cep290 Antibody

What is CEP290 and why is it significant in research?

CEP290 (centrosomal protein of 290 kDa) is a crucial scaffold protein that plays essential roles in centrosome assembly, cell division, and microtubule organization. Its significance in research stems from its critical function in the localization of ciliary and phototransduction proteins in retinal photoreceptor cells, making it vital for vision . CEP290 is particularly important in studying ciliopathies, as mutations in this gene can lead to several severe genetic disorders including Joubert syndrome type 5, Senior-Løken syndrome type 6, Leber congenital amaurosis type 10, and Meckel syndrome type 4 . This protein has been established as a critical component of Y-link junctions in cilia, as demonstrated through studies in Chlamydomonas model systems .

What types of CEP290 antibodies are available for research applications?

Two primary types of CEP290 antibodies are documented in the literature for research applications:

• Mouse monoclonal antibodies: The CEP290 Antibody (B-7) from Santa Cruz Biotechnology (sc-390462) is a mouse monoclonal IgG1 kappa light chain antibody that effectively detects CEP290 protein of human origin .

• Rabbit polyclonal antibodies: The Proteintech antibody (22490-1-AP) is a rabbit polyclonal IgG that targets CEP290 in various applications with confirmed reactivity in human samples and cited reactivity in mouse samples .

Both antibody types are available in multiple formats, including non-conjugated forms and various conjugated versions (agarose, HRP, PE, FITC, and multiple Alexa Fluor conjugates), providing researchers with flexibility based on specific experimental needs .

What are the validated applications for CEP290 antibodies?

CEP290 antibodies have been validated for multiple research applications, with specific dilution recommendations for optimal results:

Both antibody types have demonstrated reactivity with human samples, with the polyclonal antibody also showing cited reactivity with mouse samples . It is recommended that researchers titrate these antibodies in each testing system to obtain optimal results, as the effectiveness can be sample-dependent .

How should CEP290 antibodies be stored and handled to maintain their effectiveness?

For optimal preservation of antibody activity, CEP290 antibodies should be stored according to manufacturer recommendations. The polyclonal antibody from Proteintech should be stored at -20°C in PBS with 0.02% sodium azide and 50% glycerol at pH 7.3 . These storage conditions ensure stability for one year after shipment. Importantly, aliquoting is unnecessary for -20°C storage of this particular antibody preparation, which simplifies laboratory handling protocols . The 20 μl size preparations contain 0.1% BSA as a stabilizer. Proper storage and handling are essential to maintain antibody specificity and sensitivity, particularly for applications requiring precise detection of the 290 kDa protein.

How can I validate the specificity of a CEP290 antibody for my particular experimental system?

Validating CEP290 antibody specificity requires a multi-faceted approach, particularly given its large molecular weight (290 kDa) and the potential for cross-reactivity:

• Knockdown/Knockout Validation: Use CEP290 knockdown or knockout samples as negative controls. Published studies have utilized this approach, with at least 3 publications documenting KD/KO validation techniques for CEP290 antibodies .

• Multiple Antibody Approach: Compare results using antibodies targeting different epitopes of CEP290. Research has shown that antibodies recognizing the C-terminus versus N-terminus of CEP290 show different localization patterns, with C-terminal antibodies localizing closer to microtubules (centered at 100 nm from cilium center) and N-terminal antibodies closer to the membrane (centered at 130 nm) .

• Western Blot Analysis: Confirm a single band at the expected molecular weight (290 kDa) in appropriate positive control cells such as HeLa cells, which have been experimentally validated as positive controls for both Western blot and immunoprecipitation applications .

• Immunofluorescence Pattern Assessment: Compare your staining pattern with published localization data showing CEP290 between the doublet microtubules and ciliary membrane in connecting cilia, with a symmetrical pattern near Y-links in both human and murine photoreceptors .

What methodological adaptations are necessary when using CEP290 antibodies for immuno-electron microscopy?

For successful immuno-electron microscopy with CEP290 antibodies, several critical methodological considerations must be addressed:

• Fixation and Processing: Adapt protocols specifically optimized for ciliary antigens. Recent research successfully used a protocol optimized for mouse rod connecting cilium (CC) antigens when studying CEP290 localization .

