BFSP1 encodes filensin, a 665-amino-acid protein that forms beaded filaments (BFs) with phakinin (CP49) in lens fiber cells . These filaments are unique to vertebrates and contribute to lens refractive properties and mechanical stability. Post-translational processing of BFSP1 generates C-terminal fragments (e.g., residues 434–548) that regulate calcium-sensitive AQP0 water permeability .
BFSP1 antibodies are available in monoclonal and polyclonal forms, validated across species (human, bovine, mouse) and applications (Western blot, immunohistochemistry, immunofluorescence).
| Supplier | Catalog # | Clonality | Host | Reactivity | Applications | Target Epitope/Immunogen |
|---|---|---|---|---|---|---|
| BosterBio | MA1041 | Monoclonal | Mouse | Human, Bovine | IHC, WB | Lens filament-enriched fraction |
| Proteintech | 17492-1-AP | Polyclonal | Rabbit | Human, Mouse | WB, IF/ICC, ELISA | Recombinant BFSP1 fusion protein |
| Abbexa | - | Polyclonal | Rabbit | Human, Mouse, Rat | WB | Recombinant BFSP1 fragment |
| Sigma-Aldrich | HPA042038 | Polyclonal | Rabbit | Human | IHC, IF | Synthetic peptide (C-terminal) |
Western Blot: BFSP1 antibodies detect bands at ~94 kDa (full-length) and smaller fragments (e.g., 53 kDa) resulting from caspase cleavage . For example, Proteintech’s 17492-1-AP identifies a 94 kDa band in mouse eye tissue .
Immunohistochemistry: BosterBio’s MA1041 shows strong reactivity in human and bovine lens plasma membrane-cytoskeleton complexes .
Enhanced Validation: Some antibodies (e.g., Sigma-Aldrich HPA042038) undergo siRNA knockdown and GFP-tagged protein validation to confirm specificity .
BFSP1 antibodies have elucidated:
Caspase-Mediated Processing: Caspase-2 cleaves BFSP1 at D433 and D549, producing fragments (e.g., 53 kDa) that alter AQP0 regulation . Mutagenesis studies (D433A/D549A) confirm these cleavage sites .
Membrane Binding: C-terminal fragments (residues 434–548) bind lens lipid membranes via an amphipathic helix, independent of AQP0 . Surface plasmon resonance (SPR) assays reveal a dissociation constant () of 0.8 µM for fragment 434–548 .
Cataractogenesis: BFSP1 mutations disrupt lens fiber cell architecture, linking BFSP1 dysfunction to cataracts .
Autoimmunity: Genome-wide studies associate BFSP1 loci with antiphospholipid antibody production, suggesting broader systemic roles .
| BFSP1 Construct | Calcium Response (AQP0 Pf) | Key Finding |
|---|---|---|
| Full-length BFSP1 | No change | Requires caspase cleavage for activity |
| 434–665 | Low in 1.8 mM Ca²⁺ | Partial retention of calcium sensitivity |
| 434–548 (wild-type) | No change | Disrupts calcium regulation |
| 434–548 (D433A mutant) | Restored response | Highlights caspase-2’s role in processing |
Beaded Filament Structural Protein 1 (BFSP1), also known as filensin, is a plasma membrane aquaporin 0 (AKP0/MIP)-related intermediate filament protein primarily expressed in the lens, functioning as a cellular skeletal protein . BFSP1 has gained significant research interest due to its identification as an independent risk factor for liver cancer, with high expression indicating poor prognosis in liver cancer patients . Recent studies have revealed BFSP1 as an m6A RNA methylation-associated gene in cancer that is closely related to carbohydrate catabolism and glycolysis . The gene is encoded by the BFSP1 gene (GeneID: 631) and has UniProt accession Q12934 . Research using BFSP1 antibodies has been critical in elucidating the protein's role in normal cellular function and in pathological conditions, particularly in cancer research where its expression patterns provide valuable prognostic information.
