The gene AT1G58390 (Arabidopsis thaliana) encodes a disease resistance protein belonging to the CC-NBS-LRR (Coiled-Coil-Nucleotide Binding Site-Leucine-Rich Repeat) class. These proteins are critical components of plant innate immunity, recognizing pathogen-associated molecular patterns (PAMPs) and triggering defense responses . While the gene itself is well-documented in plant pathology studies, no direct references to an At1g58390-specific antibody were identified in the reviewed literature.
Although no antibody for AT1G58390 exists in public databases, antibodies targeting CC-NBS-LRR proteins are pivotal in studying plant-pathogen interactions. Below is a synthesis of relevant antibody applications and findings:
Antibodies are generated through somatic recombination and hypermutation, enabling recognition of diverse antigens . In plant research, antibodies are often engineered to:
Localize proteins (e.g., CC-NBS-LRR receptors in membrane-bound or cytoplasmic compartments).
Quantify protein expression during pathogen infection.
Inhibit protein function (e.g., blocking activation of downstream signaling pathways).
For CC-NBS-LRR proteins like AT1G58390, hypothetical antibody applications might include:
Immunoprecipitation to study protein-protein interactions.
Immunohistochemistry to map subcellular localization during infection.
ELISA to monitor protein abundance under biotic stress.
The development of antibodies for plant proteins like AT1G58390 faces hurdles:
Low immunogenicity: Plant proteins may lack epitopes recognized by mammalian immune systems.
Cross-reactivity: Antibodies may bind conserved motifs in related CC-NBS-LRR proteins .
Validation complexity: Limited availability of plant protein standards for assay optimization.
To address gaps in AT1G58390 antibody research, consider:
At1g58390 is a resistance gene (R-gene) in Arabidopsis thaliana that belongs to the family of genes involved in plant immunity. Like other R-genes, it likely plays a crucial role in the plant's defense system, specifically in effector-triggered immunity (ETI), which is the second layer of the plant immune system that responds to specific pathogen effectors. The plant immune system consists of two primary defense levels: MAMP-triggered immunity (MTI) responding to conserved microbial patterns, and ETI that recognizes specific pathogen effectors . Antibodies against At1g58390 allow researchers to study its expression patterns, protein interactions, and subcellular localization, providing insights into its function during pathogen challenges and potentially developing enhanced disease resistance in agricultural applications.
Researchers can develop several types of antibodies against At1g58390, each with specific applications. Polyclonal antibodies recognize multiple epitopes of At1g58390 and are useful for general detection but may cross-react with similar R-genes. Monoclonal antibodies target a single epitope, offering higher specificity but potentially limited sensitivity. Nanobodies (single-domain antibodies) represent a valuable alternative as they can better access conformational epitopes of membrane-associated proteins like many R-genes . Additionally, researchers can develop antibodies that specifically recognize phosphorylated or other post-translationally modified forms of At1g58390 to study its activation state during immune responses.
Antibody validation for At1g58390 requires a multi-faceted approach. First, perform Western blot analysis using protein extracts from wild-type plants and At1g58390 knockout mutants to confirm the antibody detects a band of the expected molecular weight only in wild-type samples. Second, conduct immunoprecipitation followed by mass spectrometry to verify the antibody pulls down At1g58390. Third, use the antibody for immunolocalization studies and compare results with GFP-tagged At1g58390 expression patterns. Fourth, test for cross-reactivity with closely related R-genes, particularly those in the same subfamily or cluster type, similar to the validation approach used for other R-genes in A. thaliana . Finally, evaluate antibody performance across different experimental conditions to ensure consistent specificity.
Yeast-based systems offer several significant advantages over traditional animal immunization methods for generating At1g58390 antibodies. First, the process is considerably faster, taking 3-6 weeks compared to 3-6 months with animal immunization . Second, it eliminates ethical concerns and regulatory requirements associated with animal use. Third, yeast display libraries containing millions of synthetic antibody variants provide greater diversity than an animal's immune repertoire, potentially yielding antibodies with higher specificity and affinity. Fourth, the system allows direct selection for antibodies that recognize specific conformational states of At1g58390, which is particularly valuable for studying its activation during immune responses. Fifth, the yeast-based approach is more reproducible and less variable than animal immunization, which depends on individual animal immune responses. Finally, once established, the yeast library represents a renewable resource that can be used repeatedly for selecting antibodies against different epitopes or conformational states of At1g58390 .