• Antibody Selection: Consider using both C-terminal and N-terminal recognizing antibodies to obtain complementary localization data. Research has shown different radial distributions for these antibodies relative to the cilium center (C-terminal: centered at 100 nm; N-terminal: centered at 130 nm) .

• Visualization Enhancement: Employ nanogold secondary antibodies with silver enhancement (referred to as silver enhanced gold cluster, SEGC) to improve visibility of the protein in electron micrographs .

• Quantitative Analysis: For precise localization analysis, calculate radial distributions of each SEGC from the centers of each ciliary structure. Only use near-circular sections for accurate measurements and exclude elliptical sections that might distort distance calculations .

• Control Comparisons: Include parallel staining of other ciliary proteins (such as RPGR) for comparative localization assessment. This approach helped researchers determine that CEP290 and RPGR have distinct but overlapping distributions in the connecting cilium .

How do CEP290 antibodies perform in detecting different protein isoforms or post-translationally modified forms?

The detection of specific CEP290 isoforms and post-translationally modified forms requires careful antibody selection and experimental design:

• Isoform Detection: While the primary literature does not specifically address CEP290 isoform detection, comparative studies with interacting proteins like RPGR demonstrate the importance of isoform-specific antibodies. RPGR exists in a constitutive form (containing 19 exons) and a retina-enriched isoform (containing exon 15 plus a portion of intron 15), and specific antibodies have been developed to distinguish between these variants .

• Post-translational Modifications: When studying proteins that interact with CEP290, such as RPGR, researchers have successfully used modification-specific antibodies like the polyglutamate-specific antibody GT335 to detect glutamylated forms of the protein . Similar approaches could be applied to CEP290 studies when investigating potential post-translational modifications.

• Mutation-Affected Detection: In CEP290 mutant retinas, protein detection may be affected, requiring careful antibody epitope selection. For instance, studies revealed that RPGR (a CEP290 interactor) is mislocalized in CEP290 mutant connecting cilia, being largely absent from the proximal region near the ciliary rootlet or confined to a shorter proximal region .

What are the key considerations when designing co-localization studies involving CEP290 and other ciliary proteins?

Co-localization studies involving CEP290 and other ciliary proteins require precise methodological approaches:

• Selection of Compatible Antibodies: Choose primary antibodies raised in different host species to prevent cross-reactivity. When studying CEP290 alongside RPGR, researchers successfully used different species-derived antibodies for simultaneous labeling .

• High-Resolution Imaging Techniques: Employ super-resolution microscopy methods such as Structured Illumination Microscopy (SIM) or immunogold TEM for accurate spatial resolution. Recent research combined these techniques to precisely determine the relative positions of CEP290 and RPGR within the connecting cilium .

• Quantitative Distance Measurement: Implement rigorous quantitative analysis of radial distributions. Studies have shown that while doublet microtubules have a tight radial distribution centered at 80 nm from the cilium center, CEP290 C-terminal epitopes distribute more broadly around 100 nm, and N-terminal epitopes around 130 nm .

• Functional Relationship Assessment: Design experiments to assess potential functional relationships between co-localized proteins. Research demonstrated that uniform RPGR localization throughout the connecting cilium requires the presence of full-length CEP290, providing insights into their functional relationship .

How should I design experiments to study the role of CEP290 in ciliopathies using antibody-based approaches?

When designing experiments to investigate CEP290's role in ciliopathies using antibody-based approaches, consider these systematic steps:

• Model Selection: Choose appropriate model systems based on your specific ciliopathy focus. For Leber Congenital Amaurosis, both mouse models and human samples have been successfully employed . Different mutations in CEP290 can lead to distinct ciliopathies (Joubert syndrome type 5, Senior-Løken syndrome type 6, Leber congenital amaurosis type 10, and Meckel syndrome type 4), so select models that recapitulate the specific disease phenotype .

• Multi-technique Approach: Implement a combination of techniques for comprehensive analysis:

  • Immunofluorescence for protein localization and co-localization studies

  • Immunogold electron microscopy for ultrastructural localization

  • Immunoblotting for protein expression level analysis

  • Immunoprecipitation for protein interaction studies

• Comparative Analysis: Include both wild-type and mutant samples to identify mutation-specific effects. Recent research demonstrated that RPGR localization is disrupted in CEP290 mutant connecting cilia, providing insights into disease mechanisms .

