FAM43A Antibody

What is FAM43A and why is it important in research?

FAM43A (family with sequence similarity 43, member A) is a protein involved in cellular function and signaling pathways. Recent research has identified FAM43A as a CHK2-dependent early responder to mitochondrial DNA depletion that performs a checkpoint-like function in limiting mitochondrial biogenesis and turnover . Additionally, FAM43A has been identified as one of six genes in a prediction model for triple negative breast cancer recurrence . The growing importance of this protein in cancer research and mitochondrial biology makes antibodies against FAM43A valuable tools for investigating its expression and function in various cellular contexts.

What are the common applications for FAM43A antibodies?

FAM43A antibodies are primarily used in the following research applications:

Researchers should validate the antibody in their specific experimental setup as expression patterns may vary between tissues and species.

What tissues express FAM43A and how should sample preparation be optimized?

FAM43A expression has been detected in multiple tissues including brain, skeletal muscle, and heart. In zebrafish, FAM43A (fam43a) is expressed in blood vessels, nervous system, optic primordium, optic vesicle, and solid lens vesicle . For optimal sample preparation:

• For protein extraction: Use standard RIPA buffer with protease inhibitors

• For paraffin-embedded tissues: Heat-induced antigen retrieval methods (citrate buffer pH 6.0) are recommended

• For immunofluorescence: 4% paraformaldehyde fixation followed by permeabilization with 0.1-0.3% Triton X-100

For Western blot applications, mouse brain and skeletal muscle tissues have been successfully used to detect FAM43A at approximately 46 kDa .

How does FAM43A function in mitochondrial biology and what experimental approaches are recommended?

Recent research published in the Journal of Cell Biology (2025) has revealed that FAM43A plays a critical role in coordinating mitochondrial DNA (mtDNA) replication and mitochondrial biogenesis . The study identified FAM43A as a CHK2-dependent early responder to mtDNA depletion. For researchers investigating mitochondrial functions of FAM43A:

• Recommended approach: Use mtDNA-depleted cell models (e.g., IMR90 cells) treated with mtDNA depletion agents

• Key measurements: Monitor mtDNA copy number, OXPHOS activity, and mitochondrial mass

• Protein interactions: Investigate FAM43A's relationship with CHK2 and p53R2 form of ribonucleotide reductase

• Knockdown studies: FAM43A depletion has been shown to activate mitochondrial biogenesis programs

This research suggests FAM43A performs a checkpoint-like function to limit mitochondrial biogenesis under conditions of mtDNA depletion or replication stress .

What is the significance of FAM43A in cancer research and how should experimental approaches be designed?

FAM43A has been identified as part of a six-gene prediction model for triple negative breast cancer (TNBC) recurrence in Taiwanese patients . This model, which includes SLC22A23, PRKAG3, DPEP3, MORC2, GRB7, and FAM43A, demonstrated 91.7% accuracy in predicting cancer recurrence. For cancer researchers studying FAM43A:

• Expression analysis: Compare FAM43A expression between normal and cancerous tissues

• Prognostic studies: Consider FAM43A expression in conjunction with other genes in the prediction model

• Population considerations: Evidence suggests ethnic differences in gene expression patterns, so include appropriate demographic controls

• Pathway analysis: Two pathways significantly associated with TNBC recurrence were cAMP-mediated signaling and ephrin receptor signaling

The research indicates that FAM43A may have different prognostic significance in Asian versus Caucasian populations, suggesting the importance of controlling for ethnic background in cancer studies involving this gene.

What are the key differences between polyclonal and monoclonal FAM43A antibodies and their optimal applications?

Most commercially available FAM43A antibodies are polyclonal antibodies raised in rabbits. These differences impact research applications:

For most research applications involving FAM43A, polyclonal antibodies provide good detection across multiple techniques, but researchers should validate specificity using appropriate controls.

How can researchers optimize Western blot protocols for detecting FAM43A?

For successful Western blot detection of FAM43A:

• Lysate preparation:

  • Use RIPA buffer with protease inhibitors

  • For brain and skeletal muscle tissues, additional mechanical disruption may be required

• Gel electrophoresis and transfer:

  • 10-12% SDS-PAGE gels are appropriate for the 46 kDa FAM43A protein

  • Standard PVDF membranes (0.45 μm) are suitable for transfer

• Blocking and antibody incubation:

  • Block with 5% non-fat dry milk or BSA in TBST

  • Primary antibody dilution: 1:500-1:5000 depending on antibody lot

  • Incubate overnight at 4°C for optimal results

  • Secondary antibody: Anti-rabbit IgG at 1:50000 dilution

• Detection and troubleshooting:

  • Expected band size: 46 kDa

  • If multiple bands appear, optimize antibody concentration and washing steps

  • Positive controls: Mouse brain and skeletal muscle tissue lysates

What are the critical considerations for immunohistochemistry (IHC) applications of FAM43A antibodies?

For optimal immunohistochemistry results with FAM43A antibodies:

• Tissue preparation:

  • Formalin-fixed paraffin-embedded (FFPE) sections at 4-6 μm thickness

  • Heat-induced epitope retrieval (HIER) using citrate buffer (pH 6.0)

• Antibody incubation:

  • Recommended dilution range: 1:20-1:200 or 1:200-1:500

  • Overnight incubation at 4°C typically yields best results

  • Use appropriate blocking serum to reduce background staining

• Detection systems:

  • HRP/DAB detection systems work well for FAM43A visualization

  • For fluorescent detection, secondary antibodies conjugated with bright fluorophores are recommended

• Controls and validation:

  • Include human heart tissue as a positive control

  • Perform negative controls (omitting primary antibody)

  • Consider peptide competition assays to confirm specificity

• Signal interpretation:

  • Document subcellular localization to help interpret biological function

  • Compare staining patterns with published literature

What experimental controls are essential when working with FAM43A antibodies?