BFSP1 antibodies used in research typically have the following specifications:
| Parameter | Specification | Notes |
|---|---|---|
| Clonality | Polyclonal | More common for recognizing multiple epitopes |
| Host species | Rabbit | Provides good specificity and yield |
| Reactivity | Human | Species-specific targeting |
| Applications | ELISA, WB, IF/ICC | Multiple experimental platforms |
| Form | Liquid | Optimal for laboratory handling |
| Purification method | Antigen Affinity Chromatography | Ensures specificity |
| Isotype | IgG | Standard antibody class |
| Storage | -20°C, avoid freeze/thaw | Maintains antibody integrity |
| Buffer | PBS, pH 7.3, with 0.02% Sodium Azide and 50% Glycerol | Stabilizes the antibody |
These antibodies are typically generated using human BFSP1 as the immunogen and purified through antigen affinity chromatography to ensure high specificity . When selecting an antibody for research, it is crucial to consider the specific application requirements and verify that the antibody has been validated for your intended experimental techniques.
Optimization of BFSP1 antibodies varies depending on the experimental technique:
For Western Blotting:
Begin with a dilution range test (typically 1:500 to 1:2000) to determine optimal concentration
Include proper positive and negative controls, especially tissues/cells known to express BFSP1 (lens tissues as positive control)
Optimize blocking conditions (3-5% BSA or milk in TBST) to reduce background
Consider longer transfer times for this intermediate filament protein
Validation should include knockdown/knockout samples when possible
For Immunofluorescence/Immunocytochemistry:
Test fixation methods (4% paraformaldehyde typically works well)
Optimize permeabilization (0.1-0.5% Triton X-100)
For co-localization studies with TMOD4, carefully select compatible secondary antibodies to avoid cross-reactivity
Include DAPI staining to visualize nuclei and confirm cytoplasmic localization pattern of BFSP1
For ELISA:
Establish a standard curve using recombinant BFSP1 protein
Determine optimal coating concentration and antibody dilution
Validate assay sensitivity and specificity with known positive and negative samples
Each application requires specific optimization, and researchers should always determine optimal dilutions/concentrations based on their specific experimental conditions and sample types .
To maintain BFSP1 antibody integrity and performance:
Storage temperature: Store at -20°C in small aliquots to minimize freeze-thaw cycles
Avoid repeated freeze/thaw cycles which can lead to protein denaturation and loss of activity
When handling, keep the antibody on ice and return to storage promptly
Buffer composition: BFSP1 antibodies are typically formulated in PBS, pH 7.3, containing 0.02% Sodium Azide and 50% Glycerol for stability
For long-term storage (>1 year), consider keeping master aliquots at -80°C
Monitor expiration dates and perform validation tests periodically
When diluting working solutions, use high-quality, sterile buffers
Document all freeze-thaw cycles and observe for any precipitation or color changes that might indicate degradation
Proper storage and handling significantly impact experimental reproducibility and reliability. Creating multiple small-volume aliquots upon receipt minimizes the risk of contamination and degradation from repeated handling and temperature fluctuations.
BFSP1 has emerged as a significant factor in liver cancer progression through several mechanisms:
Expression patterns: BFSP1 is significantly upregulated in liver cancer tissues compared to adjacent normal tissues, with high expression correlating with poor prognosis
Impact on cancer cell metabolism: BFSP1 promotes aerobic glycolysis in liver cancer cells by:
Cellular mechanisms: BFSP1 overexpression promotes:
Molecular interactions: BFSP1 directly interacts with tropomodalin 4 (TMOD4) as confirmed by:
Regulatory mechanisms: BFSP1 is regulated through m6A RNA modification, with METTL3-mediated methylation enhancing BFSP1 mRNA stability in a YTHDF1-dependent manner
These findings suggest that BFSP1 functions as an oncogene in liver cancer, primarily by reprogramming cellular metabolism toward aerobic glycolysis (the Warburg effect) and promoting malignant phenotypes through its interaction with TMOD4.
