CREM Antibody

What is CREM and why is it important in research?

CREM (cAMP responsive element modulator) is a transcription factor that plays crucial roles in numerous cellular processes. It belongs to the same family as CREB and ATF, though it demonstrates lower sequence homology with these proteins (67% and 57%, respectively) . CREM is widely expressed in almost all normal human tissues and exists in multiple isoforms (at least 29 documented variants) . Research interest in CREM has intensified due to its involvement in immunological pathways, including T cell responses in asthma and allergic conditions, as well as autoimmune diseases like SLE . Understanding CREM function is critical for elucidating transcriptional regulation in both physiological and pathological contexts.

What applications are CREM antibodies suitable for?

CREM antibodies can be utilized across multiple experimental applications. The 12131-1-AP CREM antibody, for example, has been validated for Western Blot (WB), Immunoprecipitation (IP), Immunofluorescence (IF), Immunohistochemistry (IHC), and ELISA applications . Each application requires specific optimization, with recommended dilutions varying by technique. For Western Blotting, a dilution range of 1:200-1:1000 is suggested; for Immunoprecipitation, 0.5-4.0 μg antibody per 1.0-3.0 mg of total protein lysate; and for Immunohistochemistry, dilutions between 1:400-1:1600 . It's important to note that optimal dilutions should be determined empirically for each experimental system to achieve the best signal-to-noise ratio.

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

Proper storage and handling of CREM antibodies are crucial for maintaining their activity and specificity. Based on manufacturer recommendations, CREM antibodies should be stored at -20°C, where they typically remain stable for one year after shipment . Most commercial CREM antibodies are supplied in PBS buffer containing 0.02% sodium azide and 50% glycerol at pH 7.3 . For smaller antibody quantities (20 μl), preparations may contain 0.1% BSA for additional stability . Importantly, aliquoting is generally unnecessary for -20°C storage of these antibody preparations due to the presence of glycerol, which prevents freeze-thaw damage . When working with the antibody, avoid repeated freeze-thaw cycles and maintain cold chain practices during experimental procedures to preserve antibody functionality.

What controls should be included when using CREM antibodies?

Proper controls are essential for validating CREM antibody specificity. For Western blotting, positive controls should include rat testis tissue, where CREM is known to be expressed . For immunoprecipitation experiments, mouse testis tissue serves as an appropriate positive control . For immunohistochemistry, human prostate cancer tissue has been validated as a positive control . Negative controls might include samples where CREM expression is downregulated through siRNA treatment, as demonstrated in validation studies with human skin melanoma CHL-1, human embryonic kidney HEK-293, and prostate cancer PC-3 cell lines . Including isotype controls (using non-specific IgG from the same species as the primary antibody) is also recommended to account for non-specific binding. For definitive validation, researchers can conduct knockdown experiments using CREM-targeting siRNA to confirm antibody specificity .

How can I properly validate a new CREM antibody for my research?

Thorough validation of CREM antibodies is critical before using them in experiments. A comprehensive validation approach includes multiple methods:

• Western blotting verification: Test the antibody on cell lysates from relevant tissues (e.g., testis) or cell lines known to express CREM. The antibody should detect bands at the expected molecular weights of approximately 37, 30, and 20 kDa, corresponding to different CREM isoforms .

• siRNA knockdown: Treat cells with CREM-targeting siRNA and control siRNA, then perform Western blotting to confirm decreased band intensity in knockdown samples .

• Immunofluorescence validation: For antibodies intended for IF applications, compare staining patterns between control and CREM-knockdown cells.

• Cross-reactivity assessment: Evaluate potential cross-reactivity with related proteins such as CREB and ATF, particularly if working in systems where these proteins are abundantly expressed .

• Literature comparison: Compare your findings with published research using the same or similar antibodies to ensure consistency of results.

For example, the CREM monoclonal antibody (clone 3B) was validated by demonstrating that it detected specific bands in control cell lysates that were diminished after CREM siRNA treatment, confirming its specificity for CREM protein .

How can CREM antibodies be used to study transcriptional regulation mechanisms?

CREM antibodies are powerful tools for investigating transcriptional regulatory mechanisms through chromatin immunoprecipitation (ChIP) assays. These experiments can reveal direct binding of CREM to gene promoters and enhancers. For example, researchers have used ChIP assays with anti-CREMα antibodies to demonstrate direct binding of CREM to the promoters of cytokine genes including IL-4 and IL-13 , as well as IL-17A .

For ChIP experiments, researchers typically use 1-2 million cells (either total human T cell suspension or activated naïve human CD4+ cells) following standard ChIP protocols from manufacturers like Upstate Biotechnology/Millipore . After chromatin fragmentation and immunoprecipitation with anti-CREM antibodies, qPCR can be performed to quantify CREM binding to specific genomic regions. Additionally, sequential ChIP (re-ChIP) can be employed to examine co-occupancy of CREM with other transcription factors or epigenetic modifiers at specific genomic loci, providing insights into complex transcriptional regulation mechanisms.

What is the significance of CREM in T cell-mediated immune responses and how can antibodies help investigate this?

CREM plays a complex role in T cell-mediated immune responses, with significant implications for allergic and autoimmune diseases. Research has demonstrated that T cells from asthmatic children and PBMCs from adults with atopy express lower mRNA levels of CREM compared to healthy controls . Mechanistically, CREM can directly bind to the IL-4 and IL-13 promoters and affect IL-2 dependent STAT5 activation, thereby regulating the TH2 response .

To investigate these processes, researchers can employ CREM antibodies in several methodologies:

• Western blotting: To compare CREM protein expression levels between healthy and disease-associated T cells.

• ChIP assays: To quantify CREM binding to cytokine promoters (IL-4, IL-13) under different conditions.

• Co-immunoprecipitation: To identify protein-protein interactions between CREM and other transcriptional regulators or signaling molecules.

• Flow cytometry: When combined with intracellular cytokine staining, this can correlate CREM expression with cytokine production at the single-cell level.

These approaches have revealed that CREM deficiency in murine T cells results in enhanced TH2 effector cytokines both in vitro and in vivo, and CREM−/− mice demonstrate stronger airway hyperresponsiveness in an OVA-induced asthma model .

How can CREM antibodies be utilized to study epigenetic modifications in gene regulation?

CREM antibodies can be integrated into epigenetic studies through several sophisticated approaches. Research has shown that CREMα can induce IL-17A expression not only through direct transcriptional activation but also via epigenetic modifications . To investigate these mechanisms, researchers can combine CREM antibodies with antibodies targeting specific histone modifications or DNA methylation markers in sequential ChIP experiments.

For example, studies have used anti-HDAC1, anti-H3K18ac, and anti-H3K27me3 antibodies alongside anti-CREM antibodies to examine the relationship between CREM binding and chromatin modifications . This approach can reveal whether CREM recruitment correlates with changes in histone acetylation (often associated with active transcription) or histone methylation (which can be associated with either activation or repression depending on the specific modification).

Additionally, CREM antibodies can be used in combination with DNA methylation studies (such as bisulfite sequencing or methylation-specific PCR) to examine whether CREM binding affects the DNA methylation status of target promoters, potentially providing insights into long-term gene regulation mechanisms.

What considerations are important when detecting different CREM isoforms using antibodies?

CREM exists in multiple isoforms, which presents challenges for comprehensive detection. When selecting CREM antibodies for isoform analysis, researchers should consider the following:

• Epitope location: Antibodies targeting the DNA-binding domain, which is present in most CREM isoforms, provide broader detection. For example, the monoclonal anti-human CREM antibody (clone 3B) targets amino acids 201-300, which includes the DNA-binding domain and can detect 28 of 29 CREM isoforms with 85-100% sequence identity .

• Expected molecular weights: Different CREM isoforms appear at distinct molecular weights on Western blots, typically around 37, 30, and 20 kDa . Researchers should be familiar with the expected pattern for their experimental system.

• Isoform-specific detection: For studies focusing on specific isoforms, custom antibodies targeting unique regions may be necessary.