Developing nanobodies against At1g58390 using synthetic libraries involves a systematic approach. Begin by creating or obtaining a diverse yeast display library of approximately 500 million synthetic camelid antibodies, each expressed on the yeast cell surface . Purify and fluorescently label the At1g58390 protein, ensuring it maintains its native conformation. Incubate the labeled protein with the yeast library to allow binding to nanobodies with affinity for At1g58390. Use fluorescence-activated cell sorting (FACS) to isolate yeast cells displaying nanobodies that bind to At1g58390 . Sequence the DNA from these positive clones to identify the nanobody sequences. Express selected nanobodies in E. coli for large-scale production and purification. Finally, characterize the nanobodies for specificity, affinity, and functionality in relevant immunoassays. This method avoids the need for animal immunization and can yield highly specific nanobodies within 3-6 weeks, significantly faster than traditional methods .
The choice of expression system for generating At1g58390 antigen depends on your specific research needs. For full-length At1g58390 protein, a plant-based expression system (such as Nicotiana benthamiana) is optimal as it provides proper folding and post-translational modifications relevant to plant proteins. For generating antibodies against specific domains, a bacterial expression system using E. coli can efficiently produce the NBS or LRR domains separately, though these may lack plant-specific modifications. Insect cell systems (like Sf9 or Hi5) represent an intermediate option that can handle complex proteins with some post-translational modifications. Yeast systems (P. pastoris) provide eukaryotic processing with higher yields than mammalian cells. When selecting the expression system, consider that R-genes like At1g58390 often contain hydrophobic regions and multiple domains that may affect proper folding . Each system has trade-offs between yield, cost, ease of purification, and preservation of native protein structure that should be evaluated based on the intended use of the antibody.
At1g58390 antibodies provide powerful tools for studying expression patterns under varying environmental conditions. Design experiments with Arabidopsis plants exposed to different temperatures, humidity levels, and light conditions, as climate variables can influence R-gene expression and pathogen interactions . Collect tissue samples at consistent time points and extract proteins using buffers optimized for membrane-associated proteins. Perform quantitative Western blots using the At1g58390 antibody with appropriate loading controls to measure relative protein levels. For spatial distribution analysis, use immunohistochemistry to visualize At1g58390 localization in different tissues. Complement protein-level studies with RT-qPCR to assess transcript levels, using validated primers targeting At1g58390-specific regions . Compare protein and transcript levels to identify post-transcriptional regulation. For comprehensive analysis, include control plants and R-gene mutants to establish baseline expression and antibody specificity. This approach allows correlation of R-gene expression with environmental variables known to influence plant immunity, such as temperature seasonality and humidity levels that affect pathogen pressure .
Successful co-immunoprecipitation (co-IP) experiments with At1g58390 antibodies require careful optimization. Begin with fresh plant tissue collected under conditions where At1g58390 is known to be expressed and active, possibly including pathogen challenge to capture interaction partners during immune responses. Use a gentle extraction buffer containing 0.5-1% non-ionic detergent (e.g., NP-40 or Triton X-100) to maintain protein-protein interactions while solubilizing membrane-associated proteins like R-genes . Pre-clear lysates with protein A/G beads to reduce non-specific binding. Immobilize At1g58390 antibodies on protein A/G beads, or better yet, directly conjugate to magnetic beads to minimize antibody contamination in the final sample. Include appropriate negative controls such as IgG from the same species and lysates from At1g58390 knockout plants. Perform stringent washing steps but avoid harsh conditions that might disrupt legitimate interactions. Elute bound proteins and analyze by mass spectrometry, focusing on proteins enriched compared to control samples. Validate key interactions through reciprocal co-IP or other methods like bimolecular fluorescence complementation. This approach can reveal proteins interacting with At1g58390 during immune responses, helping elucidate its role in disease resistance signaling pathways.