To investigate the BFSP1-TMOD4 interaction in cancer research, the following techniques have proven effective:
Co-immunoprecipitation (Co-IP):
Immunofluorescence co-localization:
Use compatible primary antibodies (rabbit anti-BFSP1 and mouse anti-TMOD4, or vice versa)
Select non-cross-reactive secondary antibodies with distinct fluorophores
Perform high-resolution confocal microscopy to precisely determine subcellular co-localization patterns
Quantify co-localization using Pearson's correlation coefficient or Manders' overlap coefficient
GST pull-down assays:
Proximity Ligation Assay (PLA):
Provides visualization of protein interactions in situ with high sensitivity
Particularly useful for detecting transient or weak interactions
Functional validation approaches:
siRNA/shRNA knockdown of TMOD4 in BFSP1-overexpressing cells
Assess rescue effects on glycolytic phenotypes, invasion, and proliferation
Design truncation mutants to map interaction domains
When investigating this interaction, it's critical to examine both physical binding and functional consequences, particularly in the context of glycolytic reprogramming and cancer cell invasion.
Measuring and analyzing m6A modification of BFSP1 mRNA requires specialized techniques:
Methylated RNA Immunoprecipitation (MeRIP)-qPCR:
m6A site prediction and validation:
RNA stability assays:
Manipulation of m6A machinery:
Advanced technologies:
m6A-seq or MICLIP for transcriptome-wide m6A mapping
DART-seq for single-base resolution mapping of m6A sites
Nanopore direct RNA sequencing for real-time detection of m6A
When analyzing results, consider the dynamic nature of m6A modification and its context-dependent effects, particularly in cancer cells where methylation machinery may be dysregulated.
When using BFSP1 antibodies to study glycolytic metabolism in cancer, researchers should consider these important factors:
Experimental design considerations:
Include multiple glycolytic parameters beyond just BFSP1 expression:
Compare results across different cell lines to account for metabolic heterogeneity
Use both gain-of-function and loss-of-function approaches (BFSP1 overexpression and knockdown)
Technical considerations for BFSP1 antibody use:
Validate BFSP1 antibody specificity in metabolically relevant contexts
For subcellular localization studies, combine with glycolytic enzyme markers
When performing co-IP with BFSP1 antibodies, optimize lysis conditions to preserve metabolic enzyme interactions
Consider fixation impact on metabolic enzyme epitopes for immunofluorescence studies
Controls and validation:
Include metabolic inhibitors (2-DG, oligomycin) to confirm glycolytic dependence
Use siRNA/shRNA against BFSP1 as specificity controls
Compare results with established glycolytic regulators (HIF-1α, c-Myc)
Downstream analysis:
Mechanistic investigations:
By carefully addressing these considerations, researchers can more accurately characterize the role of BFSP1 in cancer metabolism and potentially identify new therapeutic targets.
METTL3-mediated m6A modifications regulate BFSP1 expression and function through a complex molecular mechanism:
m6A site distribution and recognition:
Regulatory pathway components:
Impact on BFSP1 mRNA stability:
Expression correlation in cancer:
Functional consequences:
In vivo validation:
This METTL3-YTHDF1-BFSP1 axis represents a critical m6A-dependent regulatory mechanism controlling cancer metabolism and progression, offering potential therapeutic targets for intervention.
