Commd5 Antibody

What is COMMD5 and why is it significant in research contexts?

COMMD5, also known as HCARG or HT002, is a hypertension-related calcium-regulated gene that encodes a protein containing the COMM (Copper Metabolism MURR1) domain. The protein has a calculated molecular weight of approximately 25 kDa and is observed at the same weight in experimental settings . COMMD5 has gained significant research interest due to its involvement in renal tubular epithelial integrity and its implications in renal cell carcinoma (RCC) tumorigenesis . The protein's expression is negatively regulated by extracellular calcium concentration, with higher basal mRNA levels observed in hypertensive animal models . Research interest in COMMD5 spans multiple fields including cancer biology, cardiovascular research, and renal physiology, making antibodies against this protein critical tools for investigating its function and expression patterns.

What applications are COMMD5 antibodies validated for in research settings?

COMMD5 antibodies have been validated for multiple research applications, with documented evidence of successful use across several methodologies. According to the literature and commercially available products, COMMD5 antibodies have been successfully employed in:

• Western Blot (WB): Validated at dilutions of 1:500-1:2000 for protein expression analysis

• Immunoprecipitation (IP): Effective at concentrations of 0.5-4.0 μg for 1.0-3.0 mg of total protein lysate

• Immunofluorescence (IF)/Immunocytochemistry (ICC): Used at dilutions of 1:50-1:500

• Immunohistochemistry (IHC): Multiple publications demonstrate successful application

• Co-Immunoprecipitation (CoIP): Validated in at least two published studies

• ELISA: Demonstrated reactivity in enzyme-linked immunosorbent assays

The antibodies have also been employed successfully in knockdown/knockout validation studies, providing crucial tools for functional genomics approaches to studying COMMD5 biology .

What tissue and cell type reactivity has been documented for COMMD5 antibodies?

COMMD5 antibodies have demonstrated consistent reactivity across various tissues and cell types. Western blot analysis has successfully detected COMMD5 in:

Immunoprecipitation has been specifically validated in mouse heart tissue, while immunofluorescence/immunocytochemistry applications have been confirmed in HeLa cells . This broad reactivity profile makes these antibodies versatile tools for investigating COMMD5 expression across multiple experimental models and physiological systems.

How should researchers optimize Western blot protocols for COMMD5 detection?

When designing Western blot experiments for COMMD5 detection, researchers should consider several optimization strategies based on published protocols:

For sample preparation, cells should be lysed in modified radioimmunoprecipitation assay (RIPA) buffer (150 mM NaCl, 1 mM EDTA, 1% NP-40, 0.25% Na-deoxycholate, 50 mM Tris-HCl, pH 7.4, 1 mM Na₃VO₄, 1 mM NaF, and 1 mM phenylmethylsulfonyl fluoride) supplemented with protease inhibitors . The freeze/thaw method followed by trituration and centrifugation has been documented to effectively extract COMMD5.

For the blotting procedure:

• Mix total proteins with sample buffer containing 4% SDS, 20% glycerol, and 10% 2-mercaptoethanol

• Heat samples to 95°C for 5 minutes

• Load equal amounts of protein onto 8-15% polyacrylamide gels

• Transfer to polyvinylidene difluoride (PVDF) membranes

• Block membranes appropriately (blocking conditions should be optimized)

• Incubate overnight with anti-COMMD5 primary antibody (recommended dilution 1:500-1:2000)

• Incubate with horseradish peroxidase-conjugated secondary antibodies for 60 minutes

• Visualize using enhanced chemiluminescence

• Normalize expression levels to GAPDH or other appropriate housekeeping proteins

For antibody selection, researchers should note that multiple COMMD5 antibodies are available, including rabbit polyclonal antibodies that have been validated for human and mouse samples .

What are the critical parameters for immunofluorescence experiments using COMMD5 antibodies?

