FAB1D Antibody
Description
Definition and Biological Context
FAB1D refers to a noncanonical isoform of the phosphatidylinositol 3-phosphate 5-kinase (PI3P5K) family in plants. Unlike canonical isoforms (e.g., FAB1A/B), FAB1D lacks a FYVE domain, a zinc-binding motif critical for phosphoinositide recognition. Despite structural differences, FAB1D retains functional roles in membrane trafficking, vacuolar pH regulation, and reactive oxygen species (ROS) homeostasis .
Functional Characterization of FAB1D
Key roles identified in Arabidopsis thaliana:
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Membrane Recycling: FAB1D collaborates with FAB1B to regulate endosomal trafficking and vacuolar morphology in pollen tubes .
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ROS Homeostasis: FAB1D modulates ROS production, critical for cellular signaling and stress responses .
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Lateral Root Development: FAB1D uniquely suppresses lateral root formation, contrasting with other isoforms (e.g., FAB1B) .
Functional Redundancy and Specificity
| Feature | FAB1D | FAB1B |
|---|---|---|
| Subcellular Localization | Cytoplasm | ER-like structures/vacuoles |
| Domain Composition | No FYVE domain | Contains FYVE domain |
| Lateral Root Regulation | Inhibits formation | No direct role |
| ROS Modulation | Required for homeostasis | Partially redundant with FAB1D |
Antibody Development and Applications
While FAB1D-specific antibodies are not explicitly detailed in current literature, methodologies for antibody discovery against similar targets include:
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Microfluidics-enabled Screening: High-throughput platforms for isolating antigen-specific monoclonal antibodies (e.g., SARS-CoV-2 spike protein) .
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LC-MS Fab Profiling: Quantitative analysis of antigen-specific IgG1 repertoires, applicable to autoantibodies like anti-citrullinated protein antibodies (ACPAs) .
Antibody Engineering Techniques
| Technology | Application | Example Target |
|---|---|---|
| Phage Display Libraries | Synthetic Fab libraries (e.g., Ylanthia) | TNF-α, M-CSF, ErbB4 |
| MAGMA-seq | Wide mutational scanning of Fab libraries | SARS-CoV-2 S1 |
Challenges and Research Gaps
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Antibody Specificity: No commercial or research-grade FAB1D antibodies are reported in the provided sources. Current antibody tools (e.g., anti-FABP1) target unrelated proteins.
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Structural Insights: FAB1D’s cytoplasmic localization and lack of FYVE domain suggest unique interaction interfaces, necessitating structural studies for antibody design .
Future Directions
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Targeted Immunogen Design: Leverage FAB1D’s unique sequence (e.g., kinase domain) for epitope selection.
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Functional Blocking Studies: Develop FAB1D inhibitors to elucidate its role in ROS signaling and root development.
Product Specs
Constituents: 50% Glycerol, 0.01M PBS, pH 7.4
Target Background
Q&A
Given the lack of specific information on "FAB1D Antibody" in the search results, I will create a general FAQ for researchers on antibodies, focusing on experimental design, data analysis, and methodological considerations. This approach will ensure that the FAQs are relevant to academic research scenarios involving antibodies.
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To validate antibody specificity, use a combination of techniques such as Western blot, immunofluorescence (IF), and ELISA. Ensure that the antibody binds specifically to the target antigen and not to non-specific proteins. For IF, validate the correct subcellular localization of the target protein . Use controls like cells lacking the target protein to confirm specificity.
A:
Consider the type of assay (e.g., Western blot, IF, ELISA), the desired half-life of the antibody, and whether effector functions like ADCC or CDC are needed. For instance, IgG1 is commonly used for its effector functions, while IgG4 may be preferred for reduced effector activity .
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Ensure consistency across different lots of the antibody and use optimized protocols for each assay type. Validate results by repeating experiments and using multiple detection methods. Consider potential sources of variability, such as fixation and permeabilization conditions for IF .
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Common pitfalls include non-specific binding and incorrect subcellular localization. Avoid these by using controls, optimizing assay conditions, and validating specificity through multiple methods .
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Antibody engineering involves modifying the variable regions (e.g., complementarity-determining regions) to enhance specificity or affinity. Techniques include phage display, yeast display, and rational design based on structural information .
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Antibody fragments like Fab and scFv are useful for their smaller size and reduced immunogenicity. They can be generated through enzymatic digestion (e.g., using papain for Fab) or recombinant expression techniques .
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Consider factors such as expression titer, aggregation, and long-term stability. Humanization of non-human antibodies can improve manufacturability by reducing immunogenicity and enhancing expression in human-compatible systems .
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Check for lot-to-lot variability, ensure proper storage and handling of the antibody, and optimize assay conditions (e.g., antibody concentration, fixation methods). Validate results using alternative detection methods .
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Strategies include Fc engineering to modify interactions with FcRn receptors, which can prolong the half-life of antibodies by reducing clearance .
Example Data Table: Antibody Formats and Their Characteristics
| Antibody Format | Half-Life | Effector Functions | Applications |
|---|---|---|---|
| IgG1 | Long | ADCC, CDC | Therapeutic |
| IgG4 | Long | Reduced effector | Therapeutic |
| Fab | Short | No effector | Diagnostic |
| scFv | Short | No effector | Diagnostic |