Comprehensive validation of BFSP1 antibodies is crucial for reliable cancer research results:
Specificity validation:
Western blot analysis showing a single band at the expected molecular weight (~83 kDa for BFSP1)
Disappearance of signal after BFSP1 knockdown/knockout (critical negative control)
Comparison with alternative BFSP1 antibodies targeting different epitopes
Pre-adsorption tests with immunizing peptide
Application-specific validation:
For Western blotting: Linear range determination using serial dilutions of lysate
For immunofluorescence: Comparison of fixation methods and signal localization patterns
For immunoprecipitation: Verification that the antibody can pull down endogenous BFSP1 protein
Context-specific validation:
Functional validation:
Analytical validation:
Reproducibility testing across multiple experiments and lots
Sensitivity assessment through limit of detection determination
Comparison with orthogonal detection methods (e.g., mass spectrometry)
Documentation requirements:
Detailed recording of antibody source, catalog number, and lot
Standardized protocols for each application
Inclusion of all validation data in publications and reports
Optimizing protocols for detecting BFSP1 in different subcellular compartments requires careful attention to various experimental parameters:
Cell/tissue preparation techniques:
Fresh vs. fixed samples: BFSP1 detection may be impacted by fixation methods
Fixative selection: 4% paraformaldehyde for preserving protein epitopes
Permeabilization: Digitonin for plasma membrane (mild), Triton X-100 for cytoplasmic (moderate), or methanol for nuclear (strong) permeabilization
Antigen retrieval: Consider heat-induced or enzymatic methods for tissue sections
Subcellular fractionation approaches:
Differential centrifugation to separate cytoplasmic, membrane, and nuclear fractions
Density gradient centrifugation for more refined separation
Commercial fractionation kits optimized for intermediate filament proteins
Verification of fraction purity with compartment-specific markers
Immunofluorescence optimization:
Co-staining with organelle markers:
Cytoplasm: β-tubulin or phalloidin (actin)
Membranes: Na⁺/K⁺-ATPase
Nucleus: DAPI or Hoechst
High-resolution imaging techniques:
Confocal microscopy for 3D localization
Super-resolution techniques (STED, STORM) for detailed distribution patterns
Z-stack acquisition and 3D reconstruction for comprehensive localization assessment
Protocol modifications for different compartments:
Cytoplasmic BFSP1: Standard protocols usually sufficient; consider shorter fixation times
Membrane-associated BFSP1: Avoid harsh detergents; use gentler permeabilization
Nuclear BFSP1: May require stronger permeabilization and nuclear envelope disruption
Validation approaches:
Subcellular markers co-localization analysis
Biochemical validation through fractionation followed by Western blotting
Comparison with established localization patterns in relevant cell types
Based on published research, BFSP1 primarily localizes to the cytoplasm in liver cancer cells, where it co-localizes with TMOD4 . This localization pattern is consistent with its role in cytoskeletal organization and cellular metabolism.
When encountering contradictory data in BFSP1 expression studies, researchers should implement a systematic troubleshooting approach:
Technical reconciliation strategies:
Antibody comparison: Test multiple antibodies targeting different BFSP1 epitopes
Method validation: Verify results using orthogonal techniques (qPCR, Western blot, immunofluorescence)
Sample preparation standardization: Establish consistent protocols for all comparative analyses
Quantification method evaluation: Compare densitometry, fluorescence intensity, and automated image analysis
Biological variation considerations:
Cell line heterogeneity: Different cancer cell lines may have variable BFSP1 expression patterns
Tissue microenvironment influences: Consider effects of tumor microenvironment on expression
Isoform-specific expression: Check for differential expression of BFSP1 splice variants
Post-translational modifications: Assess impact of phosphorylation, ubiquitination, etc.
Experimental design improvements:
Increase biological and technical replicates
Include appropriate positive and negative controls
Implement blinding in analysis to reduce bias
Use standardized reporting guidelines (e.g., MIQE for qPCR)
Advanced resolution techniques:
Single-cell analysis to address cellular heterogeneity
Temporal expression studies to capture dynamic changes
Correlation with functional readouts (glycolysis, invasion)
Multi-omics integration (transcriptomics, proteomics, metabolomics)
Statistical approaches:
Power analysis to ensure adequate sample size
Appropriate statistical tests based on data distribution
Multiple testing correction for high-dimensional data
Meta-analysis of published data for broader context
Regulatory mechanism investigation:
When reporting contradictory findings, transparently discuss potential sources of variation and explicitly describe reconciliation attempts to advance understanding of BFSP1 biology in cancer.