• Functional Correlation: Correlate structural findings with functional assays. For example, after determining CEP290's localization pattern in photoreceptors, researchers investigated how mutations affect interacting proteins and ultimately impact vision .

What controls are essential when using CEP290 antibodies for quantitative immunofluorescence or western blot analysis?

Implementing appropriate controls is critical for reliable quantitative analysis with CEP290 antibodies:

For Western Blot Analysis:

• Positive Control: Include validated positive control samples such as HeLa cell lysates, which have been confirmed to express detectable levels of CEP290 .

• Negative Control: Use either CEP290 knockout/knockdown samples or tissues known not to express CEP290.

• Loading Control: Include antibodies against housekeeping proteins (such as β-actin, GAPDH) to normalize protein loading.

• Molecular Weight Marker: Essential for confirming the expected 290 kDa band size.

• Antibody Concentration Gradient: Perform titration experiments (e.g., 1:500, 1:750, 1:1000 dilutions) to determine optimal antibody concentration for linear signal response .

For Quantitative Immunofluorescence:

• Secondary Antibody-Only Control: To assess background fluorescence.

• Isotype Control: Using non-specific IgG of the same isotype as the primary antibody.

• Peptide Competition Control: Pre-incubating the antibody with the immunizing peptide to verify specificity.

• Positive Tissue Control: Include samples with known CEP290 expression patterns (e.g., MCF-7 cells, HeLa cells) .

• Image Acquisition Standards: Maintain consistent microscope settings across all samples.

• Signal Quantification Protocol: Establish rigorous protocols for fluorescence intensity measurement and background subtraction.

How can I optimize CEP290 antibody performance for challenging tissue samples such as retinal sections?

Optimizing CEP290 antibody performance for challenging retinal tissues requires specialized approaches:

• Antigen Retrieval Optimization: For retinal tissues, test multiple antigen retrieval methods. For IHC applications with the polyclonal antibody, suggested protocols include:

  • Primary recommendation: TE buffer pH 9.0

  • Alternative method: Citrate buffer pH 6.0

• Fixation Protocol Refinement: Adapt fixation protocols specifically for retinal tissues:

  • For immunogold EM studies of retinal samples, researchers successfully used protocols specifically optimized for mouse rod connecting cilium antigens

  • Consider short fixation times to prevent overfixation and epitope masking

• Section Thickness Considerations: For retinal architecture preservation:

  • For immunofluorescence: Use 8-12 μm sections to maintain structural integrity

  • For EM studies: Use ultrathin sections (70-100 nm) for optimal resolution

• Background Reduction Techniques:

  • Include longer blocking steps (2-3 hours at room temperature)

  • Use specialized blocking solutions containing both serum and BSA

  • Consider adding 0.1-0.3% Triton X-100 for improved antibody penetration in IF applications

• Signal Enhancement Methods:

  • For fluorescence: Use tyramide signal amplification systems

  • For EM: Employ silver enhancement of nanogold secondary antibodies as successfully demonstrated in recent CEP290 localization studies

What methodological approaches can address the challenges of detecting CEP290 in ciliary structures due to its large molecular weight?

The 290 kDa size of CEP290 presents specific technical challenges for detection that can be addressed through tailored methodological approaches:

• Protein Extraction Optimization:

  • Use specialized lysis buffers containing strong detergents (such as 1% SDS) for complete solubilization

  • Incorporate lengthy extraction times (30+ minutes on ice with regular vortexing)

  • Consider sonication to shear DNA and improve high molecular weight protein extraction

• Western Blot Protocol Adaptations:

  • Utilize low percentage gels (5-6% polyacrylamide) for better resolution of high molecular weight proteins

  • Extend transfer times (overnight at low voltage) using specialized buffers for high molecular weight proteins

  • Implement semi-dry transfer systems with programmed increasing current protocols

• Immunofluorescence Enhancement:

  • Extend permeabilization times to ensure antibody access to ciliary structures

  • Consider mild proteolytic treatment to improve epitope accessibility

  • Use appropriate confocal microscopy settings optimized for ciliary structures

• Specific Antibody Selection:

  • Choose antibodies validated for detection of full-length CEP290 rather than fragments

  • Consider using antibodies targeting distinct epitopes (N-terminal and C-terminal) to provide complementary localization data, as demonstrated in recent research showing these antibodies localize to different radial positions within the connecting cilium

How can I troubleshoot non-specific or weak signals when using CEP290 antibodies in western blot applications?

