gpr162 and different G-protein subtypes. Second messenger assays measuring cAMP, calcium flux, or IP3 levels in response to Gpr162 modulation can further characterize downstream signaling. Pharmacological approaches using specific pathway inhibitors in combination with Gpr162 overexpression or knockdown models help validate key pathway components. Protein-protein interaction studies using proximity-dependent biotin identification (BioID) or immunoprecipitation coupled with mass spectrometry can identify novel Gpr162 interacting partners. Finally, phenotypic screens in cellular models with altered Gpr162 expression can connect molecular pathways to functional outcomes .

How does Gpr162 overexpression affect cellular response to DNA damage?

Gpr162 overexpression significantly enhances cellular sensitivity to DNA damage through multiple mechanisms. Transcriptomic analysis of Gpr162-overexpressing cells reveals 875 differentially expressed genes compared to control cells, with Gene Set Enrichment Analysis demonstrating significant enrichment in DNA damage response, UV-C response, and bubble DNA binding pathways. Functionally, clone formation assays following irradiation show that Gpr162 overexpression substantially reduces cell proliferation after DNA damage, indicating increased sensitivity to genotoxic stress. This sensitivity appears to be mediated through a STING-dependent DNA damage pathway, suggesting Gpr162 may act as a sensor or regulator of genomic integrity. The mechanism likely involves activation of downstream effectors in the DNA damage response pathway, potentially including ATM/ATR signaling cascades and DNA repair machinery components. These findings suggest that Gpr162 expression levels could be an important determinant of cellular responses to genotoxic therapies, with potential implications for cancer treatment strategies targeting cells with DNA repair deficiencies .

What challenges might researchers encounter when studying orphan GPCRs like Gpr162?

Researchers studying orphan GPCRs like Gpr162 face several significant challenges that require specialized approaches. The primary obstacle is the absence of identified endogenous ligands, which complicates functional characterization and pharmacological manipulation. Without known natural ligands, traditional ligand-binding assays and structure-activity relationship studies become problematic. Additionally, many orphan GPCRs, including Gpr162, exhibit relatively low expression levels in native tissues, necessitating sensitive detection methods and careful control experiments. The high hydrophobicity of transmembrane domains creates technical difficulties in protein expression, purification, and structural studies, often resulting in protein aggregation or misfolding when expressed recombinantly. Furthermore, discriminating between constitutive (ligand-independent) activity and ligand-dependent signaling becomes particularly challenging. To overcome these obstacles, researchers should consider employing a combination of homology modeling, computational screening approaches, unbiased functional genomics, and reverse pharmacology techniques where synthetic compounds are screened for activity at the orphan receptor .

How can researchers determine if Gpr162 shows constitutive activity?

Determining constitutive activity in orphan receptors like Gpr162 requires a systematic approach involving multiple complementary techniques. First, researchers should establish baseline signaling in systems with varied Gpr162 expression levels by measuring canonical GPCR signaling outputs (cAMP, calcium flux, ERK phosphorylation) in cells overexpressing Gpr162 versus control cells. An elevated basal signaling state in Gpr162-expressing cells suggests constitutive activity. Inverse agonist screening, where compound libraries are tested for their ability to reduce this elevated basal activity, provides pharmacological evidence of constitutive signaling. Mutagenesis studies targeting conserved GPCR activation motifs (DRY motif, NPxxY motif) can identify residues critical for maintaining active receptor conformations, while BRET-based conformational sensors measuring distance changes between receptor domains can detect spontaneous adoption of active conformations. Additionally, analyzing the effects of Gpr162 expression on downstream transcriptional programs in the absence of stimulus provides functional evidence of ligand-independent activity. Finally, computational approaches using molecular dynamics simulations of homology models can predict conformational flexibility and potential constitutively active states .

What techniques are available for identifying potential ligands for orphan receptors like Gpr162?

Multiple complementary approaches can be employed to identify potential ligands for orphan receptors like Gpr162. High-throughput screening of compound libraries using functional assays (cAMP, calcium flux, β-arrestin recruitment) can identify synthetic molecules activating or inhibiting Gpr162 signaling. Computational approaches utilizing homology models in virtual ligand screening can predict binding compounds based on receptor structure, while metabolomics-guided biochemical fractionation of tissue extracts can isolate potential endogenous ligands. Reverse pharmacology approaches, starting with synthetic compounds showing activity and working backward to identify structurally similar endogenous molecules, have proven successful for other orphan GPCRs. Phenotypic screening in cellular or organism models with Gpr162 modulation can identify conditions where receptor function is essential, potentially pointing toward contexts where endogenous ligands operate. Finally, proximity-based labeling approaches like APEX or BioID can identify molecules interacting with the Gpr162 binding pocket in living cells. The most robust identification strategy typically combines multiple approaches, validating hits through orthogonal methods to confirm specific receptor activation .

What are the optimal experimental designs for studying the functional interaction between Gpr162 and the STING pathway?