• Validation across isoforms: When validating antibodies, researchers should confirm detection of relevant isoforms in their experimental system using positive controls known to express specific variants.

• Complementary approaches: Combining antibody-based detection with RT-PCR using isoform-specific primers can provide more comprehensive analysis of CREM expression.

How can CREM antibodies be applied in fusion protein detection, particularly in cancer research?

CREM antibodies can be valuable tools for detecting CREM fusion proteins in cancer research. For instance, the EWSR1-CREM fusion has been identified in certain malignancies. When investigating fusion proteins, several methodological considerations are important:

• Molecular weight analysis: Fusion proteins typically display different molecular weights than wild-type proteins. The EWSR1-CREM fusion protein appears at approximately 55 kDa, distinct from wild-type CREM (≈37, 30, and 20 kDa) .

• Dual antibody approach: Using antibodies against both fusion partners (e.g., anti-CREM and anti-EWSR1) with different fluorescent labels allows co-localization analysis to confirm fusion protein identity .

• siRNA validation: Knockdown experiments targeting one fusion partner can help validate specificity, as demonstrated in the CHL-1 cell line where CREM siRNA treatment reduced the intensity of the fusion protein band .

• Clinical application potential: CREM antibodies may have diagnostic value in identifying certain malignancies associated with CREM rearrangements, such as mucoepidermoid carcinoma (MEC) .

For optimal detection of fusion proteins, researchers should optimize Western blotting conditions, including gel percentage, transfer time, and blocking reagents, to maximize sensitivity for higher molecular weight proteins while maintaining specificity.

What are common issues encountered when using CREM antibodies in Western blotting and how can they be resolved?

Western blotting with CREM antibodies may present several challenges. Here are common issues and their solutions:

For optimal results, follow the manufacturer's recommended Western blotting protocol, using rat testis tissue as a positive control when validating the system .

What strategies can improve immunohistochemistry results when using CREM antibodies?

Successful immunohistochemistry (IHC) with CREM antibodies requires careful optimization. Consider these strategies:

• Antigen retrieval optimization: For CREM antibodies, heat-induced epitope retrieval using TE buffer at pH 9.0 is recommended. Alternatively, citrate buffer at pH 6.0 may be used . The optimal retrieval method should be determined empirically for each tissue type.

• Titration of antibody concentration: Begin with the recommended dilution range of 1:400-1:1600 , then optimize based on signal-to-noise ratio in your specific tissue samples.

• Use validated positive controls: Human prostate cancer tissue has been validated for CREM IHC . Including this control helps confirm proper staining technique.

• Signal amplification systems: For tissues with low CREM expression, consider using polymer-based detection systems or tyramide signal amplification.

• Counterstaining optimization: Adjust hematoxylin counterstaining intensity to provide adequate nuclear detail without obscuring CREM nuclear staining.

• Multi-step blocking protocol: To reduce background, implement a multi-step blocking protocol including hydrogen peroxide treatment, protein blocking, and avidin/biotin blocking if using biotin-based detection systems.

• Optimal fixation: Ensure tissues are properly fixed (typically 24-48 hours in 10% neutral buffered formalin) to preserve antigenic epitopes while maintaining tissue morphology.

How can the specificity of CREM antibodies be verified in experimental systems?

Verifying antibody specificity is critical for reliable results. Multiple complementary approaches should be employed:

• siRNA knockdown validation: Treat cells with CREM-targeting siRNA to reduce CREM expression. Western blot or immunofluorescence analysis should show corresponding reduction in signal intensity. This approach has been successfully used with human skin melanoma CHL-1, human embryonic kidney HEK-293, and prostate cancer PC-3 cell lines .

• Peptide competition assay: Pre-incubate the CREM antibody with excess immunizing peptide before application to samples. Specific signals should be significantly reduced or eliminated.

• Genetic models: When available, tissues or cells from CREM knockout models provide excellent negative controls.

• Immunoprecipitation-Mass Spectrometry: Perform immunoprecipitation with the CREM antibody followed by mass spectrometry to confirm that CREM is the predominant protein being detected.

