CARD17 Human
Description
Molecular Structure and Production
CARD17 Human is a 14.3 kDa recombinant protein produced in Escherichia coli. It comprises 133 amino acids (residues 1–110) fused to a 23-amino acid N-terminal histidine tag for purification . Key structural and production details include:
| Property | Specification |
|---|---|
| Molecular Weight | 14.3 kDa |
| Purity | >95% (SDS-PAGE) |
| Formulation | 20 mM Tris-HCl (pH 8.0), 0.15 M NaCl, 20% glycerol, 1 mM DTT |
| Storage | 4°C (short-term), -20°C (long-term); carrier protein recommended for stability |
CARD17 adopts a six-helix bundle fold characteristic of caspase recruitment domain (CARD) proteins, enabling interactions with caspase-1 and ASC (apoptosis-associated speck-like protein containing a CARD) .
Mechanism of Action in Inflammasome Regulation
CARD17 inhibits NLRP3 inflammasome activation by competitively binding to caspase-1 and ASC, preventing their polymerization into functional filaments . Key mechanistic insights:
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Filament Capping: CARD17 terminates caspase-1 filament elongation by occupying critical interaction surfaces (type Ia and IIIa interfaces) .
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Cytokine Suppression: Reduces IL-1β and IL-18 release in human and murine macrophages exposed to stimuli like monosodium urate (MSU) crystals .
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No NF-κB Activation: Unlike caspase-1, CARD17 does not induce NF-κB signaling, making it a selective inflammasome inhibitor .
Biophysical Characteristics
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Solubility: Monomeric in solution, unlike the filament-forming caspase-1 CARD domain .
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Binding Affinity: Inhibits caspase-1 polymerization with low nanomolar K<sub>i</sub> (≤10 nM) .
Comparative Analysis of CARD-Only Proteins (COPs)
| Feature | CARD17 (INCA) | CARD18 (ICEBERG) |
|---|---|---|
| Solubility | Soluble, monomeric | Insoluble, forms filaments |
| Sequence Identity | 83% vs. caspase-1 CARD | 53% vs. caspase-1 CARD |
| Function | Caspase-1 inhibition | Caspase-1 inhibition |
In Vitro Studies
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Human Macrophages: Stable expression of CARD17 in THP-1 cells reduced IL-1β release by >70% upon MSU crystal stimulation .
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Caspase-1 Inhibition: Cryo-EM structures revealed CARD17 disrupts caspase-1 filament assembly by occupying helical interfaces .
In Vivo Studies
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Transgenic Mice: Overexpression of human CARD17 ameliorated NLRP3-dependent inflammation, reducing cytokine release and pyroptosis .
Applications in Research and Development
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Drug Discovery: Serves as a template for designing inflammasome inhibitors targeting caspase-1 polymerization .
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Disease Models: Used to study gout, sepsis, and autoimmune disorders linked to dysregulated IL-1β .
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Limitations: Current studies rely on overexpression models; endogenous regulation mechanisms remain unclear .
Product Specs
Product Science Overview
Caspase Recruitment Domain Family, Member 17 (CARD17), also known as Inhibitory CARD (INCA), is a protein that plays a crucial role in the regulation of inflammation and apoptosis. It is part of the larger Caspase Recruitment Domain (CARD) family, which is involved in various cellular processes, including immune responses and cell death.
CARD17 is characterized by the presence of a CARD domain, which is a type of protein interaction module belonging to the death domain superfamily. This superfamily includes other domains such as the death effector domain and the pyrin domain. The CARD domain is typically involved in the regulation of apoptosis and inflammation by mediating protein-protein interactions.
CARD17 functions as a regulator of procaspase-1 (CASP1) activation. It is implicated in the regulation of the proteolytic maturation of pro-IL-1beta (IL1B) and its release during inflammation. Specifically, CARD17 inhibits the release of IL1B in response to lipopolysaccharide (LPS) in monocytes .
Recombinant CARD17 proteins are used in various research applications to study their role in inflammation and apoptosis. These proteins are produced using recombinant DNA technology, which allows for the expression of human CARD17 in various host systems. This enables researchers to investigate the protein’s function and interactions in a controlled environment .