Successful immunofluorescence experiments with COMMD5 antibodies require attention to several methodological details:

For cell fixation and permeabilization, researchers have two documented options:

• For co-staining with E-cadherin: Fix and permeabilize cells in cold methanol

• For co-staining with α-SMA: Fix cells in 4% paraformaldehyde and permeabilize with 0.2% Triton-X-100 in phosphate-buffered saline (PBS)

The blocking stage is crucial to reduce background staining. After fixation and permeabilization, thorough blocking should be performed before primary antibody incubation. The recommended antibody dilution range for immunofluorescence is 1:50-1:500, though researchers should optimize this for their specific application .

For visualization, secondary antibodies appropriate to the host species of the primary antibody should be used, followed by mounting with a medium containing DAPI for nuclear counterstaining . Fluorescence microscopy (such as that performed on an Olympus IX73) has been successfully used to visualize COMMD5 staining patterns .

It's important to note that sample-dependent factors may affect results, and researchers are advised to titrate the antibody in each testing system to obtain optimal results .

How can COMMD5 antibodies be employed to investigate its role in renal cell carcinoma?

COMMD5 antibodies have been instrumental in elucidating the protein's contrasting role in renal cell carcinoma (RCC), where it appears to function as both a tumor suppressor and promoter depending on context. For comprehensive investigation of COMMD5's role in RCC, researchers should consider a multi-faceted approach:

For tissue expression studies:
Immunohistochemical staining of RCC and renal cortex specimens can be performed by incubating sections overnight with anti-COMMD5 antibody, followed by visualization using appropriate staining kits . The COMMD5 staining index can be calculated as the product of staining intensity and percentage of positive area (typically on a range of 1-4), with expression levels classified into low (indexes 1-2) and high (3-4) expression groups .

For functional studies in cell lines:

• Generate stable cell lines overexpressing COMMD5 (e.g., COMMD5-Renca cells) alongside control cells (e.g., Neo-Renca)

• Use COMMD5 antibodies in Western blotting to confirm overexpression

• Perform immunostaining to examine expression and localization of epithelial markers (E-cadherin) and mesenchymal markers (α-SMA) to assess epithelial-mesenchymal transition

• Correlate COMMD5 expression with cellular phenotypes using functional assays:

  • Cell proliferation and viability (WST-1 assay)

  • Cell invasion (CytoSelect™ invasion assay)

  • Cell adhesion (fluorescence-based adhesion assays)

For in vivo metastasis models:
COMMD5 antibodies can be used to analyze protein expression in experimental metastasis models, where cells with differential COMMD5 expression are injected into animal models (e.g., BALB/c mice) to assess metastatic potential .

For clinical correlation studies:
Researchers can combine COMMD5 immunohistochemistry data with clinical characteristics and outcome data to generate Kaplan-Meier survival curves, examining the relationship between COMMD5 expression and metastasis-free survival .

What methodological approaches should be used when analyzing COMMD5 expression across different tissue types?

Analysis of COMMD5 expression across tissue types requires careful methodological consideration to ensure accurate and reproducible results:

Tissue preparation:
For optimal immunohistochemical detection, tissues should be properly fixed (typically in formalin or Tissuefix), embedded in paraffin, and sectioned at appropriate thickness (approximately 3-5 μm) . For animal studies, various organs should be harvested following standardized protocols to ensure consistency.

Standardized staining protocol:
A standardized staining protocol should be established to allow for comparison across tissue types. This generally involves:

• Deparaffinization and rehydration of sections

• Antigen retrieval (method may need optimization for different tissue types)

• Blocking of endogenous peroxidase activity and non-specific binding

• Overnight incubation with anti-COMMD5 antibody at a consistent dilution

• Incubation with secondary antibody and detection system

• Counterstaining, typically with hematoxylin

• Dehydration and mounting

Quantification methods:
For accurate comparison across tissue types, standardized quantification methods should be employed:

• Staining index calculation (product of intensity and percentage of positive area)

• Digital image analysis for more objective quantification

• Blinded assessment by pathologists to avoid bias

Validation using multiple detection methods:
To confirm tissue expression patterns, researchers should validate immunohistochemistry findings using complementary techniques:

• Western blotting of tissue lysates

• qPCR analysis of mRNA expression

• In situ hybridization to localize transcript expression

Positive control tissues with known COMMD5 expression (e.g., kidney, heart, stomach) should be included in analyses, as these have demonstrated consistent COMMD5 reactivity in previous studies .

