The EIF1AX antibody is a polyclonal or monoclonal immunoglobulin developed to bind specifically to the EIF1AX protein. Two widely used versions are available:
| Antibody Catalog # | Host/Isotype | Reactivity | Applications |
|---|---|---|---|
| [14654-1-AP] | Rabbit/IgG | Human | WB, IF/ICC, ELISA |
| [11649-2-AP] | Rabbit/IgG | Human, Mouse, Rat | WB, IHC, IF/ICC, ELISA |
Both antibodies target the 16 kDa EIF1AX protein, with [11649-2-AP] exhibiting broader cross-reactivity. The immunogen for [11649-2-AP] is an EIF1AX fusion protein (Ag2248), ensuring specificity for the RNA-binding domain of the target protein .
The antibody is employed in diverse experimental settings:
Western Blotting (WB): Detects EIF1AX in lysates from tumor cell lines (e.g., HepG2, PC-3) .
Immunofluorescence (IF/ICC): Localizes EIF1AX in subcellular compartments, such as the cytoplasm and nucleus .
Immunohistochemistry (IHC): Identifies EIF1AX expression in tissue sections, aiding cancer diagnostics .
Thyroid Cancer: The antibody has been pivotal in identifying EIF1AX mutations in papillary thyroid carcinoma (PTC) and anaplastic thyroid carcinoma (ATC) . Mutations at the A113splice site disrupt exon 6 splicing, producing truncated proteins that stabilize the PIC and enhance translation .
Breast Cancer: Overexpression of EIF1AX correlates with increased cell proliferation and tumor growth, mediated by transcriptional repression of the cell-cycle inhibitor p21 .
RAS Co-occurrence: In advanced thyroid cancers, EIF1AX mutations frequently co-occur with RAS mutations, synergizing to activate mTOR signaling and promote tumorigenesis .
Protein Synthesis: Mutant EIF1AX isoforms (e.g., c'spl, t'spl) exhibit enhanced binding to ternary complex (TC) components, increasing nascent protein synthesis rates .
The antibody’s ability to detect EIF1AX mutations has implications for:
EIF1AX (eukaryotic translation initiation factor 1A, X-linked) is an essential component of the translation pre-initiation complex (PIC). It plays critical roles in protein biosynthesis by:
Enhancing ribosome dissociation into subunits
Stabilizing the binding of initiator Met-tRNA(I) to 40S ribosomal subunits
The protein has an unblocked N-terminal proline consistent with the general pattern of eukaryotic proteins. Structurally, EIF1AX has important functional domains including the N-terminal tail (NTT) and C-terminal tail (CTT), which interact with other translation initiation components .
EIF1AX antibodies have been validated for multiple applications with specific dilution recommendations:
| Application | Validated Dilutions | Positive Detection Systems |
|---|---|---|
| Western Blot (WB) | 1:500-1:1000 | HepG2, A375, HeLa, PC-3, HEK-293T, Jurkat cells |
| Immunofluorescence (IF)/ICC | 1:50-1:500 or 1:200-1:800* | HepG2, HeLa cells |
| Immunohistochemistry (IHC) | 1:20-1:200 | Human gliomas tissue |
| ELISA | Varies by manufacturer | Human samples |
*Dilution varies by specific antibody product
Note: It is recommended to titrate the antibody in each testing system to obtain optimal results, as detection sensitivity can be sample-dependent .
For successful detection of EIF1AX in tumor tissues:
Immunohistochemistry protocol highlights:
Antigen retrieval: Use TE buffer pH 9.0 (recommended) or alternatively citrate buffer pH 6.0
Dilution range: 1:20-1:200
Detection systems: Both DAB and fluorescent secondary antibodies have been validated
Positive controls: Human gliomas tissue demonstrates reliable reactivity
When studying EIF1AX in cancer research, consider that expression patterns differ between cancer types. For example, in breast cancer, both nuclear and cytoplasmic staining is observed, with stronger EIF1AX staining in both compartments compared to normal mammary epithelial cells .
