GSTP2 Mouse
Description
Introduction and Definition
GSTP2 Mouse refers to the mouse homolog of the glutathione S-transferase pi-class 2 (Gstp2) enzyme. This enzyme belongs to the GST superfamily, which catalyzes the conjugation of reduced glutathione to electrophilic substrates, playing critical roles in detoxification, oxidative stress management, and cellular protection . In mice, Gstp2 is distinct from Gstp1, its closely related paralog, with differences in tissue expression, substrate specificity, and functional roles . Recombinant GSTP2 Mouse protein is commonly produced in Escherichia coli for research purposes, often with a His-tag for purification .
Liver Regeneration
GSTP2, in conjunction with GSTP1, regulates hepatocyte proliferation during liver regeneration. Key findings include:
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Expression Dynamics: Gstp1/p2 mRNA and protein levels peak 2–6 hours post-hepatectomy (PH) in periportal hepatocytes, declining thereafter .
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Signaling Pathways:
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Oxidative Stress: Depletion of GSTP1/2 exacerbates oxidative damage in regenerating livers .
Modulation of Allergic Responses
In murine asthma models, GSTP2 (and GSTP1) suppresses allergic inflammation:
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Eosinophilia and AHR: Gstp-null mice exhibit elevated blood/airway eosinophilia and airway hyperresponsiveness (AHR) .
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Mucus Production: Goblet cell hyperplasia and Ym1/2 (alternatively activated macrophage marker) expression are amplified in Gstp-deficient mice .
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Strain-Specific Expression: C57BL/6 mice predominantly express Gstp1, while BALB/c mice favor Gstp2. GSTP2’s lower enzymatic activity (vs. GSTP1) is attributed to amino acid substitutions (e.g., Pro12→Arg12 in Mus spretus) .
Detoxification and Toxicity Resistance
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PAH/PCB Toxicity: GSTp2 protects zebrafish embryos from polycyclic aromatic hydrocarbon (PAH)-induced cardiotoxicity but does not mitigate PCB-126 effects .
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Species-Specific Roles:
Genetic and Regulatory Insights
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Promoter Variations: Sequence divergence in Gstp2 promoters between M. musculus and M. spretus correlates with differential expression .
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Induction Patterns: Unlike GSTP1, GSTP2 expression is not induced by Nrf2, CAR, or PXR activators but is downregulated by PPARα ligands .
Recombinant Production and Biochemical Properties
Biochemical Stability:
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Storage: -20°C (long-term) or 4°C (short-term) in PBS/glycerol .
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Stability: Resists freeze-thaw cycles; maintain aliquoted stocks .
Table 1: GSTP2 vs. GSTP1 in Mice
Table 2: Key Studies on GSTP2 Function
Product Specs
Q&A
What is GSTP2 and how does it differ from other GST family members in mice?
GSTP2 (Glutathione S-transferase Pi 2) is one of two Pi-class GST genes in mice, alongside GSTP1. The GST superfamily in mammals contains over a dozen cytosolic genes divided among 7 classes (alpha, mu, omega, pi, sigma, theta, and zeta), plus additional soluble Kappa class and membrane-associated proteins (MAPEG) .
GSTP2 is specifically a Pi-class GST, which functions in Phase II detoxification using GSH conjugation. Unlike other GST family members that have clearly defined detoxification functions, GSTP2 in laboratory mice (Mus musculus) shows almost undetectable expression in liver and its product lacks activity against typical GST/GST-Pi substrates . This contrasts with Mus spretus (aboriginal mouse species), where the GSTP2 gene achieves relatively high expression levels .
Methodologically, researchers distinguish between GST family members through:
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Gene expression analysis (qRT-PCR)
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Substrate specificity assays
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Immunological techniques using isoform-specific antibodies
What are the functional characteristics of mouse GSTP2 protein?
Mouse GSTP2 protein is a single, non-glycosylated polypeptide chain containing 210 amino acids with a molecular mass of approximately 25.9kDa . The protein functions as a multifunctional enzyme involved in:
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Protection of cellular components against anti-cancer drugs
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Defense against peroxidative stress
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Potential role in neuronal protection (down-regulation induces increased oxidative damage in pyramidal cells of CA1 & CA3 regions and granular layer of dentate gyrus)
The functional capabilities of GSTP2 vary between mouse species. In laboratory mice (Mus musculus), GSTP2 product lacks activity against typical GST substrates, while in Mus spretus, a Pro(12) to Arg(12) substitution suggests the MsGstp2 product may be an active Pi-class GST .
