Guanine nucleotide-binding protein subunit alpha-13 (GNA13) is a G-protein subunit critical in RhoA-mediated signaling pathways, influencing processes like cytoskeletal reorganization, cell migration, and cancer progression . The GNA13 antibody is a rabbit recombinant monoclonal antibody (EPR5436, ab128900) or mouse monoclonal antibody (67188-1-Ig) designed to detect and study GNA13 in human, mouse, rat, and pig models . It is widely used in Western blotting (WB), immunohistochemistry (IHC), and co-immunoprecipitation (CoIP) to explore its role in signaling and disease mechanisms.
GNA13 activates RhoA by binding to Rho guanine nucleotide exchange factors (RhoGEFs), such as ARHGEF1/p115RhoGEF, which regulate transcription factor AP-1 and promote tumor cell invasion . In cancer models, GNA13-dependent RhoA/ROCK signaling enhances metastasis, making it a therapeutic target .
The Abcam GNA13 antibody demonstrates specificity by detecting a distinct 45 kDa band in wild-type HeLa lysates, absent in GNA13 knockout lysates . This validation ensures reliable detection in WB and IHC assays.
IHC studies reveal GNA13 expression in human bladder carcinoma, kidney, and rodent stomach tissues . The antibody’s utility in formalin-fixed paraffin-embedded (FFPE) sections highlights its versatility in histopathological studies.
Protocol:
Protocol:
Proteintech’s 67188-1-Ig is validated for CoIP, enabling studies on GNA13-protein interactions in signaling complexes .
Perform serial dilution tests (1:100-1:2000) in both techniques
Include positive controls:
HEK293 cells overexpressing GASA13 for Western blot
Human placental tissue sections for IHC
Negative controls must use knockout cell lines or peptide-blocked antibody samples
| Parameter | Western Blot | Immunohistochemistry |
|---|---|---|
| Fixation | N/A | 4% PFA vs. methanol effects |
| Epitope Access | Denaturation-dependent | Antigen retrieval required |
| Quantification | Densitometry | H-Score analysis |
Cross-validate using mass spectrometry (LC-MS/MS) for antibody specificity confirmation .
Technical Reconciliation:
Compare subcellular fractionation protocols (differential centrifugation vs. sucrose gradients)
Standardize lysis buffers across labs (RIPA vs. NP-40 formulations)
Biological Context Analysis:
Map findings against developmental stages using time-course experiments
Analyze tissue-specific splice variants via RT-PCR
Advanced Approach
Implement super-resolution microscopy (STED/PALM) with dual-labeling for:
Genotypic:
CRISPR-Cas9 knockout lines
RNAi silencing efficiency ≥80%
Phenotypic:
Rosette diameter measurements (Col-0 vs. mutants)
Flowering time tracking under LD/SD conditions
Phylogenetic Alignment:
Compare epitope region across 12 angiosperm species
Synthesize divergent peptide sequences (>3aa differences)
Validation Matrix:
| Species | Expected Reactivity | Test Method |
|---|---|---|
| A. thaliana | Strong (positive) | Dot blot |
| O. sativa | Moderate | ELISA (OD450≥1.2) |
| Z. mays | Weak/Negative | Immunoprecipitation |
Advanced Application
Combine with molecular dynamics simulations to predict antibody-antigen binding affinity variations .
Housekeeper Selection: GeNorm analysis of 12 candidate genes
Normalization Formula:
Advanced Considerations
Implement quantile normalization with cross-platform adjustment for:
RNA-seq FPKM values
Microarray fluorescence intensities
qPCR ΔΔCt calculations
Include batch effect correction using ComBat algorithm for multi-experiment studies .
Primary: Co-IP with known interactors (DELLA proteins)
Secondary: BioID proximity labeling + mass spec
Tertiary: FRET efficiency ≥25% in planta
| Artifact Source | Mitigation Strategy |
|---|---|
| Non-specific binding | Increase stringency (500mM NaCl wash) |
| Epitope masking | Alternative cleavage (TEV vs. Thrombin) |
| Transient interactions | Kinetic measurements (SPR analysis) |
Confirm findings using orthogonal methods like Y2H and bimolecular fluorescence complementation .
Staining Index Calculation:
Intensity: 0-3 scale (negative to strong)
Positivity: % cells above threshold
Advanced Imaging Analysis
Implement machine learning segmentation using Trainable Weka:
Train classifier on 500+ annotated regions
Validate against manual scoring (Cohen’s κ ≥0.85)
Experimental Design
Phase 1: Hormonal Crosstalk Analysis
Treatment Matrix:
| Hormone | Concentration | Duration |
|---|---|---|
| GA3 | 10μM | 6h |
| ABA | 100μM | 24h |
| JA | 50μM | 12h |
Phase 2: ROS Localization Mapping
Use HyPer sensor transgenic lines
Capture time-lapse images at 5-min intervals
Advanced Integration
Apply Boolean network modeling to predict regulatory nodes in growth-stress tradeoffs .