How can researchers address non-specific binding issues with COMMD5 antibodies?

Non-specific binding can significantly impact the interpretation of COMMD5 antibody results. Researchers can implement several strategies to minimize this issue:

Optimal antibody dilution determination:
The recommended dilution ranges (1:500-1:2000 for WB, 1:50-1:500 for IF/ICC) should be used as starting points, with subsequent titration experiments to determine the optimal concentration that maximizes specific signal while minimizing background .

Blocking optimization:
Experiment with different blocking agents (BSA, normal serum, commercial blocking solutions) and concentrations to identify the most effective blocking protocol for your specific tissue or cell type. Extended blocking times (1-2 hours at room temperature or overnight at 4°C) may be necessary for certain applications.

Negative controls:
Include appropriate negative controls in all experiments:

• Primary antibody omission

• Isotype control antibodies

• Tissues or cells known to be negative for COMMD5 expression

• When possible, COMMD5 knockout or knockdown samples

Validation through multiple techniques:
Confirm antibody specificity by comparing results across multiple techniques (WB, IP, IF, IHC) and ensuring consistent detection of the expected 25 kDa protein .

Sample preparation considerations:

• For IF/ICC: Optimize fixation and permeabilization methods (methanol vs. paraformaldehyde/Triton-X-100) depending on subcellular localization and epitope accessibility

• For WB: Ensure complete protein denaturation and reduction; consider alternative lysis buffers if signal is weak

• For IHC: Test multiple antigen retrieval methods (heat-induced vs. enzymatic, different pH conditions)

Storage and handling:
Store antibodies according to manufacturer recommendations (-20°C with 0.02% sodium azide and 50% glycerol pH 7.3) and avoid repeated freeze-thaw cycles . Antibodies should be stable for one year after shipment when stored properly.

What are the critical variables in co-immunoprecipitation experiments involving COMMD5?

Co-immunoprecipitation (Co-IP) experiments with COMMD5 antibodies require careful optimization to successfully identify protein-protein interactions. Key variables to consider include:

Antibody amount and quality:
Use 0.5-4.0 μg of COMMD5 antibody for immunoprecipitation of 1.0-3.0 mg of total protein lysate . The antibody should be of high quality and validated specifically for IP applications.

Lysis conditions:
The choice of lysis buffer significantly impacts Co-IP success:

• For maintaining protein-protein interactions, use milder non-ionic detergents (e.g., NP-40, Triton X-100) rather than ionic detergents (SDS, deoxycholate)

• Include protease inhibitors to prevent degradation

• Consider phosphatase inhibitors if studying phosphorylation-dependent interactions

• The modified RIPA buffer described in literature (150 mM NaCl, 1 mM EDTA, 1% NP-40, 0.25% Na-deoxycholate, 50 mM Tris-HCl, pH 7.4) supplemented with protease inhibitors has been successfully used in COMMD5 studies

Binding conditions:
Optimization of binding conditions is essential:

• Duration: Typically overnight at 4°C with gentle rotation

• Buffer composition: Salt concentration and pH can affect specificity

• Pre-clearing step: To reduce non-specific binding, pre-clear lysates with protein A/G beads

Washing stringency:
Balancing thorough washing to remove non-specific binding with maintaining specific interactions is critical:

• Number of washes (typically 3-5)

• Wash buffer composition (salt concentration, detergent type and amount)

• Duration of washes

Elution methods:
Different elution strategies can be employed:

• Denaturing conditions with SDS sample buffer (most common)

• Competitive elution with peptides

• Acid elution

Controls:
Include appropriate controls:

• IgG control from the same species as the COMMD5 antibody

• Input sample (pre-immunoprecipitation)

• Reverse Co-IP (using antibodies against suspected interacting partners)

• Negative control samples (tissues/cells with low or no COMMD5 expression)

Successful Co-IP experiments with COMMD5 antibodies have been documented in published literature, providing validation for this approach in identifying COMMD5 protein interaction networks .

How is COMMD5 antibody research contributing to our understanding of cancer metastasis?

