The AT5G08680 locus is one of three tandemly duplicated genes (AT5G08670, AT5G08680, and AT5G08690) encoding identical mature proteins in Arabidopsis. Key characteristics include:
Despite its lack of expression under tested conditions, AT5G08680 shares 100% amino acid identity with its homologs AT5G08670 and AT5G08690 in the mature protein region .
The AT5G08680 antibody has been utilized to investigate mitochondrial ATP synthase roles in plastid retrograde signaling. Key findings include:
Loss-of-Function Mutants:
SALK T-DNA insertion lines (SALK_039723 and SALK_145131) showed reduced mitochondrial ATP synthase levels, leading to:
RNA-Seq Analysis:
| Condition | Differentially Expressed Genes (DEGs) | Key Pathways Affected |
|---|---|---|
| Wild-type vs. Mutants | 1,864 DEGs identified | Mitochondrial electron transport chain |
| Lincomycin Treatment | Enhanced stress-response gene suppression | Plastid-mitochondria communication |
Western Blot: Used to confirm reduced ATP synthase beta-subunit levels in mutants .
Subcellular Localization: GFP fusion assays confirmed mitochondrial targeting .
Redundant Gene Function: The identical protein products of AT5G08670/80/90 complicate isoform-specific studies .
Expression Variability: Lack of AT5G08680 expression in standard assays limits its standalone functional analysis .
CRISPR-Cas9 Knockouts: To disentangle functional redundancy among homologs.
Stress-Response Assays: Investigate AT5G08680 induction under uncharacterized environmental conditions.
At5g08680 encodes a protein with ATP binding and helicase activity in Arabidopsis thaliana. Developing antibodies against this protein enables researchers to study its expression patterns, subcellular localization, protein-protein interactions, and functional role in plant development. The methodological approach requires first characterizing the target protein's biochemical properties to determine optimal epitope selection. When designing experiments, researchers should consider using both monoclonal and polyclonal antibodies for validation, as each offers distinct advantages in specificity and sensitivity for different experimental applications.
For optimal production of At5g08680 antibodies, expression in human HEK293F cells has demonstrated significant advantages for plant protein-directed antibodies requiring complex post-translational modifications. The methodological approach involves:
Cloning the At5g08680 sequence into appropriate expression vectors
Transfecting the constructs into HEK293F cells with a 1:1.5 molar ratio of heavy and light chain plasmids
Culturing cells in SMM 293-TII medium at 310K and 5% CO₂
Collecting supernatants after 5 days
Purifying through 0.22 μm membrane filtration
Further purification via protein A chromatography and size-exclusion chromatography
This system typically yields 5-10 mg/liter of purified antibody with proper conformation for plant protein recognition .
The methodological approach for validating At5g08680 antibody specificity should incorporate multiple complementary techniques:
| Validation Method | Technical Parameters | Expected Outcomes |
|---|---|---|
| Western Blot | SDS-PAGE separation, transfer to membrane, antibody dilution 1:1000-1:5000 | Single band at predicted molecular weight |
| Immunoprecipitation | Protein A/G beads, lysate concentration 1-2 mg/ml | Enrichment of At5g08680 protein |
| ELISA | Coating concentration 50 μg/mL, serial antibody dilutions | EC₅₀ determination for binding affinity |
| Immunofluorescence | Fixation with 4% paraformaldehyde, antibody dilution 1:200-1:500 | Expected subcellular localization pattern |
| Knockout/knockdown controls | CRISPR-Cas9 or RNAi lines | Absence or reduction of signal |
Comparing recognition patterns between the target antibody and a commercially available reference can provide additional validation. Cross-reactivity testing against related Arabidopsis proteins should be performed to ensure specificity .
For discriminating between At5g08680 protein variants or post-translational modifications, implement a parametric selection strategy combining Box-Cox data transformation with statistical testing. The methodological workflow involves:
Transform antibody response data using optimal Box-Cox parameters (λ within -4 to 4 range)
Determine if data follows single or bimodal distribution patterns
For bimodal distributions, establish optimal cut-off points by maximizing chi-squared statistics
For single population distributions, apply linear regression models with and without the variant as covariate
Compare models using Wilk's likelihood ratio test at 5% significance threshold
For non-parametric datasets, implement Mann-Whitney tests to compare median values
Adjust all p-values using Benjamini-Yekutieli procedure (FDR 5%)
This approach significantly improves discrimination power between protein variants compared to standard selection methods, as evidenced by increased AUC values from 0.68 to 0.80 in similar applications .