How is GSTP2 expression regulated in different mouse species?
The regulation of GSTP2 expression shows remarkable species-specific differences:
In Mus musculus (laboratory mice):
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Expression is almost undetectable in liver tissue
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Has limited reactivity with typical GST substrates
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Shows minimal response to environmental pollutants
In Mus spretus (aboriginal mice):
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Achieves relatively high steady-state expression levels (~30 molecules/pg of total liver RNA in non-polluted areas)
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Expression significantly increases in response to environmental pollution
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Co-evolves expression patterns with GSTP1 in response to environmental challenges
This differential expression appears to be due to evolutionary divergence in the promoter regions, with high sequence divergence (2.8%) and differences in transcription factor binding sites (32.6%) between the two Gstp2 promoters . Experimental validation using luciferase reporter assays confirmed that these promoter sequence variations determine the species-specific differences in expression levels .
What are the optimal protocols for studying GSTP2 expression in mouse models?
For accurate quantification and characterization of GSTP2 expression in mouse models, researchers should employ a multi-method approach:
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Absolute real-time RT-PCR:
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Promoter sequence analysis:
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Protein detection techniques:
When comparing different mouse strains or species, it's crucial to maintain consistent tissue collection, storage, and processing protocols to minimize technical variance.
How can GSTP1/GSTP2 knockout mouse models be effectively utilized in toxicology studies?
GSTP1/GSTP2 knockout mouse models serve as valuable tools for toxicological investigations:
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Experimental design considerations:
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Use both homozygous knockouts and wild-type controls
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Include heterozygous animals to assess gene dosage effects
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Control for strain background effects through appropriate backcrossing
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Key applications:
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Methodological approach:
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Expose animals to graduated doses of xenobiotics
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Monitor physiological responses and survival rates
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Perform tissue-specific analysis of oxidative damage markers
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Measure GSH/GSSG ratios to assess glutathione homeostasis
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Data interpretation guidelines:
What techniques are most effective for differentiating between GSTP1 and GSTP2 functions in mouse experimental systems?
Distinguishing between the functions of these closely related isozymes requires specialized approaches:
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Isoform-specific gene silencing:
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Design siRNAs targeting unique regions of each transcript
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Validate knockdown specificity through qRT-PCR with isoform-specific primers
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Use CRISPR-Cas9 for selective gene inactivation
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Recombinant protein characterization:
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Isoform-specific antibody development:
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Generate antibodies against unique epitopes
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Validate antibody specificity through Western blotting of recombinant proteins
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Apply in immunohistochemistry to detect tissue-specific expression patterns
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Chimeric protein analysis:
How do environmental factors influence GSTP2 expression patterns in different mouse species, and what are the implications for xenobiotic metabolism research?
Environmental response differences between mouse species offer insights into adaptive detoxification mechanisms:
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Comparative expression analysis:
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M. spretus mice dwelling in industrial settlements show significantly higher transcript levels for both GST-P1 and GST-P2 compared to those from non-polluted areas
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This suggests coordinated regulation of Pi-class GSTs in response to environmental challenges
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Laboratory mice (M. musculus) lack this robust environmental response for GSTP2
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Experimental approaches to study environmental impacts:
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Field studies comparing mice from polluted vs. pristine environments
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Controlled laboratory exposure to specific pollutants with time-course analysis
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Cell culture models with reporter constructs containing species-specific promoters
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Mechanistic investigations:
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Epigenetic analysis of promoter methylation patterns
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Identification of environmentally-responsive transcription factors
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Chromatin immunoprecipitation to detect altered transcription factor binding
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Research implications:
What is the relationship between GSTP2 genetic variants and susceptibility to carcinogenesis in mouse models?
The link between GSTP2 genetic variation and cancer susceptibility represents an important research area:
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Current evidence:
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Mice with null mutations in both Gstp1 and Gstp2 exhibit increased susceptibility to DMBA and TPA-induced skin papillomas
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The specific contribution of GSTP2 (independent of GSTP1) remains incompletely characterized
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Species differences in GSTP2 activity correlate with differing resistance to environmental carcinogens
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Experimental approaches:
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Generate selective GSTP2 knockout models (while preserving GSTP1)
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Introduce specific variants (e.g., Pro12Arg) through knock-in techniques
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Perform carcinogen challenge studies with tissue-specific analysis
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Comparative carcinogenesis studies:
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Cross-species comparison between M. musculus and M. spretus
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Correlation of GSTP2 expression levels with tumor development rates
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Multi-tissue analysis to identify cancer type-specific effects
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Translational significance:
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Understanding whether GSTP2 differences contribute to species-specific cancer resistance
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Identification of potential biomarkers for carcinogen susceptibility
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Development of intervention strategies targeting GST pathways
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How does the functional divergence of GSTP2 between mouse species inform our understanding of detoxification system evolution?