Confocal microscopy with At1g58390 antibodies offers valuable insights into the protein's dynamic localization during pathogen infection. Start by growing Arabidopsis plants under controlled conditions and inoculate with relevant pathogens at different time points (0, 2, 6, 12, 24, and 48 hours). Fix tissue samples with paraformaldehyde while preserving cellular structures, then permeabilize cell membranes to allow antibody penetration. Incubate with validated At1g58390 primary antibodies followed by fluorophore-conjugated secondary antibodies. Include co-staining with organelle markers such as nuclear, membrane, endoplasmic reticulum, and vesicle markers to precisely determine subcellular localization. Capture high-resolution z-stack images using confocal microscopy and perform deconvolution to enhance spatial resolution. Quantify colocalization using appropriate software and statistical analysis. Compare localization patterns between mock-treated and pathogen-infected samples to track At1g58390 movement during immune responses. This approach can reveal critical insights into the protein's function, such as whether it relocates from the cytoplasm to the nucleus upon pathogen detection, associates with specific membranes, or forms discrete protein complexes during ETI responses .
The relationship between At1g58390 protein and transcript levels across Arabidopsis accessions provides insights into post-transcriptional regulation mechanisms. To investigate this correlation, design an experiment examining both transcript and protein levels in multiple accessions grown under identical conditions. Select diverse accessions representing different climate origins, as natural populations of A. thaliana show genetic variation in R-gene expression related to local adaptation . For transcript quantification, use RT-qPCR with primers specifically designed for At1g58390 (see table below for primer design considerations). For protein quantification, perform quantitative Western blotting using validated At1g58390 antibodies. Calculate correlation coefficients between transcript and protein levels, and analyze whether this correlation changes under different environmental conditions or pathogen challenges.
| Primer Design Considerations for At1g58390 qRT-PCR |
|---|
| Target unique regions to avoid cross-amplification of related R-genes |
| Design primers spanning exon-exon junctions when possible |
| Optimal amplicon size: 80-150 bp for efficient amplification |
| Include at least three reference genes for normalization |
| Validate primer efficiency (90-110%) using standard curves |
| Test primers on cDNA from various accessions to ensure consistent amplification |
When different At1g58390 antibodies yield contradictory results, a systematic troubleshooting approach is necessary. First, comprehensively characterize each antibody by determining their exact epitopes through epitope mapping techniques, which will reveal whether they recognize different domains of At1g58390. Second, assess antibody specificity through Western blots against recombinant At1g58390 fragments and knockout mutant controls to identify potential cross-reactivity with related R-genes or non-specific binding . Third, examine whether certain antibodies recognize specific conformational states or post-translationally modified forms of At1g58390, as R-gene activation often involves conformational changes .
Conduct parallel experiments using multiple detection methods including Western blot, immunoprecipitation, and immunofluorescence with each antibody. Generate a GFP-tagged At1g58390 construct as an independent validation method. Test antibodies under different experimental conditions, including various fixation methods for microscopy or different lysis buffers for Western blots, as these factors can affect epitope accessibility.
Create a decision tree for selecting the most appropriate antibody based on the specific application and experimental conditions. Finally, consider that apparent contradictions might reflect biologically meaningful differences in protein states rather than technical artifacts, potentially revealing novel insights about At1g58390 regulation and function in plant immunity.
While R-genes like At1g58390 are traditionally considered cytoplasmic receptors, emerging evidence suggests some may relocate to the nucleus and influence transcription during immune responses. Chromatin immunoprecipitation followed by sequencing (ChIP-seq) with At1g58390 antibodies can elucidate potential roles in transcriptional regulation. Begin by treating Arabidopsis plants with pathogen-associated molecular patterns or specific pathogens to activate immune responses. Harvest tissue at multiple time points (0, 2, 6, 12, and 24 hours) and perform crosslinking to preserve protein-DNA interactions. Sonicate chromatin to appropriate fragment sizes (200-500 bp) and perform immunoprecipitation with validated At1g58390 antibodies, using pre-immune serum as a negative control.
After library preparation and sequencing, analyze data to identify genomic regions enriched for At1g58390 binding. Compare binding profiles between naïve and pathogen-challenged plants to identify condition-specific interactions. Perform motif analysis to identify potential DNA binding sequences and integrate with RNA-seq data to correlate binding events with gene expression changes. Validate key targets with ChIP-qPCR and reporter gene assays. This approach could reveal unexpected functions of At1g58390 in directly or indirectly influencing gene expression during immune responses, similar to how other R-gene regulators have been shown to affect transcriptional networks in plants .