To comprehensively investigate the functional interaction between Gpr162 and the STING pathway, researchers should implement a multi-faceted experimental design. Begin with co-immunoprecipitation and proximity ligation assays to determine if Gpr162 directly interacts with STING or upstream regulators. For pathway activation studies, measure canonical STING pathway outputs (phosphorylation of TBK1, IRF3, and production of type I interferons) in cellular models with modulated Gpr162 expression, with and without DNA damage induction. Perform epistasis experiments using STING inhibitors or STING knockout models in combination with Gpr162 overexpression to determine if Gpr162's effects on DNA damage sensitivity are STING-dependent. Conduct live-cell imaging using fluorescently tagged Gpr162 and STING to track potential co-localization and trafficking following DNA damage. For mechanistic studies, investigate whether Gpr162 influences cytosolic DNA sensing or cGAS activation using cGAMP production assays, and determine if Gpr162 affects STING dimerization, ubiquitination, or palmitoylation – critical post-translational modifications for STING activation. Finally, employ ChIP-seq to identify IRF3 binding sites following Gpr162-mediated STING activation to characterize the transcriptional program regulated by this pathway .

How does Mouse Gpr162 compare structurally and functionally to Human GPR162?

Mouse Gpr162 and Human GPR162 show significant structural and functional conservation, reflecting their evolutionary importance. Sequence analysis reveals high homology, particularly within the seven transmembrane domains and intracellular regions involved in G-protein coupling. The amino acid sequence conservation is especially pronounced in the DRY motif (critical for G-protein activation) and other functional motifs typical of Class A GPCRs. Despite these similarities, species-specific differences exist in extracellular loop regions, potentially affecting ligand recognition and binding properties. Functionally, both receptors appear to be involved in DNA damage response pathways, suggesting conservation of this critical role across species. Available recombinant proteins for both species can be expressed in multiple systems, including E. coli, yeast, baculovirus, and mammalian cells, facilitating comparative studies. When designing translational research, these species-specific differences should be considered, particularly when extrapolating results from mouse models to human applications. Antibodies with cross-reactivity between species (such as CSB-PA009775GA01HU, which reacts with both human and mouse Gpr162) are particularly valuable tools for comparative studies across species .

What expression patterns of Gpr162 are observed across different mouse tissues and disease models?

While comprehensive tissue expression data for Gpr162 is still emerging, current research indicates distinctive expression patterns across mouse tissues and disease models. RNA-seq data from various tissues suggests relatively high expression in neuronal and neuroendocrine tissues, with moderate expression in immune cells and variable expression across other tissue types. In disease models, particularly those involving DNA damage response pathways, Gpr162 expression appears to be dynamically regulated. The receptor's involvement in DNA damage response pathways suggests potential roles in cancer models, particularly those treated with genotoxic agents. Transcriptomic analysis of Gpr162-overexpressing cells reveals regulation of 875 differentially expressed genes compared to control cells, with significant enrichment in pathways related to DNA damage, UV-C response, and DNA binding. This widespread transcriptional impact indicates Gpr162 may function as a signaling hub in multiple cellular processes. For researchers studying specific disease models, careful quantification of endogenous Gpr162 expression is recommended to determine the physiological relevance of the receptor in the system under investigation .

What are the recommended controls and validation steps when studying Gpr162 function through overexpression or knockdown approaches?

Robust experimental design for Gpr162 functional studies requires comprehensive controls and validation steps. For overexpression studies, researchers should implement multiple control conditions, including empty vector controls, overexpression of an unrelated GPCR, and different expression levels of Gpr162 to establish dose-dependent effects. Expression validation should combine protein quantification (Western blot, flow cytometry) with subcellular localization confirmation (immunofluorescence) to verify proper membrane trafficking. Functional validation through multiple readouts (cAMP levels, calcium flux, ERK phosphorylation) helps establish which signaling pathways are activated. For knockdown or knockout approaches, researchers should employ multiple siRNAs or guide RNAs targeting different regions of Gpr162 to minimize off-target effects, alongside scrambled controls. Rescue experiments, where wild-type Gpr162 is reintroduced into knockout models, provide strong evidence that observed phenotypes are specifically due to Gpr162 loss. For studies focusing on DNA damage response, appropriate positive controls (irradiation, genotoxic agents) and time-course experiments are essential. Finally, researchers should validate key findings across multiple cell types or primary cells to ensure the observed effects are not cell-line specific artifacts .

Available Recombinant Mouse Gpr162 Products and Expression Systems

The following table summarizes currently available recombinant Mouse Gpr162 products and their corresponding expression systems:

Each expression system offers distinct advantages depending on experimental requirements. E. coli systems typically provide high yield but may lack post-translational modifications, while mammalian cell systems often provide more native protein configurations .

Differentially Expressed Pathways in Gpr162 Overexpression Models

RNA transcriptomics sequencing on Gpr162-overexpressed versus control cells revealed significant pathway enrichment as analyzed by Gene Set Enrichment Analysis (GSEA):

Transmembrane Domain Organization of Mouse Gpr162

The complete sequence analysis of Mouse Gpr162 reveals the following transmembrane domain organization: