CCNE2 Antibody

What is CCNE2 and what is its biological function?

CCNE2 (Cyclin E2) is a member of the highly conserved cyclin family that plays a crucial role in cell cycle regulation. It forms a complex with and functions as a regulatory subunit of CDK2 (Cyclin-Dependent Kinase 2) and specifically interacts with CIP/KIP family of CDK inhibitors . CCNE2 is a key regulator of cell cycle progression, promoting cell cycle entry and progression through the G1/S phase transition . It is involved in the control of DNA replication and has been implicated in numerous cellular processes related to cell division. Dysregulation of CCNE2 has been linked to various cancers, making it a promising target for cancer research and drug development .

What applications are CCNE2 antibodies suitable for?

CCNE2 antibodies are versatile tools that can be used in multiple experimental applications. Based on validated research data, CCNE2 antibodies can be reliably used in:

The selection of application should be based on your specific research question and experimental design requirements .

What species reactivity can I expect from commonly available CCNE2 antibodies?

Commercial CCNE2 antibodies demonstrate varying species reactivity profiles. Based on available data:

• Most CCNE2 antibodies show confirmed reactivity to human samples

• Many also react with mouse samples

• Some antibodies have predicted reactivity to rat samples based on sequence homology

It's important to note that while sequence homology may predict cross-reactivity, actual performance should be validated experimentally in your specific model system. For instance, some antibodies share 100% sequence homology with certain species but reactivity has not been explicitly confirmed by the manufacturer .

How should CCNE2 antibodies be stored and handled to maintain optimal performance?

For long-term storage and maximum stability:

• Store antibodies at -20°C for up to one year

• For frequent use and short-term storage (up to one month), 4°C is recommended

• Some formulations contain 50% glycerol with PBS and 0.02% sodium azide at pH 7.3

• Avoid repeated freeze-thaw cycles as they can compromise antibody performance

• For antibodies supplied in small volumes (e.g., 20μl), some manufacturers note that aliquoting is unnecessary for -20°C storage

Following these storage guidelines will help maintain antibody specificity and sensitivity over time, ensuring consistent experimental results.

How can I optimize Western blotting protocols for CCNE2 detection?

Optimizing Western blot protocols for CCNE2 requires attention to several critical parameters:

• Sample preparation: CCNE2 is a cell cycle-regulated protein with variable expression levels. Consider synchronizing cells at G1/S boundary for maximum expression.

• Expected molecular weight: CCNE2 should be detected at approximately 48 kDa on Western blots, though slight variations may occur due to post-translational modifications .

• Recommended dilutions: Start with a 1:1000 dilution for most CCNE2 antibodies, adjusting based on signal intensity .

• Blocking conditions: Use 5% non-fat dry milk in TBST for initial trials, though BSA may provide lower background in some cases.

• Troubleshooting multiple bands:

  • If detecting multiple bands, consider cell cycle stage as CCNE2 may exhibit modified forms

  • Post-translational modifications like phosphorylation at Thr62, Ser88, Ser72, Thr380, and Ser384 sites can affect migration patterns

  • These modifications are regulated by kinases including CDK2 and GSK-3

• Controls: Include known positive controls (e.g., Jurkat cell lysate) and negative controls to validate specificity.

For challenging samples, titration of both primary and secondary antibodies may be necessary to achieve optimal signal-to-noise ratio.

What are the critical considerations for immunohistochemical detection of CCNE2?

Successful immunohistochemical detection of CCNE2 requires attention to tissue preparation and antigen retrieval:

• Antigen retrieval methods: Two validated approaches have shown success:

  • TE buffer pH 9.0 (recommended primary method)

  • Citrate buffer pH 6.0 (alternative method)

• Tissue-specific considerations:

  • Human breast cancer tissue and mouse testis tissue have been validated as positive controls

  • CCNE2 typically shows nuclear localization with potential cytoplasmic staining

  • Expression varies by tissue type and cell cycle stage

• Dilution optimization: Begin with 1:400 dilution and adjust through titration experiments

• Signal amplification: For tissues with low expression, consider using polymer-based detection systems for signal enhancement

• Specificity validation: Confirm staining pattern with antibodies from different clones/manufacturers to rule out non-specific binding

• Counterstaining optimization: Adjust counterstain intensity to provide adequate nuclear detail without masking CCNE2 signal

When interpreting results, consider that CCNE2 expression is cell cycle-dependent and varies between proliferating and quiescent cells.

