CLCN7 Antibody

What is CLCN7 and why is it important for researchers to study?

CLCN7 (Chloride Voltage-Gated Channel 7) is a lysosomal membrane protein that functions as a Cl⁻/H⁺ antiporter, critical for maintaining lysosomal pH and function. It has a canonical amino acid length of 805 residues and a protein mass of approximately 88.7 kilodaltons in humans, with two identified isoforms . CLCN7 is widely expressed across tissue types and primarily localized in lysosomes .

This protein is of significant research interest because mutations in CLCN7 are associated with several disorders, including:

• Autosomal dominant osteopetrosis type 2 (OPTA2/Albers-Schönberg disease)

• Autosomal recessive osteopetrosis type 4 (OPTB4/infantile malignant osteopetrosis type 2)

• Hypopigmentation, organomegaly, and delay in axon myelination and development (HOD syndrome)

Recent research has demonstrated that CLCN7 constitutes the major route for chloride ion flux across the lysosomal membrane, and knockdown of CLCN7 expression significantly reduces the ability of lysosomes to acidify in vivo . This critical role in lysosomal pH regulation makes CLCN7 antibodies valuable tools for investigating lysosomal disorders, bone diseases, and cell biology.

What applications are validated for CLCN7 antibodies?

CLCN7 antibodies have been validated for multiple experimental applications, with varying degrees of optimization across different commercial antibodies. Based on the available data, the primary applications include:

When designing experiments, researchers should consider that CLCN7 antibodies have been demonstrated to work effectively in human, mouse, and rat samples . For optimal results, validation in your specific experimental system is recommended, as observed molecular weights may vary (typically between 70-110 kDa) depending on post-translational modifications and detection methods .

How should CLCN7 antibodies be stored and handled for optimal performance?

Proper storage and handling of CLCN7 antibodies is critical for maintaining their performance and longevity. Based on manufacturer recommendations:

Storage Conditions:

• Long-term storage: -20°C is universally recommended

• Short-term storage (up to 1 week): 4°C may be acceptable for reconstituted antibodies

• Some antibodies are supplied in glycerol solutions (typically 50%) to prevent freeze-thaw damage

Handling Recommendations:

• Minimize freeze-thaw cycles by preparing small aliquots before freezing

• Centrifuge antibody preparations before use (10,000 x g for 5 min)

• For lyophilized antibodies, reconstitution with double-distilled water (DDW) is typically recommended

• Some preparations contain preservatives like sodium azide (0.02%) which should be considered when designing certain experiments

Stability Information:

• Most CLCN7 antibodies maintain stability for approximately 12 months from shipment when stored properly

• After reconstitution, most products remain stable at 4°C for up to one week

These handling practices will help ensure experimental reproducibility and maximize antibody lifespan.

What are the critical factors for optimizing Western blot protocols with CLCN7 antibodies?

Optimizing Western blot protocols for CLCN7 detection requires attention to several critical factors:

Sample Preparation:

• CLCN7 is a lysosomal membrane protein, requiring effective membrane protein extraction protocols

• The observed molecular weight varies between suppliers (70-110 kDa) , with the calculated molecular weight being 89 kDa

• Complete protein denaturation is essential; some researchers report using additional reducing agents

Antibody Selection and Dilution:

• For Western blot applications, dilutions typically range from 1:500 to 1:4000

• Different epitope targets are available, including C-terminal specific antibodies

• The Proteintech antibody (29230-1-AP) has been validated in mouse brain, kidney, and small intestine tissues

Protocol Optimization:

• The RayBiotech CLCN7 antibody protocol specifies using 35 μg/lane of cell lysate (CEM cell line) for effective detection

• When comparing different tissues, expression levels may vary significantly

• Some manufacturers provide specialized protocols optimized for their specific antibody preparations

Controls and Validation:

• Positive controls in tissues known to express CLCN7 (brain, kidney, small intestine) are recommended

• Recombinant CLCN7 protein fragments can serve as positive controls for antibody validation

• To confirm specificity, some researchers have used siRNA knockdown of CLCN7 expression

Careful optimization of these parameters will help ensure specific detection of CLCN7 in Western blot applications.

How can researchers effectively use CLCN7 antibodies to study lysosomal function and pH regulation?