EIF1AX has emerging roles in multiple cancer types, making it an important research target:
Breast cancer:
EIF1AX promotes breast cancer proliferation by facilitating G1/S cell cycle transition
Mechanistically inhibits p21 transcription in a p53-independent manner
Expression levels in breast cancer correlate with histological grades and patient survival
Detection method: Combined qRT-PCR and IHC showed EIF1AX is significantly upregulated in carcinoma tissues compared to adjacent normal tissues
Thyroid cancer:
EIF1AX mutations (particularly A113splice) cooperate with RAS mutations to drive thyroid tumorigenesis
Detection of EIF1AX-c'spl variant has diagnostic significance
EIF1AX mutants show higher affinity to components of the translation PIC and increase protein synthesis
Endometrial carcinoma:
Cytoplasmic EIF1AX expression shows gradual increase from normal tissue through hyperplasia to carcinoma
Nuclear EIF1AX expression follows opposite pattern
Cytoplasmic expression correlates with histologic type, FIGO grade, stage, infiltration depth, Ki67 index, and recurrence-free survival
To ensure experimental rigor, validate antibody specificity through:
Western blot validation:
Genetic validation:
Cross-reactivity assessment:
Co-immunoprecipitation (Co-IP) studies have revealed important insights about EIF1AX interactions:
Experimental approach:
Express HA-tagged EIF1AX (wild-type or mutants) in appropriate cell lines
Immunoprecipitate using anti-HA antibody
Analyze pull-down of translation initiation components by western blot
Key findings from this methodology:
EIF1AX interacts with EIF2α, a component of the ternary complex (TC)
EIF1AX mutants (particularly G8R, G9R, and c'spl) show increased affinity for EIF5
These interactions suggest EIF1AX mutants result in a more stable 43S ribosomal complex
This methodology has revealed that EIF1AX mutations can alter translation dynamics
EIF1AX shows interesting subcellular localization patterns relevant to disease progression:
Methodological considerations:
Subcellular fractionation:
Separate nuclear and cytoplasmic fractions before western blotting
Use appropriate markers (GAPDH for cytoplasm, Lamin B for nucleus)
Immunofluorescence optimization:
Dilution: 1:50-1:500 (specific to antibody product)
Fixation: 4% paraformaldehyde recommended
Permeabilization: 0.1% Triton X-100
Include DAPI or other nuclear counterstain
Quantification approaches:
Nuclear-to-cytoplasmic ratio measurement
Correlation with disease progression markers
Research significance:
In endometrial carcinoma, cytoplasmic EIF1AX expression increases while nuclear expression decreases during disease progression from normal tissue to carcinoma. Cytoplasmic transport appears to be regulated by exportin 1 (XPO1), and targeting this nucleocytoplasmic transport may offer therapeutic approaches .
EIF1AX mutations cluster in two main regions:
N-terminal tail (NTT) - first 15 amino acids (common in uveal melanoma)
Splice acceptor site upstream of exon 6 (A113splice) - common in thyroid cancer
Methodological approaches:
Mutation-specific antibodies: Limited commercial availability; custom antibodies may be needed
Expression systems:
Transfect cells with wild-type or mutant EIF1AX constructs
Use antibody against tag (HA, FLAG, etc.) to detect and compare function
Functional readouts:
Research has shown that EIF1AX mutations can alter interactions with translation machinery components, particularly increasing affinity for EIF5 and stabilizing the pre-initiation complex .
EIF1AX has been shown to transcriptionally repress p21 in a p53-independent manner, promoting cell cycle progression and cancer cell proliferation .
Experimental design approach:
ChIP assays:
Luciferase assays:
Rescue experiments:
Recommended controls for rigorous EIF1AX research:
Cell line controls:
Tissue controls:
Expression controls:
Cellular compartment markers:
Based on current research findings, EIF1AX has potential as a diagnostic or prognostic marker:
Breast cancer: EIF1AX expression correlates with histological grades and survival rates
Thyroid cancer: EIF1AX mutations (particularly A113splice) strongly co-occur with RAS mutations (p=3.15×10E-13) in advanced cases
Endometrial carcinoma: Cytoplasmic EIF1AX expression correlates with FIGO grade, stage, and recurrence-free survival
Potential development approaches:
IHC-based scoring systems combining nuclear/cytoplasmic ratios
Mutation-specific antibodies targeting common cancer-associated variants
Integration with other cancer biomarkers for improved prognostic accuracy
EIF1AX modulates translation of specific mRNAs, particularly those with regulatory elements:
Methodological approaches:
Ribosome profiling:
Compare translation efficiency in cells with wild-type vs. mutant EIF1AX
Focus on mRNAs with complex 5'UTRs or upstream open reading frames (uORFs)
Translation reporter assays:
Stress response studies:
Understanding these mechanisms could reveal how EIF1AX mutations contribute to cancer cell survival under stress conditions, potentially identifying therapeutic vulnerabilities.