When encountering non-specific or weak signals with CEP290 antibodies in western blot applications, implement this systematic troubleshooting approach:

For Non-specific Signals:

• Blocking Optimization: Extend blocking time (2+ hours) and test alternative blocking agents (5% milk vs. 5% BSA).

• Antibody Dilution Adjustment: For the polyclonal antibody, test more dilute concentrations within the recommended 1:500-1:1000 range .

• Washing Protocol Enhancement: Increase washing time and volume, using fresh TBST or PBST buffers.

• Sample Preparation Refinement:

  • Ensure complete denaturation of samples (95-100°C for 10 minutes)

  • Add protease inhibitors to prevent degradation

  • Consider fresh sample preparation as CEP290 may be susceptible to degradation during storage

For Weak Signals:

• Protein Loading Increase: For the high molecular weight CEP290 (290 kDa), increase protein loading to 50-75 μg per lane.

• Detection System Enhancement: Switch to more sensitive detection methods such as chemiluminescent substrates with longer signal duration.

• Transfer Protocol Optimization: For this large protein, extend transfer time and adjust buffer composition to enhance transfer efficiency.

• Antibody Concentration Adjustment: Test higher antibody concentrations at the upper end of the recommended range.

• Alternative Antibody Format: Consider using HRP-conjugated primary antibodies (such as CEP290 Antibody (B-7) HRP) to eliminate secondary antibody signal amplification variability .

What are common pitfalls in interpreting immunofluorescence localization data for CEP290, and how can they be avoided?

Interpreting CEP290 immunofluorescence localization data requires awareness of several potential pitfalls:

• Misinterpretation of Ciliary Versus Centrosomal Staining:

  • Pitfall: Confusing CEP290 staining at the centrosome with its ciliary localization.

  • Solution: Use co-staining with established markers (e.g., γ-tubulin for centrosomes, acetylated tubulin for cilia) to distinguish these structures. Recent research has clearly demonstrated CEP290 localization between doublet microtubules and ciliary membrane in connecting cilia .

• Projection Artifacts in Microscopy:

  • Pitfall: Maximum intensity projections can create false co-localization impressions.

  • Solution: Analyze individual Z-sections and use orthogonal views to confirm three-dimensional localization patterns. Studies have shown CEP290 has specific radial distributions that require careful three-dimensional analysis .

• Antibody Cross-Reactivity:

  • Pitfall: Misattributing signals from cross-reacting proteins to CEP290.

  • Solution: Validate antibody specificity using knockout controls and peptide competition assays. At least three publications have documented knockout validation approaches for CEP290 antibodies .

• Resolution Limitations:

  • Pitfall: Standard confocal microscopy may not resolve the precise localization within ciliary structures.

  • Solution: Employ super-resolution techniques such as structured illumination microscopy (SIM) or STORM/PALM for accurate localization, as successfully implemented in recent CEP290 research .

• Sample Preparation Artifacts:

  • Pitfall: Fixation can alter protein localization patterns.

  • Solution: Compare multiple fixation methods and correlate findings with live-cell imaging where possible.

How should I analyze data from co-immunoprecipitation experiments involving CEP290 and potential interaction partners?

Analysis of co-immunoprecipitation (co-IP) data involving CEP290 requires rigorous controls and quantitative approaches:

• Essential Controls for Valid Interpretation:

  • Input Control: Analyze 5-10% of the pre-IP lysate to confirm target protein presence.

  • Negative IP Control: Use non-immune IgG matching the host species of the IP antibody.

  • Reverse Co-IP Validation: Confirm interactions by performing the co-IP in reverse (immunoprecipitate the partner and probe for CEP290).

  • Specificity Control: Include a known non-interacting protein to verify specific precipitation.

