gAcrp30 Mouse
Description
Mechanism of Action
gAcrp30 exerts its effects primarily via activation of AMP-activated protein kinase (AMPK), a key regulator of energy metabolism . This mechanism is distinct from full-length ACRP30, which lacks AMPK activation .
Key Signaling Pathways
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AMPK Activation:
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ACC Inhibition:
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Glucose Transport:
Metabolic Outcomes
Time-Course Effects
| Time (min) | AMPK Activity | ACC Phosphorylation | Malonyl-CoA |
|---|---|---|---|
| 15 | 1.5× increase | Minimal change | – |
| 30 | 2× increase | Significant increase | −30% |
| 60 | Baseline | Sustained increase | −30% |
Data derived from in vitro and in vivo studies .
Applications in Research
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Cell Culture: Used to study fatty acid oxidation and glucose uptake in muscle cells .
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Bioassays: ED50 for AMPK activation in EDL muscle is 5–20 µg/mL .
Comparative Efficacy with Full-Length ACRP30
References
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Fruebis et al. (2001). PNAS.
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Tomas et al. (2002). PNAS.
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Fruebis et al. (2001). PNAS.
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Tomas et al. (2002). PMC.
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R&D Systems. Recombinant Mouse gAdiponectin/gAcrp30 Protein.
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Fruebis et al. (2001). PMC.
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Thermo Fisher. Mouse gAcrp30 Recombinant Protein.
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Nordic Diagnostica. gAcrp30 Globular Adiponectin Mouse.
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Berg et al. (2001). PMC.
Product Specs
MAYMYRSAFS VGLETRVTVP NVPIRFTKIF YNQQNHYDGS TGKFYCNIPG LYYFSYHITVYMKDVKVSLF KKDKAVLFTY DQYQEKNVDQ ASGSVLLHLE VGDQVWLQVY GDGDHNGLYADNVNDSTFTG FLLYHDTN
Q&A
What is gAcrp30, and how is it derived?
gAcrp30, also known as the globular domain of adipocyte complement-related protein (30 kDa), is a proteolytic cleavage product of adiponectin. Adiponectin is a secreted protein exclusively expressed in differentiated adipocytes. The cleavage process isolates the globular head domain, which has distinct biological properties compared to full-length adiponectin .
Adiponectin itself circulates in serum as oligomers (trimeric, hexameric, and higher molecular weight forms). The globular domain (gAcrp30) forms homotrimers and interacts with specific receptors, AdipoR1 and AdipoR2, to mediate its effects primarily on muscle and liver tissues . This domain is pharmacologically active, influencing pathways related to fatty acid oxidation, glucose uptake, and energy homeostasis.
How does gAcrp30 influence metabolic pathways in mouse models?
gAcrp30 exerts its effects by activating AMP-activated protein kinase (AMPK), a critical enzyme involved in cellular energy regulation. In skeletal muscle tissues such as the extensor digitorum longus (EDL) and gastrocnemius muscles, gAcrp30 enhances AMPK activity and phosphorylation . This activation leads to downstream effects including:
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Increased fatty acid oxidation via inactivation of acetyl-CoA carboxylase (ACC).
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Reduction in malonyl-CoA concentrations.
In vivo studies demonstrate that administration of gAcrp30 to mice results in transient activation of AMPK followed by sustained alterations in malonyl-CoA levels and ACC activity. These changes collectively improve insulin sensitivity and promote weight loss without affecting food intake .
What experimental models are commonly used to study gAcrp30?
Researchers utilize both in vitro and in vivo models to investigate the biological functions of gAcrp30:
In Vitro Models
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Cell Culture Systems: Cultured muscle cells are incubated with purified gAcrp30 to assess its effects on fatty acid oxidation and glucose uptake .
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Tissue Homogenates: Muscle tissues are treated with gAcrp30 to measure enzymatic activity changes, such as AMPK phosphorylation .
In Vivo Models
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Mouse Models: C57BL/6J mice are frequently used for metabolic studies involving gAcrp30. Acute or chronic administration evaluates systemic effects such as plasma free fatty acid reduction, weight loss, and insulin sensitivity improvement .
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Diet-Induced Obesity Models: Mice fed high-fat diets are treated with gAcrp30 to study its impact on obesity-related metabolic dysfunctions .
These models enable researchers to dissect the molecular mechanisms underlying gAcrp30's pharmacological actions.
What are the signaling pathways activated by gAcrp30?
The primary signaling pathway activated by gAcrp30 involves AMPK. This enzyme acts as an energy sensor within cells, regulating metabolic processes under conditions of energy stress. Upon activation by gAcrp30:
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AMPK phosphorylates ACC at Ser-79, leading to its inactivation.
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Inactivation of ACC reduces malonyl-CoA levels, thereby promoting mitochondrial fatty acid oxidation.