Several technical challenges commonly arise when using At1g58390 antibodies for Western blot analysis. First, R-gene proteins like At1g58390 are often expressed at low levels in plants, making detection difficult without enrichment or sensitive detection methods . To overcome this, optimize protein extraction using buffers containing appropriate detergents (0.5-1% NP-40 or Triton X-100) to solubilize membrane-associated proteins, and consider using plant tissue where R-gene expression is elevated, such as during pathogen challenge. Second, cross-reactivity with related R-genes can occur due to sequence similarity within R-gene families . Validate specificity using knockout mutants and recombinant protein controls.
Third, the large size of many R-gene proteins (often >100 kDa) can make efficient transfer challenging. Use lower percentage gels (6-8%) and optimize transfer conditions with extended times or lower voltages. Fourth, post-translational modifications or conformational states may affect antibody recognition; consider denaturing conditions that fully expose epitopes. Finally, many commercially available R-gene antibodies have poor validation records. Thoroughly test each new antibody lot with positive and negative controls. The table below summarizes optimization strategies for Western blot analysis of At1g58390:
| Western Blot Optimization for At1g58390 Detection |
|---|
| Use freshly prepared, ice-cold extraction buffers with protease inhibitors |
| Include membrane solubilization detergents appropriate for R-genes |
| Load >50 μg total protein per lane to detect low-abundance R-genes |
| Use 6-8% gels for better resolution of high molecular weight proteins |
| Optimize transfer conditions (lower voltage, longer time, add SDS to transfer buffer) |
| Block with 5% BSA instead of milk if phospho-specific antibodies are used |
| Extend primary antibody incubation (overnight at 4°C) |
| Consider enhanced chemiluminescence or fluorescent secondary antibodies for detection |
Preserving the native conformation of At1g58390 during immunoprecipitation is critical for studying protein interactions and functional states. Begin with gentle extraction conditions using buffers containing mild detergents (0.1-0.5% digitonin or CHAPS) that solubilize membranes while maintaining protein structures. Keep all solutions and samples cold (4°C) throughout the procedure to prevent protein denaturation. Use physiological pH (7.2-7.4) and salt concentrations (150 mM NaCl) in buffers to maintain native protein interactions. Add protease inhibitors and, when studying phosphorylation states, phosphatase inhibitors to prevent post-extraction modifications.
Consider using antibodies that recognize conformational epitopes rather than linear epitopes, as the former are more likely to immunoprecipitate the protein in its native state. Pre-clear lysates with protein A/G beads to reduce non-specific binding. When possible, use direct conjugation of antibodies to beads rather than protein A/G capture to minimize harsh elution conditions. For elution, use gentle methods such as competitive elution with excess epitope peptide rather than denaturing conditions. Validate the conformational integrity of immunoprecipitated At1g58390 by testing its functional properties, such as ATP binding capability (as R-genes like At1g58390 typically have nucleotide-binding domains ) or by circular dichroism spectroscopy to assess secondary structure preservation.
Distinguishing true At1g58390 interactions from background noise in immunoprecipitation-mass spectrometry (IP-MS) experiments requires robust analytical approaches. First, implement a comprehensive experimental design with appropriate controls including IgG control immunoprecipitations, samples from At1g58390 knockout plants, and technical replicates to establish a baseline for non-specific binding. Apply statistical analysis using tools like SAINTexpress or MIST that calculate probability scores for true interactions based on spectral counts or intensity values compared to controls.
Use quantitative filters such as fold-change thresholds (typically >2-fold enrichment over controls) and statistical significance cutoffs (p < 0.05 or FDR < 0.1) to identify high-confidence interactors. Implement contaminant repositories like the CRAPome to filter out common contaminants in IP-MS experiments. Visualize data using volcano plots highlighting proteins that meet both fold-change and statistical significance criteria.
Prioritize candidates based on biological relevance, considering known immune pathway components and proteins with domains capable of interacting with NBS-LRR proteins like At1g58390 . Validate top candidates using orthogonal approaches such as reciprocal IP, in vitro binding assays, or bimolecular fluorescence complementation. Additionally, perform network analysis to identify functional protein clusters, which can reveal biological pathways associated with At1g58390 function during immune responses. This integrated approach maximizes confidence in identified interactors while minimizing false positives.