FAS1 Antibody
Description
Definition and Target
The FAS1 antibody specifically binds to the Fas receptor (TNFRSF6), a type I transmembrane protein encoded by the FAS gene. Fas contains:
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Extracellular domain: Rich in cysteine residues (157 amino acids) for ligand binding .
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Transmembrane domain: 17 amino acids anchoring the receptor to the cell membrane .
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Cytoplasmic death domain: 145 amino acids essential for recruiting FADD and initiating apoptosis .
Applications in Research
FAS1 antibodies are widely used in:
Role in Autoimmunity
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Mice lacking Fas in antigen-presenting cells (APCs) developed systemic autoimmunity, including elevated antinuclear antibodies (ANA) and splenomegaly .
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Fas-deficient B cells escaped T cell-mediated elimination, leading to lymphoproliferation and hyperimmunoglobulinemia .
Cancer Implications
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Fas activation by antibodies (e.g., clone CH11) induced apoptosis in prostate carcinoma and melanoma cells .
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Soluble Fas isoforms blocked apoptosis in vitro, suggesting a mechanism for tumor immune evasion .
Disease Associations
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Autoimmune Lymphoproliferative Syndrome (ALPS): FAS1 antibodies diagnose ALPS patients with FAS mutations .
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Cancer: Reduced Fas expression correlates with chemotherapy resistance, detectable via antibody-based assays .
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Neurodegeneration: Fas signaling modulates neuronal apoptosis in ALS and Alzheimer’s models, though mechanisms remain under study .
Technical Considerations
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Isoforms: Antibodies must distinguish membrane-bound Fas (pro-apoptotic) from soluble Fas (anti-apoptotic) .
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Activation: Clone CH11 mimics FasL binding, directly triggering apoptosis in functional assays .
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Cross-reactivity: Some antibodies (e.g., ab216991) recognize both human and mouse Fas, enabling translational studies .
Future Directions
Product Specs
Constituents: 50% Glycerol, 0.01M PBS, pH 7.4
Target Background
The FAS1 antibody targets a protein component of the chromatin assembly factor 1 (CAF-1) complex. CAF-1 plays a crucial role in chromatin assembly during DNA replication and repair. Specifically, FAS1 facilitates the assembly of histone octamers onto newly replicated DNA in vitro. This function is essential for various developmental processes, including seedling growth and leaf trichome differentiation. Furthermore, FAS1 is critical for maintaining the organization of the shoot apical meristem (SAM) and root apical meristem (RAM) during post-embryonic development by supporting the stable maintenance of gene expression patterns. While not essential for maintaining the transcriptional repression of heterochromatic genes, FAS1 is implicated in homologous recombination and may also repress endocycles.
Key Research Findings:
- CAF-1 ensures the stable inheritance of epigenetic states throughout Arabidopsis development (PMID: 16436052).
- In vitro studies demonstrate that FAS1 is required for nucleosome assembly onto newly replicated chromatin in both human cells and Arabidopsis thaliana (PMID: 16980538).
- FAS1 depletion significantly increases the frequency of somatic homologous recombination (HR) in plants (approximately 40-fold increase) (PMID: 17110925).
- The FAS1 gene, encoding the CAF-1 large subunit, is a direct target of E2F transcription factors (PMID: 17351056).
- Disruption of the CAF-1 pathway leads to cell cycle delays and arrest during pollen development, without affecting cell fate determination (PMID: 18045841).
- CAF-1 is essential for cell differentiation and regulates trichome development in conjunction with STICHEL via an endoreduplication-independent mechanism (PMID: 18477400).
Q&A
Experimental Design for FAS1 Antibody Studies
Q: How should I design an experiment to study the role of FAS1 using FAS1 antibodies in cell culture? A:
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Objective: Investigate the role of FAS1 in cellular processes.
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Materials: FAS1 antibody, cell lines, Western blot equipment, and appropriate controls.
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Procedure:
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Cell Culture: Maintain cells under optimal conditions.
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Treatment: Apply specific treatments to modulate FAS1 expression.
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Western Blot: Use FAS1 antibodies to detect changes in FAS1 protein levels.