BFSP1 antibodies offer several valuable applications in clinical cancer research:
Prognostic biomarker development:
Diagnostic applications:
Differential BFSP1 expression analysis between tumor and adjacent normal tissues
Assessment of BFSP1 expression in circulating tumor cells or liquid biopsies
Correlation of BFSP1 levels with tumor stage and grade
Integration with other diagnostic markers for improved accuracy
Therapeutic target evaluation:
Monitoring BFSP1 expression changes in response to therapy
Identification of patient subgroups likely to benefit from metabolic-targeted therapies
Evaluation of combination therapy effects on BFSP1 and glycolytic pathways
Development of companion diagnostics for metabolism-targeting drugs
Mechanistic investigations in clinical samples:
Protocol considerations for clinical specimens:
Optimize fixation protocols for preserved clinical samples
Validate antibody performance in FFPE tissues
Implement automated staining platforms for reproducibility
Establish quality control measures for multi-center studies
Evidence indicates that high BFSP1 expression correlates with poor prognosis in liver cancer patients, suggesting its potential utility as a prognostic biomarker . The connection between BFSP1 and glycolytic metabolism further suggests possibilities for therapeutic targeting of this metabolic vulnerability in cancer.
Investigating the relationship between BFSP1 and cancer metabolism presents several methodological challenges:
Technical challenges in metabolic measurements:
Real-time metabolic flux analysis:
Metabolite quantification:
Sample collection timing (metabolism is highly dynamic)
Rapid quenching required to prevent post-collection changes
Appropriate extraction methods for different metabolite classes
Analytical platform selection (MS, NMR) based on targets
Genetic manipulation considerations:
Complex regulatory network mapping:
Untangling direct vs. indirect effects:
BFSP1-TMOD4 interaction effects on metabolism
METTL3-YTHDF1-BFSP1 axis regulation
Feedback loops between metabolic state and BFSP1 expression
Multi-omics data integration challenges
In vivo model limitations:
Tumor microenvironment effects on metabolism
Differences between cell line xenografts and patient tumors
Technical challenges in measuring metabolism in vivo
Controlling for confounding variables (tumor size, vascularization)
Translational research hurdles:
Heterogeneity in human tumor samples
Preservation of metabolic phenotypes in stored clinical specimens
Correlation between in vitro findings and clinical observations
Development of clinically applicable assays
Specific BFSP1-related challenges:
Distinguishing BFSP1's direct metabolic effects from its structural roles
Understanding tissue-specific functions (lens vs. liver)
Isolating the contribution of m6A modification to BFSP1's metabolic functions
Separating BFSP1-specific effects from general glycolytic regulation
Addressing these challenges requires multi-disciplinary approaches combining molecular biology, biochemistry, metabolomics, and computational modeling to fully characterize BFSP1's role in cancer metabolism.
Designing experiments to investigate BFSP1 as a therapeutic target requires a comprehensive approach:
Target validation experiments:
Genetic approaches:
CRISPR/Cas9-mediated knockout of BFSP1
Inducible shRNA systems for temporal control
Rescue experiments with wild-type vs. mutant BFSP1
Pharmacological approaches:
Small molecule screening against BFSP1 or BFSP1-TMOD4 interaction
Peptide inhibitors mimicking interaction domains
Assessment of existing drugs that may indirectly affect BFSP1 function
Therapeutic vulnerability assessment:
Synthetic lethality screening:
Combine BFSP1 inhibition with other therapeutic agents
Test sensitivity to metabolic inhibitors in BFSP1-high vs. BFSP1-low cells
Patient-derived models:
PDX models stratified by BFSP1 expression
Patient-derived organoids for ex vivo drug testing
Resistance mechanism identification:
Long-term BFSP1 inhibition studies
Identification of compensatory pathways
Mechanism-based combination strategies:
Target multiple points in the same pathway:
Synthetic lethality approaches:
Screen for genes that, when inhibited with BFSP1, cause cell death
Identify metabolic vulnerabilities specific to BFSP1-overexpressing cells
Pharmacodynamic biomarker development:
In vivo efficacy studies:
Orthotopic liver cancer models to maintain tissue context
Metastasis models to assess effects on cancer dissemination
Patient-derived xenografts to capture tumor heterogeneity
Monitoring both tumor growth and metabolic adaptation
Translational correlates:
Development of companion diagnostics for BFSP1 status
Identification of patient subgroups likely to respond to BFSP1-targeted therapy
Exploration of resistance mechanisms in non-responders
Biomarker analysis from clinical samples
This experimental framework provides a comprehensive approach to evaluating BFSP1 as a therapeutic target, with particular focus on its role in metabolic reprogramming and interaction with TMOD4 in liver cancer.