To study At5g08680 protein interactions, implement a multi-faceted experimental design that combines:
Co-immunoprecipitation with At5g08680 antibodies followed by mass spectrometry
Proximity labeling using antibody-enzyme fusion constructs (BioID or APEX2)
Surface plasmon resonance (SPR) assays with the following parameters:
Sensor chip: CM5 with N-hydroxysuccinimide and N-ethyl-N-(3-diethylaminopropyl) carbodiimide activation
Running buffer: 10 mM HEPES, 150 mM NaCl, 3 mM EDTA
Flow rate: 30 μL/minute
Baseline acquisition: 100 seconds
Antibody injection: Serial dilutions at 30 μL/minute for 100 seconds
Analysis: Determination of kon/koff ratios to calculate Kd values
For complex interaction networks, combine these approaches with computational modeling. This integrative strategy provides higher confidence in identifying true interactors versus false positives that may appear in single-method approaches .
When facing contradictory localization data, implement the following systematic troubleshooting approach:
Antibody validation reassessment:
Verify epitope accessibility in different fixation conditions
Test multiple antibodies targeting different epitopes of At5g08680
Perform peptide competition assays to confirm specificity
Technical optimization:
Compare different fixation methods (paraformaldehyde, methanol, acetone)
Adjust permeabilization conditions (0.1-0.5% Triton X-100 or saponin)
Optimize antibody concentration and incubation times
Biological verification:
Implement fluorescent protein tagging as complementary approach
Consider developmental stage and tissue-specific expression
Evaluate condition-dependent localization (stress, developmental stage)
Super-resolution microscopy techniques:
STED or STORM imaging for nanoscale resolution
Live-cell imaging to track dynamic localization
This methodological approach has successfully resolved similar contradictions in plant protein localization studies and provides a framework for reconciling apparently conflicting data .
For optimal ChIP protocol using At5g08680 antibodies:
Crosslinking and chromatin preparation:
Crosslink plant tissue with 1% formaldehyde for 10 minutes
Quench with 0.125 M glycine for 5 minutes
Homogenize in extraction buffer (50 mM HEPES pH 7.5, 150 mM NaCl, 1 mM EDTA, 1% Triton X-100, 0.1% sodium deoxycholate, protease inhibitors)
Sonicate to generate 200-500 bp fragments
Immunoprecipitation:
Pre-clear chromatin with protein A/G beads for 1 hour at 4°C
Incubate with 2-5 μg of At5g08680 antibody overnight at 4°C
Add protein A/G beads and incubate for 2 hours
Wash with increasingly stringent buffers
DNA recovery and analysis:
Reverse crosslinks at 65°C for 6 hours
Treat with RNase A and Proteinase K
Purify DNA using phenol-chloroform extraction or commercial kits
Analyze by qPCR or sequencing
Controls:
Input chromatin (non-immunoprecipitated)
IgG control (non-specific antibody)
Positive control (known target gene)
Negative control (non-target region)
This protocol has been optimized to minimize background while maximizing signal-to-noise ratio for plant transcription factor studies .
The development of a quantitative ELISA for At5g08680 protein detection requires:
Plate preparation:
Coat 96-well plates with capture antibody (1-5 μg/mL) in carbonate buffer pH 9.6
Incubate overnight at 4°C
Wash with PBST (PBS + 0.05% Tween-20)
Block with 1-5% BSA or non-fat milk for 1 hour at 37°C
Sample preparation:
Extract plant tissues in optimized buffer (50 mM Tris-HCl pH 7.5, 150 mM NaCl, 0.1% Triton X-100, protease inhibitors)
Clarify by centrifugation (14,000×g, 10 minutes, 4°C)
Prepare serial dilutions of purified At5g08680 protein as standards
Detection system:
Incubate samples and standards for 30 minutes at 37°C
Wash 3× with PBST
Add HRP-conjugated detection antibody (1:1000-1:5000)
Incubate for 30 minutes at 37°C
Wash 5× with PBST
Add TMB substrate and incubate for 15 minutes in darkness
Stop reaction with 2M H₂SO₄
Read absorbance at 450 nm
Data analysis:
Generate standard curve using 4-parameter logistic regression
Calculate EC₅₀ values for quantitative comparisons
Run all samples in triplicate to ensure reproducibility
This methodology provides detection sensitivity in the nanogram range with high specificity when optimized properly .