• Quantitative Analysis Approach:

  • Calculate enrichment ratios (IP signal/input signal) for both CEP290 and interacting partners.

  • Compare these ratios to establish the strength of interactions.

  • Perform replicate experiments (n≥3) and apply appropriate statistical analyses.

• Protocol Optimization Considerations:

  • For CEP290 co-IP, use 0.5-4.0 μg of antibody for 1.0-3.0 mg of total protein lysate, as recommended for the polyclonal antibody .

  • Consider native versus crosslinked conditions based on interaction strength.

  • Test different detergent concentrations to balance solubilization and interaction preservation.

• Validation of Novel Interactions:

  • Confirm functional relevance through additional approaches (proximity ligation assay, FRET, etc.).

  • Correlate interaction data with localization studies, as demonstrated in research showing both CEP290 and RPGR localize to similar regions in connecting cilia .

  • For publications, include full blots with molecular weight markers to demonstrate specificity.

How can I integrate CEP290 antibody-based findings with genetic data to advance understanding of ciliopathies?

Integrating antibody-based findings with genetic data requires a multidisciplinary approach that connects protein function with disease mechanisms:

• Genotype-Phenotype Correlation Analysis:

  • Compare CEP290 protein localization and expression levels across samples with different mutation types (missense, nonsense, frameshift).

  • Correlate antibody-detected protein alterations with specific clinical manifestations across the spectrum of CEP290-related ciliopathies.

  • Research has shown that the most common genetic cause of Leber Congenital Amaurosis is mutation of the CEP290 gene, making this correlation particularly relevant .

• Functional Domain Mapping:

  • Use antibodies targeting different epitopes (N-terminal versus C-terminal) to determine which protein domains remain intact in patient samples with various mutations.

  • Recent research has shown different localization patterns for N-terminal (closer to membrane) versus C-terminal (closer to microtubules) epitopes, providing insights into the protein's functional organization .

• Interaction Network Analysis:

  • Combine co-IP data with genetic interaction screens to build comprehensive interaction maps.

  • Assess how disease-causing mutations affect these interactions.

  • Studies have demonstrated that CEP290 mutations affect the localization of interacting proteins like RPGR, contributing to disease mechanisms .

• Model System Validation:

  • Test antibody-detected molecular phenotypes in genetically engineered model systems (CRISPR-modified cell lines, animal models).

  • Validate therapeutic approaches targeting specific protein domains using domain-specific antibodies.

  • Research utilizing CEP290 mutant models has revealed that uniform RPGR localization throughout the connecting cilium requires full-length CEP290, demonstrating the value of this integrated approach .

How are CEP290 antibodies being used to validate gene therapy approaches for CEP290-related retinal diseases?

CEP290 antibodies play a critical role in validating gene therapy approaches for CEP290-related retinal diseases through several methodological applications:

• Therapeutic Protein Expression Verification:

  • CEP290 antibodies enable researchers to confirm expression of the therapeutic transgene following delivery via AAV or lentiviral vectors.

  • Quantitative western blot and immunofluorescence analyses can determine if therapeutic expression reaches physiological levels in target tissues.

• Cellular Localization Assessment:

  • Immunofluorescence using CEP290 antibodies helps verify that therapeutically expressed protein correctly localizes to ciliary structures.

  • Super-resolution microscopy with these antibodies can confirm restoration of the normal radial distribution pattern between doublet microtubules and ciliary membrane that has been characterized in recent research .

• Functional Recovery Correlation:

  • CEP290 antibodies help correlate protein restoration with recovery of ciliary structural integrity.

  • Immunogold EM with these antibodies enables assessment of Y-link restoration in treated tissues.

• Downstream Protein Restoration Analysis:

  • Since CEP290 mutations affect localization of other proteins like RPGR, antibodies against both proteins can verify if gene therapy restores normal protein interaction networks.

  • Research has demonstrated that RPGR is mislocalized in CEP290 mutant connecting cilia, providing a measurable endpoint for therapeutic efficacy .

What methodological approaches can distinguish between different patient-specific CEP290 mutations using antibody-based techniques?

Distinguishing between different patient-specific CEP290 mutations using antibody-based techniques requires tailored methodological approaches:

• Epitope-Specific Antibody Selection Strategy:

  • Choose antibodies targeting regions upstream and downstream of common mutation sites.