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Data Analysis: Compare treated vs. control samples to assess FAS1's role.
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Data Interpretation and Contradictions
Q: How do I analyze and reconcile contradictory data from different FAS1 antibody experiments? A:
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Data Comparison: Compare results across different experiments, considering variables like antibody specificity, cell type, and experimental conditions.
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Controls: Ensure consistent use of positive and negative controls to validate results.
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Literature Review: Consult existing literature for similar findings or methodological insights.
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Reproducibility: Repeat experiments to confirm or refute initial findings.
Advanced Research Questions: FAS1 and Autophagy
Q: What is the relationship between FAS1 and autophagy, and how can I investigate this using FAS1 antibodies? A:
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Background: Autophagy involves the degradation of cellular components, and FAS1 has been linked to autophagic processes .
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Experimental Approach:
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Co-IP: Use FAS1 antibodies for co-immunoprecipitation with autophagy-related proteins.
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Western Blot: Analyze FAS1 levels in autophagy-deficient vs. proficient cells.
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Autophagy Inducers: Treat cells with autophagy inducers and assess FAS1 expression changes.
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Methodological Considerations for FAS1 Antibody Use
Q: What are the key methodological considerations when using FAS1 antibodies in research? A:
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Specificity: Ensure the antibody is specific to FAS1 and does not cross-react with other proteins.
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Optimization: Optimize antibody concentrations and incubation times for best results.
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Controls: Use appropriate controls to validate antibody specificity and efficiency.
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Sample Preparation: Properly prepare samples to maintain protein integrity.
Advanced Techniques: FAS1 and Apoptosis
Q: How can I investigate the role of FAS1 in apoptosis using FAS1 antibodies? A:
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Background: FAS1 may interact with apoptotic pathways, similar to other FAS proteins .
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Experimental Approach:
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Apoptosis Assays: Use apoptosis assays (e.g., Annexin V staining) to assess cell death in FAS1-modulated conditions.
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Western Blot: Analyze caspase activation in the presence of FAS1 antibodies.
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Co-IP: Investigate interactions between FAS1 and pro-apoptotic proteins.
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Troubleshooting Common Issues with FAS1 Antibodies
Q: What are common issues encountered when using FAS1 antibodies, and how can they be resolved? A:
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Non-Specific Binding: Use blocking agents and optimize antibody dilutions.
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Low Signal: Increase antibody concentration or incubation time.
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Background Noise: Optimize washing conditions and use appropriate controls.
Comparative Analysis of Different FAS1 Antibodies
Q: How can I compare the performance of different FAS1 antibodies in my research? A:
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Specificity and Sensitivity: Evaluate each antibody's specificity and sensitivity using Western blot or immunoprecipitation.
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Cross-Reactivity: Assess cross-reactivity with other proteins.
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Literature Review: Consult publications using these antibodies to gauge their reliability.
Quantitative Analysis of FAS1 Expression
Q: How can I quantify FAS1 expression levels using FAS1 antibodies? A:
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Western Blot: Use densitometry software to quantify band intensities relative to controls.
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ELISA: Develop or use commercial ELISA kits for quantitative analysis.
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Flow Cytometry: If applicable, use flow cytometry for cell surface FAS1 quantification.
Advanced Applications: FAS1 in Disease Models
Q: How can FAS1 antibodies be used to study disease models involving FAS1? A:
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Disease Models: Use FAS1 antibodies to investigate FAS1's role in disease models (e.g., cancer, metabolic disorders).
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Tissue Analysis: Perform immunohistochemistry to assess FAS1 expression in diseased tissues.
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Functional Studies: Conduct functional studies to understand FAS1's impact on disease progression.
Future Directions in FAS1 Research
Q: What are potential future directions for research involving FAS1 antibodies? A:
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Therapeutic Targets: Investigate FAS1 as a potential therapeutic target.
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Biomarker Development: Explore FAS1 as a biomarker for disease diagnosis or prognosis.
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Mechanistic Studies: Conduct detailed mechanistic studies to understand FAS1's role in cellular processes.