• Multiple antibody comparison: Use antibodies targeting different CREM epitopes and compare staining patterns. Consistent results across antibodies increase confidence in specificity.

• Recombinant protein controls: Test antibody reactivity against purified recombinant CREM protein and related family members (CREB, ATF) to assess cross-reactivity.

How has CREM antibody technology advanced our understanding of allergic and autoimmune diseases?

Research utilizing CREM antibodies has significantly expanded our understanding of allergic and autoimmune disease mechanisms. Several key discoveries illustrate this impact:

In allergic diseases, CREM has been identified as a regulator of TH2 responses. Studies have shown that T cells from asthmatic children and PBMCs of adults with atopy express lower mRNA levels of CREM compared to healthy controls . Using CREM antibodies in ChIP assays, researchers demonstrated direct CREM binding to the IL-4 and IL-13 promoters, key cytokines in allergic responses . Furthermore, CREM deficiency in murine T cells resulted in enhanced TH2 effector cytokine production and stronger airway hyperresponsiveness in an OVA-induced asthma model .

In autoimmune conditions like systemic lupus erythematosus (SLE), CREM antibodies have revealed that CREMα binds to the proximal IL17A promoter and induces IL-17A expression through both transcriptional activation and epigenetic modifications . This finding is particularly significant as both IL-17A and CREMα expression levels are increased in T cells from SLE patients . These discoveries suggest that targeting CREM could potentially mitigate IL-17A-driven inflammatory responses in autoimmune diseases.

What role does CREM play in epigenetic regulation and how can CREM antibodies help investigate this mechanism?

CREM antibodies have been instrumental in uncovering the role of CREM in epigenetic regulation. Research has demonstrated that CREMα can influence gene expression not only through direct DNA binding but also by affecting the epigenetic landscape of target genes.

ChIP assays using CREM antibodies have shown that CREMα binding to the IL-17A promoter is associated with significant epigenetic modifications . By combining CREM ChIP with ChIP for epigenetic markers like HDAC1, H3K18ac (an activation mark), and H3K27me3 (a repression mark), researchers have been able to correlate CREM binding with specific chromatin states .

Furthermore, studies have shown that CREM can interact with DNA methyltransferases such as DNMT3a, potentially influencing DNA methylation patterns at target genes . This has been investigated using sequential ChIP (re-ChIP) experiments where chromatin is first immunoprecipitated with CREM antibodies and then with antibodies against epigenetic modifiers.

These findings highlight CREM's dual role as both a direct transcriptional regulator and an orchestrator of epigenetic modifications, providing a more comprehensive understanding of gene regulation mechanisms in immune cells and other systems.

How can CREM antibodies contribute to cancer research and potential therapeutic developments?

CREM antibodies have emerging applications in cancer research, particularly in the context of CREM fusion proteins. The EWSR1-CREM fusion has been identified in certain malignancies, including mucoepidermoid carcinoma (MEC) . By using CREM antibodies in combination with EWSR1 antibodies, researchers can detect these fusion proteins through co-localization in immunofluorescent Western blotting .

This approach has potential diagnostic value, as demonstrated in a study exploring whether CREM immunohistochemistry could serve as an indicator of the presence of the EWSR1-CREM fusion gene in low-grade mucoepidermoid carcinoma . The ability to detect CREM fusion proteins could aid in cancer classification and potentially guide treatment decisions.

Beyond fusion protein detection, CREM antibodies can help investigate altered CREM expression across various cancer types. Transcriptomic analysis of normal tissues and cancer samples has revealed differential CREM expression patterns that might correlate with disease progression or treatment response .

As our understanding of CREM's role in cellular processes expands, CREM antibodies may contribute to the development of targeted therapies by helping identify patients with specific CREM-related alterations who might benefit from particular treatment approaches.

What experimental design recommendations ensure optimal results when using CREM antibodies?

To achieve optimal results with CREM antibodies, researchers should implement these experimental design recommendations:

• Antibody selection: Choose antibodies targeting the C-terminal DNA-binding domains of CREM if broader isoform detection is desired . For isoform-specific studies, select antibodies targeting unique regions.