A comprehensive characterization of At5g08680 antibody properties requires multiple complementary approaches:
| Technique | Methodology | Data Generated |
|---|---|---|
| Surface Plasmon Resonance | Sensor chip immobilization, serial dilutions of antibody (30 μL/min flow rate), 100s baseline acquisition | kon, koff, and Kd values |
| ELISA | Serial antibody dilutions (0.01-10 μg/mL), 50 μg/mL antigen coating | EC₅₀, binding curves |
| Bio-Layer Interferometry | Antigen immobilization on biosensors, antibody association/dissociation | Real-time binding kinetics |
| Isothermal Titration Calorimetry | Direct measurement of binding thermodynamics | ΔH, ΔS, and Kd values |
| Cross-reactivity Testing | ELISA or Western blot against related proteins | Specificity profile |
For most accurate characterization, combine these approaches and determine consensus values. SPR analysis has demonstrated particular utility by allowing determination of association/dissociation constants that predict in vivo efficacy. Proper affinity characterization enables selection of the most suitable antibodies for specific applications .
To systematically troubleshoot non-specific binding:
Optimization of blocking agents:
Test multiple blocking agents (BSA, non-fat milk, casein, commercial blockers)
Determine optimal concentration (1-5%)
Evaluate blocking time (1-16 hours)
Buffer optimization:
Increase detergent concentration (0.05-0.5% Tween-20)
Add competing proteins (0.1-1% BSA in wash/incubation buffers)
Test different ionic strengths (100-500 mM NaCl)
Antibody optimization:
Pre-absorb antibody with plant extract from knockout lines
Purify antibody using affinity chromatography against the specific epitope
Optimize antibody concentration through titration experiments
Sample preparation modifications:
Add protease inhibitors to prevent degradation products
Optimize extraction buffer composition
Pre-clear samples with Protein A/G beads
Implementation of these approaches in systematic fashion can significantly reduce background while maintaining specific signal detection, as demonstrated in similar plant protein studies where background was reduced by >80% following optimization .
For robust statistical analysis of antibody-based experimental data:
For dichotomization of antibody response data:
Implement optimal cut-off determination by maximizing chi-squared statistics
Apply Benjamini-Yekutieli procedure to control false discovery rate (FDR 5%)
Use contingency table analysis for comparing experimental groups
For continuous response data:
Apply Box-Cox transformations to normalize distributions (λ range: -4 to 4)
Implement parametric tests (t-tests, ANOVA) for normally distributed data
Use non-parametric alternatives (Mann-Whitney, Kruskal-Wallis) when normality cannot be achieved
For predictive model building:
Implement Super-Learner approach combining multiple classifiers:
Logistic regression models with main effects
Random Forest algorithms
Linear/quadratic discriminant analysis
Gradient boosting methods
Evaluate model performance using AUC metrics with 95% confidence intervals
For multivariate correlation analysis:
Calculate Spearman's correlation coefficients between antibody responses
Apply hierarchical clustering to identify patterns
Implement dimension reduction techniques (PCA, t-SNE) for visualization
These statistical approaches have demonstrated superior performance in antibody-based studies, with AUC improvements from 0.68 to 0.80 in similar experimental systems .