  • For truncating mutations, use C-terminal antibodies to verify protein truncation while N-terminal antibodies confirm expression of the partial protein.

  • Research has shown that antibodies recognizing different epitopes (N-terminal vs. C-terminal) show different localization patterns, which can be leveraged for mutation analysis .

• Western Blot Size Differentiation Analysis:

  • Detect truncated proteins or altered splice variants resulting from different mutations.

  • Implement gradient gels (4-12%) for optimal resolution of both full-length and truncated forms.

  • Use size standards for precise molecular weight determination.

• Immunofluorescence Localization Pattern Assessment:

  • Different mutations may result in distinct mislocalization patterns that can be detected via high-resolution immunofluorescence.

  • Apply quantitative image analysis to measure subtle differences in localization patterns between mutation types.

  • Compare to established patterns showing CEP290 between doublet microtubules and ciliary membrane .

• Functional Antibody Arrays for Mutation Impact:

  • Develop antibody arrays targeting multiple epitopes across the CEP290 protein.

  • Apply patient samples to these arrays to create "epitope fingerprints" characteristic of specific mutations.

  • Correlate these patterns with clinical phenotypes to advance personalized treatment approaches.

How can advanced microscopy techniques be combined with CEP290 antibodies to reveal new insights into ciliary biology?

Combining advanced microscopy with CEP290 antibodies opens new frontiers in understanding ciliary biology:

• Super-Resolution Microscopy Applications:

  • Structured Illumination Microscopy (SIM) enables visualization of CEP290's precise arrangement within ciliary Y-links.

  • STORM/PALM microscopy can resolve individual CEP290 molecules at nanometer resolution, revealing potential oligomerization patterns.

  • Recent research successfully employed SIM to reveal that the retina-specific splice variant of RPGR (an interactor of CEP290) is mislocalized in CEP290 mutant connecting cilia .

• Correlative Light and Electron Microscopy (CLEM):

  • This powerful approach correlates fluorescence localization of CEP290 with ultrastructural features.

  • Enables direct correlation between protein localization and ciliary structural elements at nanometer resolution.

  • Recent research combined immunofluorescence microscopy with immunogold electron microscopy to precisely localize CEP290 between the axoneme and membrane throughout the connecting cilium .

• Live-Cell Super-Resolution Approaches:

  • Combining CRISPR-mediated tagging with antibody fragment imaging enables dynamic analysis of CEP290.

  • Can reveal transport mechanisms and turnover rates in living ciliated cells.

• Expansion Microscopy Potential:

  • Physical expansion of specimens combined with conventional microscopy achieves super-resolution-like results.

  • Has been successfully applied to ciliary proteins and could reveal new details about CEP290 organization.

  • Recent publications cited in the search results reference findings from iterative expansion protocols applied to CEP290 localization .

What are the methodological considerations for using CEP290 antibodies in high-throughput screening applications?

Adapting CEP290 antibody-based assays for high-throughput screening requires specific methodological considerations:

• Assay Miniaturization Strategy:

  • Optimize antibody concentrations for microplate formats (96, 384, or 1536-well).

  • Determine minimum cell numbers required for reliable detection.

  • Validate signal-to-background ratios in miniaturized format using positive controls (HeLa cells) and negative controls (knockdown samples).

• Automated Immunofluorescence Protocol Development:

  • Standardize fixation, permeabilization, and staining protocols for robotic liquid handlers.

  • Implement dual staining with ciliary markers for automated image analysis.

  • Establish robust washing procedures to minimize background while maintaining throughput.

• Image Acquisition and Analysis Pipelines:

  • Develop automated microscopy protocols focusing on ciliary regions.

  • Implement machine learning algorithms to recognize normal versus abnormal CEP290 localization patterns.

  • Create analysis pipelines that quantify multiple parameters (intensity, localization, co-localization with partners).

• Assay Validation Requirements:

  • Determine Z'-factor to assess assay quality (aim for Z'>0.5).

  • Establish dose-response curves with known modulators.

  • Include controls on each plate to monitor plate-to-plate variability.

  • Validate hits with secondary assays using alternative antibodies or detection methods.