COMMD5 antibody-based research has revealed complex roles for this protein in cancer progression and metastasis, particularly in renal cell carcinoma (RCC). Experimental approaches using COMMD5 antibodies have demonstrated:

Contrasting roles in tumor progression:
Immunohistochemical analysis of RCC patient samples using COMMD5 antibodies has revealed that COMMD5 expression levels correlate with clinical outcomes, suggesting context-dependent roles in cancer progression . Researchers have used standardized staining indexes to classify tumors into high and low COMMD5 expression groups, allowing for correlation with metastasis-free survival.

Effects on tumor cell invasiveness:
Cell invasion assays with COMMD5-overexpressing cells (validated by antibody staining) have revealed that COMMD5 can modulate cancer cell invasiveness. The CytoSelect™ invasion assay approach has been successfully employed to quantify the impact of COMMD5 on the invasive properties of cancer cells .

Impact on cellular adhesion:
COMMD5 antibody research has demonstrated that this protein influences cellular adhesion properties, a critical component of the metastatic cascade. Fluorescence-based adhesion assays have been used to measure how COMMD5 expression levels affect cell-substrate interactions .

Regulation of epithelial-mesenchymal transition (EMT):
Antibody-based detection of epithelial markers (E-cadherin) and mesenchymal markers (α-SMA) in cells with altered COMMD5 expression has revealed that COMMD5 may regulate the EMT process, which is fundamental to cancer metastasis . This has been demonstrated through dual immunofluorescence staining approaches.

In vivo metastasis models:
Experimental metastasis assays using cells with altered COMMD5 expression (confirmed by antibody staining) have shown that COMMD5 can influence metastatic potential in animal models. Histological analysis of metastatic nodules, including measurements of nodule number and size, has provided quantitative assessment of COMMD5's impact on metastasis .

Future research directions utilizing COMMD5 antibodies in cancer metastasis studies might include single-cell analysis of COMMD5 expression in heterogeneous tumors, investigation of post-translational modifications of COMMD5 in metastatic versus non-metastatic cells, and exploration of COMMD5's role in the tumor microenvironment.

What are the methodological considerations when investigating COMMD5's role in hypertension research?

COMMD5 has been identified as a hypertension-related calcium-regulated gene , making it a target of interest in cardiovascular research. When designing experiments to investigate COMMD5's role in hypertension, researchers should consider these methodological approaches:

Expression analysis in hypertensive models:

• Utilize COMMD5 antibodies for comparative protein expression analysis in normotensive versus hypertensive animal models

• Apply standardized Western blotting protocols with appropriate normalization to housekeeping proteins

• Consider tissue-specific expression patterns, with particular focus on cardiovascular and renal tissues where COMMD5 is known to be expressed

Calcium regulation studies:
Given that COMMD5 is negatively regulated by extracellular calcium concentration , experimental designs should include:

• Calcium challenge experiments with varying extracellular calcium concentrations

• Time-course studies to determine the kinetics of COMMD5 regulation by calcium

• Analysis of calcium-dependent signaling pathways potentially involved in COMMD5 regulation

Functional studies in relevant cell types:

• Vascular smooth muscle cells, endothelial cells, and renal tubular cells should be considered as relevant models

• Overexpression and knockdown/knockout approaches with COMMD5 antibody validation

• Measurements of cellular responses relevant to hypertension (contractility, calcium handling, response to vasoactive substances)

In vivo experimental approaches:

• COMMD5 expression analysis in tissues from hypertensive animals and humans

• Correlation of COMMD5 levels with blood pressure measurements and other cardiovascular parameters

• Genetic models with altered COMMD5 expression to directly assess its impact on blood pressure regulation

Clinical correlation studies:

• Analysis of COMMD5 expression in human samples from normotensive and hypertensive individuals

• Correlation of COMMD5 levels with clinical parameters, medication response, and long-term outcomes

• Genetic association studies examining COMMD5 polymorphisms and hypertension risk

Researchers should note that while COMMD5 has been linked to hypertension, the exact mechanisms remain under investigation, requiring careful experimental design with appropriate controls and validation using multiple complementary techniques, with COMMD5 antibodies serving as key tools in these investigations.