Several cutting-edge technologies hold promise for deepening our understanding of BFSP1 function:
Advanced RNA modification analysis:
DART-seq (Deamination Adjacent to RNA Modification Targets) for precise m6A mapping in BFSP1 mRNA
Nanopore direct RNA sequencing for real-time detection of modified bases
CRISPR-Cas13-based RNA tracking to visualize BFSP1 mRNA dynamics
Epitranscriptomic profiling to comprehensively map modifications beyond m6A
Protein interaction and structural biology:
Proximity labeling approaches (BioID, APEX) for comprehensive BFSP1 interactome mapping
Hydrogen-deuterium exchange mass spectrometry to map BFSP1-TMOD4 binding interfaces
Cryo-EM structural determination of BFSP1 and its complexes
Integrative structural biology combining multiple data types for complete structural models
Live-cell dynamics and functional imaging:
FRET/FLIM biosensors to monitor BFSP1-TMOD4 interactions in real-time
Optogenetic tools for spatiotemporal control of BFSP1 function
Correlative light and electron microscopy for ultrastructural localization
Metabolic imaging with fluorescent glucose analogs to directly visualize BFSP1's impact on glucose uptake
Single-cell technologies:
Single-cell RNA-seq with epitranscriptomic profiling capability
Single-cell proteomics to examine BFSP1 levels and modifications
Single-cell metabolomics to link BFSP1 expression to metabolic phenotypes
Spatial transcriptomics to map BFSP1 expression in tissue context
Computational and systems biology approaches:
Machine learning for prediction of BFSP1 regulatory networks
Multi-omics data integration across transcriptome, proteome, and metabolome
Genome-scale metabolic modeling to predict BFSP1's impact on flux distributions
Network analysis to position BFSP1 within cancer metabolic reprogramming
CRISPR-based functional genomics:
CRISPR screens to identify synthetic lethal partners with BFSP1
CRISPRi/CRISPRa for precise transcriptional modulation
Base editors or prime editors for introducing specific mutations in BFSP1
CRISPR-based epigenome editing to manipulate BFSP1 expression
These technologies would significantly enhance our ability to understand BFSP1's molecular functions, particularly its role in m6A-mediated regulation and metabolic reprogramming in cancer.
The most promising research directions for BFSP1 in cancer biology include:
Expanded cancer type investigation:
Beyond liver cancer, exploring BFSP1's role in other cancer types
Comparative analysis of BFSP1 function across tumor types
Pan-cancer bioinformatic analysis of BFSP1 expression and correlation with patient outcomes
Investigation of tissue-specific regulatory mechanisms controlling BFSP1 expression
Metabolism-focused investigations:
Detailed mapping of metabolic pathways affected by BFSP1 beyond glycolysis
Investigation of BFSP1's impact on mitochondrial function and oxidative phosphorylation
Exploration of metabolic plasticity and adaptation in response to BFSP1 modulation
Connection between BFSP1-mediated metabolic changes and therapy resistance
Regulatory network expansion:
Protein interaction network:
Therapeutic exploitation:
Development of direct BFSP1 inhibitors or BFSP1-TMOD4 interaction disruptors
Testing combination therapies targeting BFSP1 and glycolytic enzymes
Exploration of metabolic vulnerabilities created by BFSP1 overexpression
Development of BFSP1-based cancer biomarkers for patient stratification
Tumor microenvironment context:
Investigation of how BFSP1-induced metabolic changes affect the tumor microenvironment
Exploration of BFSP1's role in cancer cell-stromal cell metabolic crosstalk
Effects of hypoxia and nutrient limitation on BFSP1 function
BFSP1's potential contribution to immunosuppressive tumor metabolism
Clinical translation:
Development of standardized assays for BFSP1 detection in clinical samples
Prospective studies correlating BFSP1 expression with treatment response
Exploration of circulating BFSP1 as a potential liquid biopsy marker
Clinical trials incorporating BFSP1 status in patient stratification
These research directions would collectively advance our understanding of BFSP1's role in cancer biology and potentially lead to new diagnostic and therapeutic strategies.