The evolutionary divergence of GSTP2 provides insights into adaptation mechanisms:
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Evolutionary analysis findings:
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Molecular evolution research approaches:
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Phylogenetic analysis across multiple rodent species
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Positive selection analysis to identify adaptively evolving residues
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Reconstruction of ancestral sequences to trace functional changes
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Functional divergence characterization:
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Compare substrate specificities across species
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Identify species-specific protein-protein interactions
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Examine co-evolution patterns with environmental detoxification demands
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Theoretical implications:
What methodological approaches can resolve contradictory findings regarding GSTP2 function in different experimental systems?
Resolving contradictory results requires systematic methodological considerations:
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Sources of experimental discrepancies:
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Species differences (M. musculus vs. M. spretus) often not explicitly stated
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Strain background variations within laboratory mice
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Differential sensitivity of detection methods for low-expression genes
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Presence of contaminating proteins in purification procedures
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Standardization approaches:
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Detailed reporting of mouse genetic background
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Use of absolute quantification methods rather than relative expression
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Inclusion of positive and negative controls for enzymatic activity assays
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Multiple complementary approaches to verify key findings
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Technical solutions for challenging experiments:
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Single-cell analysis to detect heterogeneous expression
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Advanced mass spectrometry for protein identification and quantification
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In situ techniques to localize expression in specific cell types
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Computational modeling to predict functional consequences of sequence variations
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Reconciliation framework:
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Establish a clear distinction between species-specific findings
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Consider developmental and tissue-specific contexts
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Account for environmental influences on expression patterns
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Develop integrative models that incorporate multiple datasets
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Product Science Overview
Glutathione S-Transferases (GSTs) are a family of enzymes involved in the detoxification of endogenous and exogenous compounds. They catalyze the conjugation of the reduced form of glutathione (GSH) to xenobiotic substrates, facilitating their excretion from the body . Among the various classes of GSTs, the Pi class (GSTP) is particularly noteworthy due to its abundance and functional significance in mammalian cells .
GSTP is a homodimeric enzyme, meaning it consists of two identical subunits. Each subunit has a GSH-binding site and a substrate-binding site (H-site), which together facilitate the enzyme’s catalytic activity . The enzyme’s primary function is to detoxify harmful compounds by conjugating them with GSH, making them more water-soluble and easier to excrete .
In mice, the GSTP gene cluster includes multiple isoforms, with GSTP2 being one of the prominent ones. Mouse recombinant GSTP2 is often used in research to study the enzyme’s role in various physiological and pathological processes. The recombinant form is produced by cloning the GSTP2 gene into an expression vector, which is then introduced into a host cell (usually bacteria) to produce the enzyme in large quantities.
GSTP2 plays a crucial role in detoxifying a wide range of harmful compounds, including carcinogens, environmental toxins, and products of oxidative stress . It has been shown to protect cells from damage induced by these compounds, thereby reducing the risk of diseases such as cancer and liver toxicity .
Recent studies have highlighted the role of GSTP in modulating inflammatory responses. For instance, GSTP has been shown to play an anti-inflammatory role in macrophages, suggesting that it may have a protective role in inflammation . In a study involving experimental sepsis, deletion of the murine Gstp gene cluster significantly decreased mortality and reduced serum levels of high mobility group box-1 protein (HMGB1), a key cytokine involved in septic death . This indicates that GSTP may help prevent the translocation and release of HMGB1, thereby mitigating the severity of sepsis .
To better understand the role of GSTP in human physiology, researchers have developed mouse models that express human GSTP1. These models have provided valuable insights into the enzyme’s role in liver toxicity and drug metabolism . For example, mice expressing human GSTP1 showed different patterns of enzyme regulation and response to acetaminophen overdose compared to wild-type mice . This suggests that GSTP may be a critical determinant of toxin-induced hepatocyte injury, even when not expressed by hepatocytes .