When designing experiments involving FAM43A antibodies, include these essential controls:

• Positive tissue controls:

  • Mouse brain and skeletal muscle tissue for Western blot

  • Human heart tissue for immunohistochemistry

  • Tissues known to express FAM43A from published literature

• Negative controls:

  • Secondary antibody only (omitting primary antibody)

  • Tissues/cells known not to express FAM43A

  • Isotype controls (non-specific IgG from same species)

• Validation controls:

  • Recombinant FAM43A protein for specificity testing

  • FAM43A knockdown or knockout cells/tissues

  • Peptide competition assays using the immunogenic peptide

• Expression controls:

  • Comparison with RNA expression data (e.g., RT-PCR)

  • Comparison with published expression patterns

These controls help ensure the specificity of antibody binding and validate experimental findings.

How should researchers approach FAM43A expression analysis in cancer studies?

For cancer researchers investigating FAM43A expression:

• Cohort selection:

  • Consider ethnic background variations, as FAM43A expression patterns differ between Asian and Caucasian populations

  • Include appropriate matched controls (adjacent normal tissue)

  • Collect comprehensive clinical data for correlation analyses

• Multi-omics approach:

  • Combine protein detection (using FAM43A antibodies) with mRNA expression analysis

  • Consider evaluation of all six genes in the TNBC prediction model: SLC22A23, PRKAG3, DPEP3, MORC2, GRB7, and FAM43A

  • Analyze pathway activation (cAMP-mediated and ephrin receptor signaling)

• Analysis methods:

  • Quantitative scoring of tissue microarrays

  • Cox proportional hazards models for survival analysis

  • Machine learning approaches for prediction model validation

  • Pathway enrichment analysis

• Validation strategies:

  • Independent cohort validation

  • Cross-validation using leave-one-out support vector regression

  • Comparison with established prognostic markers

This approach allows for robust evaluation of FAM43A's role in cancer progression and prognosis.

What methodological approaches are recommended for studying FAM43A's role in mitochondrial biology?

Based on recent research , investigators studying FAM43A's mitochondrial functions should consider:

• Cell models:

  • IMR90 cells (shown to maintain OXPHOS after mtDNA depletion)

  • mtDNA-depleted cell lines created using ethidium bromide or other depletion agents

  • FAM43A knockdown and overexpression models

• Key measurements:

  • mtDNA copy number quantification (qPCR)

  • Mitochondrial mass assessment (MitoTracker staining, porin/VDAC quantification)

  • OXPHOS activity (Seahorse analysis, complex activity assays)

  • CHK2 phosphorylation and activity

  • p53R2 ribonucleotide reductase expression and activity

• Experimental designs:

  • Time-course studies following mtDNA depletion

  • Rescue experiments with FAM43A re-expression

  • CHK2 inhibition studies

  • Interaction studies (co-immunoprecipitation, proximity ligation assays)

• Advanced approaches:

  • Live-cell imaging of mitochondrial dynamics

  • Mitochondrial proteomics before and after FAM43A manipulation

  • Metabolic flux analysis

These methodological approaches will help elucidate the checkpoint-like function of FAM43A in limiting mitochondrial biogenesis under conditions of mtDNA depletion.

How might FAM43A antibodies be used to investigate potential therapeutic targets?

As understanding of FAM43A function expands, researchers can use FAM43A antibodies to:

• Cancer therapeutic strategies:

  • Evaluate FAM43A expression changes in response to chemotherapy or targeted therapies

  • Monitor FAM43A as a potential biomarker of treatment response in triple negative breast cancer

  • Investigate correlation between FAM43A expression and drug resistance

• Mitochondrial disease approaches:

  • Assess FAM43A's role in mitochondrial diseases characterized by mtDNA depletion syndromes

  • Investigate whether FAM43A modulation could rescue mitochondrial dysfunction

  • Explore the CHK2-FAM43A-p53R2 axis as a therapeutic target

• Screening applications:

  • Develop high-content screening assays using FAM43A antibodies to identify compounds that modulate its expression or localization

  • Create reporter cell lines to monitor FAM43A dynamics in real-time

The growing understanding of FAM43A's role in mitochondrial biology and cancer provides multiple avenues for therapeutic exploration.

What are the considerations for investigating FAM43A in different model systems?

When studying FAM43A across different model systems:

• Species considerations:

  • Human and mouse FAM43A antibodies are most commonly available and validated

  • Zebrafish fam43a has been studied in developmental contexts

  • Sequence homology should be evaluated before cross-species antibody application

• Model selection:

  • Cell lines: IMR90 cells have been validated for mitochondrial studies

  • Animal models: Consider zebrafish for developmental studies

  • Patient-derived samples: Important for clinical correlation and validation

• Developmental studies:

  • In zebrafish, fam43a is expressed in blood vessels, nervous system, optic structures

  • Temporal expression patterns should be considered when designing developmental studies

• Technical adaptations:

  • Optimize antibody concentrations for each model system

  • Validate specificity in each species using appropriate controls

  • Consider fixation and sample preparation modifications for different tissues