• Appropriate controls: For Western blotting, include rat testis tissue as a positive control . For immunoprecipitation, mouse testis tissue serves as an appropriate positive control . For immunohistochemistry, human prostate cancer tissue has been validated .

• Titration experiments: Before conducting full-scale experiments, perform antibody titration to determine optimal concentrations for your specific samples and applications.

• Validation in your system: Even with previously validated antibodies, confirm specificity in your experimental system using techniques like siRNA knockdown .

• Application-specific optimization:

  • For Western blotting: Optimize protein extraction methods to preserve CREM integrity. Begin with a dilution range of 1:200-1:1000 .

  • For immunoprecipitation: Use 0.5-4.0 μg antibody for 1.0-3.0 mg of total protein lysate .

  • For immunohistochemistry: Test both TE buffer (pH 9.0) and citrate buffer (pH 6.0) for antigen retrieval .

  • For ChIP assays: Optimize chromatin fragmentation conditions and use 1-2 million cells per immunoprecipitation .

• Complementary approaches: Combine antibody-based detection with mRNA analysis to provide a more comprehensive understanding of CREM expression and function.

What standardization procedures ensure reproducibility in CREM antibody-based experiments?

Standardization is crucial for reproducible CREM antibody experiments. Implement these procedures:

• Antibody validation documentation: Maintain detailed records of antibody validation experiments, including Western blots showing expected band patterns, knockdown studies, and positive control results.

• Standard operating procedures (SOPs): Develop and strictly follow SOPs for each application (WB, IP, IHC, ChIP), documenting all steps from sample preparation to data analysis.

• Reagent quality control: Track antibody lot numbers and perform quality control tests with each new lot to ensure consistent performance. Store antibodies according to manufacturer recommendations (-20°C, avoiding repeated freeze-thaw cycles) .

• Reference standards: Include consistent positive controls in every experiment. For Western blotting, rat testis tissue serves as an excellent reference standard .

• Quantification methods: Standardize image acquisition and quantification methods. For Western blots, use housekeeping proteins as loading controls and employ standardized densitometry protocols.

• Reporting standards: Follow field-specific reporting guidelines when publishing results, including detailed methodology sections that specify antibody catalog numbers, dilutions, incubation conditions, and validation approaches.

• Replicate design: Implement both technical replicates (same sample analyzed multiple times) and biological replicates (independent samples) to assess variability and ensure reproducibility.

• Blinding procedures: When applicable, implement blinding procedures during analysis to prevent unconscious bias in interpretation of results.

What emerging technologies might enhance the specificity and utility of CREM antibodies?

Several emerging technologies hold promise for enhancing CREM antibody applications:

• Recombinant antibody technology: Single-chain variable fragments (scFvs) or antigen-binding fragments (Fabs) directed against specific CREM epitopes could provide improved specificity and reduced background compared to conventional polyclonal antibodies.

• Proximity ligation assays (PLA): Combining CREM antibodies with PLA technology could enable visualization of CREM interactions with other proteins or DNA sequences with single-molecule resolution, providing spatial context to CREM function.

• CUT&Tag and CUT&RUN technologies: These techniques, which combine chromatin immunoprecipitation principles with tagmentation and sequencing, offer higher resolution and lower background than traditional ChIP-seq approaches for mapping CREM binding sites genome-wide.

• Nanobodies: The development of single-domain antibodies derived from camelids (nanobodies) against CREM could provide superior tissue penetration and access to epitopes that conventional antibodies cannot reach.

• BiTE (Bispecific T-cell Engager) technology: For therapeutic applications, bispecific antibodies targeting both CREM (in fusion proteins) and immune effector cells could be explored for targeted therapy approaches in relevant malignancies.

• Antibody-based proteomics: Integration of CREM antibodies into high-throughput proteomics workflows could enable systematic analysis of CREM expression and interactions across tissues, conditions, and disease states.

These technological advances could significantly expand our understanding of CREM biology and potentially lead to novel diagnostic or therapeutic applications.