A comprehensive control strategy for antibody experiments with transgenic Arabidopsis should include:
Genetic controls:
Wild-type Col-0 (positive control)
T-DNA insertion or CRISPR knockout of At5g08680 (negative control)
Complementation lines (rescue control)
Overexpression lines (high expression control)
Tagged protein lines (epitope validation)
Technical controls:
Secondary antibody only (background control)
Pre-immune serum (non-specific binding control)
Peptide competition (epitope specificity control)
Immunoprecipitation with non-relevant antibody (procedure control)
Experimental design considerations:
Include biological replicates (minimum n=3)
Use multiple independent transgenic lines for each construct
Implement randomization and blinding where possible
Include developmental stage controls for developmental regulators
Validation approaches:
Orthogonal detection methods (RT-qPCR, RNA-seq, proteomics)
Multiple antibodies targeting different epitopes
Different visualization methods (Western blot, immunofluorescence)
This multi-layered control strategy significantly reduces the risk of misinterpretation and provides robust validation of experimental findings .
To leverage At5g08680 antibodies for protein interaction studies, implement a multi-modal approach:
Antibody-based proximity labeling:
Conjugate At5g08680 antibody to promiscuous biotin ligase (BioID2)
Introduce into plant cells via protein delivery methods
Identify biotinylated proteins by streptavidin pulldown and mass spectrometry
Validate interactions through reciprocal Co-IP experiments
Advanced co-immunoprecipitation approaches:
Perform tandem affinity purification using At5g08680 antibody
Implement crosslinking-assisted immunoprecipitation for transient interactions
Use native versus denaturing conditions to distinguish direct and indirect interactions
Analyze by quantitative mass spectrometry with SILAC or TMT labeling
In situ interaction detection:
Proximity ligation assay (PLA) using At5g08680 antibody and antibodies against candidate interactors
Förster resonance energy transfer (FRET) using fluorophore-conjugated antibodies
BiFC validation of identified interactions
Network analysis:
Integrate data using statistical algorithms to filter low-confidence interactions
Apply machine learning approaches to predict additional interaction partners
Validate hub proteins through genetic and biochemical approaches
This integrated approach overcomes limitations of individual methods and has successfully identified previously unknown interactions in comparable plant signaling studies .
For optimal application of At5g08680 antibodies in chromatin research:
ChIP-seq protocol optimization:
Crosslink tissues with 1% formaldehyde (10 minutes)
Sonicate to generate 200-300 bp fragments (verified by Bioanalyzer)
Use 2-5 μg antibody per 25 μg chromatin
Include input, IgG, and positive controls
Prepare libraries using low-input methods for limited material
Sequence with minimum 20 million reads per sample
CUT&RUN or CUT&Tag adaptations:
Attach nuclei to ConA beads
Incubate with At5g08680 antibody (1:100 dilution)
Add pA-MNase or pA-Tn5
Release and prepare fragments for sequencing
This approach requires 10× less material than ChIP
Combinatorial approaches:
ChIP-reChIP for co-occupancy studies
ChIP-MS for identifying chromatin-associated protein complexes
ChIP-bisulfite sequencing for epigenetic correlation
Data analysis considerations:
Use MACS2 with plant-optimized parameters for peak calling
Implement IDR analysis for replicate consistency
Correlate binding with gene expression data
Perform motif analysis for co-regulatory factors
These methodologies have successfully elucidated the chromatin functions of plant regulatory proteins with sensitivity and specificity superior to traditional approaches .
To develop trispecific antibodies for studying At5g08680 in multiple cellular compartments:
Design strategy:
Engineer constructs in DVD-Ig format with full IgG1 antibody backbone
Select complementary scFvs targeting:
At5g08680 protein
Compartment-specific marker protein
Interacting protein of interest
Connect domains using GGGGSGGGGS linkers
Expression and purification:
Clone heavy and light chain sequences into suitable vectors
Co-transfect into HEK293F cells with 1:1.5 molar ratio
Culture in SMM 293-TII medium at 310K and 5% CO₂
Harvest supernatant after 5 days
Purify via Protein A and size-exclusion chromatography
Validation assays:
ELISA binding to individual antigens
Surface plasmon resonance for binding kinetics
Immunofluorescence to confirm compartment specificity
Co-localization analysis with known markers
Application in plant systems:
Protein transfection methods for live-cell applications
Fixed-cell imaging for spatial organization studies
Pulldown assays for compartment-specific interactome analysis
This trispecific approach enables simultaneous tracking of At5g08680 across multiple compartments and has demonstrated superior sensitivity compared to conventional antibodies in similar systems with expected yields of 5-10 mg/liter .