CLCN7 antibodies have proven valuable for investigating lysosomal function and pH regulation, as CLCN7 plays a critical role in lysosomal acidification. Methodological approaches include:

Lysosomal pH Assessment:

• Combined immunofluorescence with pH-sensitive dyes: CLCN7 antibodies can be used to label lysosomes while simultaneously measuring pH with ratiometric dyes

• Studies have demonstrated that CLCN7 dysfunction (both loss- and gain-of-function) impacts lysosomal pH

• Research by Nicoli et al. (2019) showed that gain-of-function CLCN7 variants led to increased lysosomal acidity (pH reduction of approximately 0.2 units)

Colocalization Studies:

• CLCN7 antibodies can be used in conjunction with other lysosomal markers

• Confocal immunofluorescent analysis has been performed with CLCN7 antibodies (such as RayBiotech catalog #102-11287) in cell lines like WiDr, followed by fluorescent secondary antibody detection

• DAPI is commonly used as a nuclear counterstain in these applications

Functional Studies:

• Recent research demonstrated that treatment with chloroquine (a lysosomotropic alkalinizing agent) could reverse the vacuolar phenotype in cells with gain-of-function CLCN7 variants

• Researchers have used CLCN7 antibodies to monitor protein levels following siRNA knockdown to correlate with changes in lysosomal acidification

• Studies by Bose et al. (2023) used CLCN7 antibodies to investigate the effects of CLCN7 variants on autophagy markers LC3-II and p62

When designing experiments to study lysosomal function, it's important to note that ClC-7 functions as a dimer and requires its β-subunit OSTM1 for proper activity . This interaction should be considered when interpreting results of CLCN7 antibody studies.

What are the key considerations when using CLCN7 antibodies for immunohistochemistry or immunofluorescence?

When using CLCN7 antibodies for immunohistochemistry (IHC) or immunofluorescence (IF), several methodological considerations should be addressed:

Tissue Preparation:

• For IHC, formalin-fixed paraffin-embedded (FFPE) tissues have been successfully used with CLCN7 antibodies

• The RayBiotech CLCN7 antibody has been validated in human kidney tissue with proper fixation and embedding protocols

• Antigen retrieval methods may be necessary due to formalin fixation masking epitopes

Antibody Selection:

• For IHC applications, polyclonal antibodies like the OriGene CLC7 Rabbit Polyclonal Antibody are specifically designed for IHC use

• Some antibodies are suitable for both IHC and IF applications, while others may be optimized for only one technique

• The Atlas Antibodies CLCN7 antibody has been validated for both IF (0.25-2 μg/mL) and IHC (1:200-1:500)

Detection Systems:

• For IHC: The RayBiotech protocol specifies using peroxidase conjugation of secondary antibodies followed by DAB staining

• For IF: Alexa Fluor 488-conjugated secondary antibodies have been successfully used with CLCN7 primary antibodies

• Nuclear counterstaining with DAPI can provide context for cellular localization

Control Samples:

• Positive control tissues with known CLCN7 expression should be included

• Antibody validation through the Human Protein Atlas project provides extensive tissue array testing across 44 normal human tissues

• Negative controls (omitting primary antibody) are essential to assess background staining

Interpretation Considerations:

• CLCN7 is predominantly localized to lysosomes, so expect a punctate cytoplasmic staining pattern

• In cells with gain-of-function CLCN7 variants, enlarged cytoplasmic vacuoles may be observed

• Clinical relevance of staining patterns should be interpreted cautiously, as noted in the RayBiotech documentation

For optimal results, researchers should follow manufacturer-recommended dilutions and protocols, which have been validated for specific applications.

How can CLCN7 antibodies be used to investigate disease-associated CLCN7 variants?

CLCN7 antibodies serve as powerful tools for investigating disease-associated variants, particularly in distinguishing between loss-of-function and gain-of-function mutations. Methodological approaches include:

Variant Detection and Expression Analysis:

• Western blot analysis can detect altered expression levels or molecular weight shifts in mutant CLCN7 proteins

• Immunofluorescence microscopy reveals subcellular localization changes in mutant proteins

• In patient-derived fibroblasts with the Y715C gain-of-function variant, CLCN7 antibodies helped identify pathologically enlarged cytoplasmic vacuoles

Functional Characterization:

• CLCN7 antibodies have been used to monitor protein expression in cells transfected with mutant CLCN7 constructs

• Nicoli et al. (2019) demonstrated that overexpression of Y715C mutant CLCN7 in control fibroblasts partially replicated the vacuolar phenotype seen in patient cells