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Enhanced fatty acid oxidation contributes to improved energy homeostasis and insulin sensitivity .
Additionally, gAcrp30 may interact with other signal transduction proteins beyond AMPK, although these pathways remain less characterized .
How does gAcrp30 differ from full-length adiponectin in function?
While both gAcrp30 and full-length adiponectin originate from the same precursor protein, their biological activities differ significantly:
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gAcrp30: Exhibits potent effects on peripheral tissues by enhancing fatty acid oxidation and glucose uptake independently of insulin. It also promotes weight loss in mouse models without reducing food intake .
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Full-Length Adiponectin: Circulates primarily as oligomers with broader systemic roles including anti-inflammatory effects and modulation of immune responses .
Experimental evidence indicates that full-length adiponectin does not activate AMPK or induce similar metabolic changes as observed with gAcrp30 administration .
What are the methodological challenges in studying gAcrp30?
Studying gAcrp30 presents several challenges that researchers must address:
Protein Purification
Obtaining biologically active recombinant gAcrp30 requires precise proteolytic cleavage of adiponectin followed by rigorous purification steps to ensure structural integrity and functionality .
Dosage Optimization
Determining effective dosages for in vitro and in vivo experiments is critical. Studies suggest that concentrations ranging from 2.5 μg/mL (for cell cultures) to 75 μg (for mouse models) yield measurable biological effects without toxicity .
Temporal Dynamics
The transient nature of AMPK activation by gAcrp30 necessitates careful timing in experimental designs to capture early signaling events versus sustained metabolic changes .
Receptor Specificity
Understanding interactions between gAcrp30 and its receptors (AdipoR1/R2) requires advanced techniques such as receptor binding assays and gene knockout models .
Can contradictions arise in data involving gAcrp30 research?
Yes, contradictions can emerge due to differences in experimental conditions or model systems used:
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Tissue-Specific Effects: For example, while EDL muscle shows significant AMPK activation upon gAcrp30 treatment, soleus muscle exhibits minimal changes under similar conditions .
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Species Variability: Findings from mouse models may not always translate directly to human physiology due to interspecies differences in receptor expression or metabolic pathways .
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Oligomeric Forms: Variations in the oligomeric state of adiponectin (trimer vs hexamer) can influence experimental outcomes when comparing full-length adiponectin with its globular domain .
Addressing these contradictions requires standardized protocols and cross-validation across multiple experimental systems.
What advanced techniques are employed for quantifying gAcrp30 activity?
Quantification of gAcrp30 activity involves sophisticated methodologies:
ELISA
Enzyme-linked immunosorbent assays (ELISA) provide quantitative measurements of gAcrp30 concentrations in biological samples such as serum or tissue homogenates. These assays utilize monoclonal antibodies specific for mouse adiponectin/gAcrp30 .
Western Blotting
Western blot analysis detects phosphorylation states of key enzymes like AMPK and ACC following treatment with gAcrp30.
Mass Spectrometry
Mass spectrometry characterizes post-translational modifications of gAcrp30 that may influence its biological activity.
Metabolic Flux Analysis
Real-time assessment of fatty acid oxidation rates using radiolabeled substrates elucidates the functional impact of gAcrp30 on cellular metabolism.
These techniques collectively enhance the precision and reliability of research findings.
Product Science Overview
Adiponectin, also known as Acrp30, is a member of the complement factor C1q family. It consists of several domains:
- Signal Sequence: Directs the protein to its proper location in the cell.
- Non-homologous Sequence: Unique to adiponectin.
- Collagen Domain: Involved in the formation of higher-order structures.
- Globular Domain: The focus of this article, known for its potent biological effects .
Recombinant globular adiponectin is typically expressed in Escherichia coli to ensure high purity and biological activity. The recombinant form is often used in research to study its effects on various metabolic processes .
Globular adiponectin has several key functions:
- Metabolic Regulation: It enhances glucose utilization and fatty acid oxidation, making it a critical player in maintaining energy homeostasis .
- Anti-inflammatory Effects: It antagonizes TNF-alpha, a pro-inflammatory cytokine, thereby reducing inflammation in tissues such as the liver and macrophages .
- Insulin Sensitivity: By stimulating AMPK phosphorylation in the liver and skeletal muscle, it improves insulin sensitivity, which is beneficial for managing diabetes .
Due to its significant role in metabolism and inflammation, globular adiponectin is widely used in research:
- Diabetes Research: Its ability to enhance insulin sensitivity makes it a valuable tool for studying diabetes and potential treatments .
- Obesity Studies: Given its role in fat metabolism, it is often used to understand obesity and related metabolic disorders .
- Cardiovascular Research: Its anti-inflammatory properties are explored for potential benefits in cardiovascular diseases .