• Combining antibody-based detection with functional assays like lysosomal pH measurement provides comprehensive assessment of variant effects

Disease Model Studies:

• CLCN7 antibodies have enabled characterization of novel disease phenotypes beyond classical osteopetrosis

• Recent research identified a multisystem disorder associated with the Y715C variant, characterized by albinism, hypogammaglobulinemia, and organomegaly without osteopetrosis

• Mouse models engineered with corresponding human variants have been studied using CLCN7 antibodies to confirm pathogenicity

Therapeutic Development:

• CLCN7 antibodies have helped evaluate potential treatments for CLCN7-related disorders

• Studies showed chloroquine treatment could reverse the vacuolar phenotype and normalize lysosomal pH in cells with gain-of-function CLCN7 variants

• This approach highlights how antibody-based detection can support pharmacological screening and mechanism studies

When studying disease-associated variants, researchers should consider using antibodies targeting different epitopes, as mutations may affect antibody binding in region-specific antibodies.

What challenges exist in detecting CLCN7 in different experimental systems and how can they be overcome?

Detecting CLCN7 across different experimental systems presents several technical challenges that researchers should address:

Variable Molecular Weight Detection:

• The observed molecular weight of CLCN7 varies between reports (70-110 kDa) despite a calculated weight of 89 kDa

• This variability may result from post-translational modifications, splice variants, or technical factors

• Solution: Use positive controls with known CLCN7 expression and size markers appropriate for your experimental system

Tissue-Specific Expression Levels:

• CLCN7 expression varies across tissues, with notable presence in brain, kidney, and small intestine

• Low expression in certain tissues may require sensitivity optimization

• Solution: Adjust protein loading (up to 35 μg/lane has been validated) and consider using enhanced chemiluminescence detection systems for Western blots

Membrane Protein Extraction Efficiency:

• As a lysosomal membrane protein, CLCN7 may be difficult to extract efficiently

• Standard protein extraction methods may yield inconsistent results

• Solution: Use dedicated membrane protein extraction buffers containing appropriate detergents; some researchers report success with RIPA buffer containing protease inhibitors

Antibody Cross-Reactivity:

• Some CLCN7 antibodies may cross-react with other CLC family members

• This is particularly relevant when studying tissues expressing multiple CLC proteins

• Solution: Validate antibody specificity through siRNA knockdown experiments or use knockout/negative controls

Fixation and Antigen Retrieval for IHC/IF:

• Formalin fixation can mask CLCN7 epitopes, particularly in FFPE tissues

• Different epitopes may require different antigen retrieval methods

• Solution: Optimize antigen retrieval protocols (heat-induced or enzymatic) and test multiple fixation methods if possible

By addressing these challenges through careful optimization and appropriate controls, researchers can improve the reliability and reproducibility of CLCN7 detection across experimental systems.

How do different types of CLCN7 antibodies compare in detecting specific functional domains and isoforms?

Various CLCN7 antibodies target different epitopes, affecting their ability to detect specific functional domains and isoforms. Understanding these differences is crucial for experimental design:

Epitope Targeting and Functional Domains:

CLCN7 antibodies can be categorized based on their target regions:

Isoform Detection:

• Human CLCN7 has two reported isoforms , and antibody selection should consider which isoforms are relevant to your research

• Antibodies targeting conserved regions may detect multiple isoforms

• Western blot analysis should be interpreted with awareness that different isoforms may appear as multiple bands

Mutation Detection Considerations:

• For studying the Y715C gain-of-function variant, C-terminal antibodies (such as RayBiotech #102-11287) targeting this region are particularly relevant

• Some mutations may disrupt antibody binding if they occur within the epitope region

• Using antibodies targeting different domains can help verify results and provide complementary information

Functional Correlations:

• The C-terminal domain contains regulatory regions important for CLCN7 function

• Antibodies targeting amino acids 626-805 (like those from RayBiotech and Abbexa) cover a region important for protein-protein interactions

• The sequence "TARE VMST PVTC LRRR EKVG VIVD VLSD TASN HNGF PVVE HADD TQPA RLQG LILR SQLI VLLK HKVF VERS" is included in several immunogens and contains functionally significant regions

When selecting CLCN7 antibodies, researchers should consider which domains and isoforms are most relevant to their specific research questions and choose antibodies with appropriate epitope targeting.

What are the most effective strategies for validating CLCN7 antibody specificity in research applications?

Validating CLCN7 antibody specificity is essential for generating reliable research data. Several complementary approaches can be employed:

Genetic Approaches:

• siRNA/shRNA knockdown: Reducing CLCN7 expression via RNA interference should correspondingly decrease antibody signal

• CRISPR/Cas9 knockout: Complete elimination of CLCN7 expression provides a definitive negative control

• Overexpression: Transfection with CLCN7 expression constructs should increase antibody signal proportionally

Biochemical Validation:

• Peptide competition: Pre-incubating the antibody with the immunizing peptide should block specific binding

• Recombinant protein array testing: Some CLCN7 antibodies have been validated against arrays of 364 human recombinant protein fragments to assess cross-reactivity

• Western blot molecular weight verification: Confirming detection at the expected molecular weight (approximately 89 kDa, though observed sizes vary from 70-110 kDa)

Enhanced Validation Approaches:

• Orthogonal strategies: Comparing results using antibodies targeting different CLCN7 epitopes

• Independent detection methods: Correlating antibody results with mRNA expression or mass spectrometry data

• Tissue/cell expression pattern consistency: CLCN7 should be detected in tissues known to express the protein (brain, kidney, small intestine)

Manufacturer Validation Data:

• Review available validation data: Some suppliers, like Atlas Antibodies, provide extensive validation through the Human Protein Atlas project

• This includes testing on tissue arrays of 44 normal human tissues and 20 common cancer types

• Cross-check observed staining patterns with expected subcellular localization (lysosomal/punctate cytoplasmic pattern)

Protocol Controls:

• Include appropriate positive controls: Tissues or cell lines with known CLCN7 expression

• Use proper negative controls: Primary antibody omission, isotype controls, and non-expressing tissues

• Verify signal specificity across different applications (WB, IHC, IF) when possible

By implementing multiple validation strategies, researchers can establish confidence in antibody specificity and generate more reliable and reproducible CLCN7 research data.

How can CLCN7 antibodies contribute to understanding the pathophysiology of osteopetrosis and related bone disorders?

CLCN7 antibodies serve as essential tools for elucidating the molecular mechanisms of osteopetrosis and related bone disorders, enabling various investigative approaches:

Cellular Mechanisms of Bone Remodeling:

• CLCN7 antibodies help visualize protein expression in osteoclasts, where it plays a critical role in bone resorption

• Defects in CLCN7 function lead to osteopetrosis due to impaired osteoclast activity

• Immunohistochemical studies using CLCN7 antibodies can assess protein localization in bone tissue samples from patients and disease models

Genotype-Phenotype Correlations:

• Different mutations in CLCN7 are associated with varying disease severity and inheritance patterns:

  • Autosomal recessive osteopetrosis type 4 (OPTB4/infantile malignant osteopetrosis type 2)

  • Autosomal dominant osteopetrosis type 2 (OPTA2/Albers-Schönberg disease)

• CLCN7 antibodies help correlate protein expression levels and localization with specific mutations and disease phenotypes

Therapeutic Development:

• CLCN7 antibodies can monitor protein expression during drug screening efforts

• For dominant negative mutations, therapies aimed at enhancing remaining wild-type CLCN7 function can be assessed

• For recessive mutations, gene therapy or bone marrow transplantation outcomes can be evaluated at the protein level

Model System Validation:

• CLCN7 antibodies help validate disease models by confirming altered protein expression or localization

• In mouse models of CLCN7 mutations, antibodies confirm that the phenotype correlates with expected protein changes

• Patient-derived cell lines can be characterized using CLCN7 antibodies to confirm they recapitulate disease mechanisms

Functional Studies:

• Recent research has expanded our understanding beyond classical osteopetrosis to include non-skeletal manifestations of CLCN7 dysfunction

• The discovery that gain-of-function mutations (like Y715C) can cause a syndrome without osteopetrosis but with hypopigmentation, organomegaly, and developmental delay highlights the complex role of CLCN7

• CLCN7 antibodies have been instrumental in characterizing these novel phenotypes and understanding how different mutations affect protein function

Through these applications, CLCN7 antibodies continue to advance our understanding of bone disorders and expand the known spectrum of CLCN7-related diseases.

What insights have been gained about lysosomal storage disorders using CLCN7 antibodies in recent research?

Recent research using CLCN7 antibodies has provided significant insights into lysosomal storage disorders and expanded our understanding of CLCN7's role beyond bone homeostasis:

Novel Disease Associations:

• CLCN7 antibodies helped identify a previously unrecognized syndrome associated with gain-of-function CLCN7 variants

• This condition, characterized by hypopigmentation, organomegaly, and delay in development (HOD syndrome), represents a new category of lysosomal storage disorder

• Immunofluorescence and Western blot analysis with CLCN7 antibodies revealed abnormal vacuole formation in patient fibroblasts

Lysosomal pH Regulation Mechanisms:

• Studies using CLCN7 antibodies have clarified the protein's role in lysosomal pH regulation

• Research demonstrated that CLCN7 functions as a Cl⁻/H⁺ antiporter comprising the predominant Cl⁻ permeability pathway in lysosomes

• Even subtle pH changes (approximately 0.2 units) can profoundly affect lysosomal function and cellular processes

Cellular Pathology Characterization:

• Electron microscopy combined with CLCN7 immunolabeling revealed pathologically enlarged single- and double-membrane cytoplasmic vacuoles containing debris in cells with gain-of-function mutations

• These vacuoles were reminiscent of lysosomes, suggesting impaired lysosomal degradation

• Recent studies by Bose et al. (2023) using CLCN7 antibodies demonstrated that gain-of-function variants lead to:

  • Enlarged cytoplasmic vacuoles derived from endo-lysosomes

  • Defective proteolytic capacity

  • Impaired autophagic clearance with increased LC3-II and p62 markers

Cross-System Effects:

• CLCN7 antibody research has revealed unexpected connections between lysosomal dysfunction and diverse phenotypes:

  • Hypopigmentation: Linked to melanosome dysfunction due to altered pH

  • Immune dysfunction: Hypogammaglobulinemia observed in patients with gain-of-function variants

  • Neurological effects: Developmental delays and myelination abnormalities

Therapeutic Insights:

• CLCN7 antibody-based research demonstrated that chloroquine, a lysosomotropic alkalinizing agent, could reverse cellular phenotypes in gain-of-function mutations

• This finding provided proof-of-concept for pH modulation as a therapeutic approach for certain CLCN7-related disorders

• The dose-dependent nature of this effect was characterized through antibody-based detection of vacuolar phenotypes

These insights highlight how CLCN7 antibodies have contributed to our understanding of lysosomal biology and pathology beyond the classical association with osteopetrosis.

How can researchers design comprehensive experimental approaches using CLCN7 antibodies to investigate both loss-of-function and gain-of-function disease mechanisms?

Designing comprehensive experimental approaches to investigate both loss-of-function and gain-of-function CLCN7 disease mechanisms requires strategic use of antibodies within a broader experimental framework:

Parallel Model Systems Analysis:

Comprehensive Functional Assessment:

• Protein Expression and Localization:

  • Western blot analysis to quantify total CLCN7 protein levels

  • Immunofluorescence to assess subcellular localization (lysosomes vs. mislocalization)

  • Co-localization studies with OSTM1 (obligatory β-subunit) to assess complex formation

• Lysosomal Function Characterization:

  • Combined antibody labeling with pH-sensitive dyes to correlate CLCN7 presence with lysosomal pH

  • Assessment of lysosomal enzyme activity in parallel with CLCN7 detection

  • Autophagy marker (LC3-II, p62) analysis in relation to CLCN7 expression

• Tissue-Specific Manifestations:

  • Immunohistochemistry across multiple tissues (brain, bone, kidney, immune cells)

  • Correlation of protein expression patterns with tissue-specific phenotypes

  • Analysis of CLCN7 in melanocytes to investigate hypopigmentation mechanisms

Intervention Studies:

• Treatment with chloroquine or other pH modulators, followed by antibody-based assessment of cellular phenotypes

• Gene correction or complementation studies with wild-type CLCN7, monitored via antibody detection

• siRNA rescue experiments comparing knockdown and replacement with wild-type vs. mutant proteins

Translational Approaches:

• Development of high-content screening assays using CLCN7 antibodies to identify therapeutic compounds

• Patient sample analysis to correlate CLCN7 expression patterns with clinical outcomes

• Longitudinal studies in animal models with repeated antibody-based tissue analysis

Technical Considerations:

• Use multiple antibodies targeting different CLCN7 epitopes to verify results

• Include appropriate controls for each disease mechanism:

  • Heterozygous carriers for recessive conditions

  • Age-matched controls for developmental phenotypes

  • Related family members for genetic studies