How can I perform multiplexed detection of CCNE2 with other cell cycle markers?

Multiplexed detection of CCNE2 with other cell cycle proteins provides valuable insights into cell cycle dynamics:

• Compatible antibody pairs: When designing multiplexed experiments, consider:

  • Select antibodies raised in different host species (e.g., rabbit anti-CCNE2 with mouse anti-CDK2)

  • For same-species antibodies, use directly conjugated primary antibodies with distinct fluorophores

  • Verify that epitopes don't overlap when studying protein complexes (e.g., CCNE2-CDK2)

• Sequential immunostaining protocol:

  • Begin with the weakest signal antibody first

  • For CCNE2 detection in immunofluorescence, a dilution of 1:200-1:800 is recommended

  • Include appropriate blocking steps between antibody applications

  • Validate that secondary antibodies don't cross-react

• Recommended marker combinations:

  • CCNE2 + CDK2: To assess complex formation

  • CCNE2 + Ki-67: To correlate with proliferation status

  • CCNE2 + Cyclin A: To delineate G1/S transition

  • CCNE2 + phospho-Rb: To evaluate downstream pathway activation

• Imaging considerations:

  • Use sequential scanning for confocal microscopy to prevent bleed-through

  • Include single-stained controls for spectral unmixing

  • Quantify co-localization using appropriate statistical methods and software

This approach enables comprehensive analysis of CCNE2 function within the broader context of cell cycle regulation.

What are the considerations for flow cytometric analysis of CCNE2?

Flow cytometric analysis of CCNE2 requires specific optimization for intracellular detection:

• Cell preparation and fixation:

  • Use 4% paraformaldehyde fixation (10-15 minutes at room temperature)

  • Permeabilize with 0.1-0.5% Triton X-100 or commercial permeabilization buffers

  • Include RNase treatment if performing DNA content analysis simultaneously

• Antibody concentration:

  • Recommended concentration is 0.25 μg per 10^6 cells in a 100 μl suspension

  • Titrate to determine optimal concentration for your specific cell type

• Controls for flow cytometry:

  • Isotype controls to assess non-specific binding

  • FMO (Fluorescence Minus One) controls for accurate gating

  • Cell cycle synchronized populations as biological controls

• Multiparameter considerations:

  • CCNE2 analysis can be combined with DNA content staining (PI or DAPI)

  • Consider antibody-fluorophore combinations to minimize spectral overlap

  • Include single-stained controls for compensation

• Analysis strategies:

  • Gate on cell cycle phases based on DNA content

  • Analyze CCNE2 expression levels relative to cell cycle position

  • Consider analyzing median fluorescence intensity rather than percent positive

For cell cycle studies, combining CCNE2 staining with EdU incorporation can provide more precise S-phase identification than traditional DNA content analysis alone.

What are common pitfalls when working with CCNE2 antibodies and how can they be addressed?

Researchers frequently encounter several challenges when working with CCNE2 antibodies:

• Weak or absent signal in Western blot:

  • Ensure target expression: CCNE2 levels vary throughout the cell cycle; synchronize cells at G1/S transition

  • Increase antibody concentration: Try 1:500 dilution if 1:1000 yields weak signal

  • Extend primary antibody incubation: Consider overnight at 4°C instead of shorter incubations

  • Verify transfer efficiency: Use reversible staining or ladder visualization

  • Check extraction method: CCNE2 may require specific lysis conditions to release nuclear proteins

• High background in immunostaining:

  • Optimize blocking: Try different blocking agents (BSA, normal serum, commercial blockers)

  • Reduce antibody concentration: Test more dilute solutions (1:800 instead of 1:200)

  • Increase washing duration and frequency

  • Evaluate autofluorescence: Consider quenching steps if using tissues with high autofluorescence

• Unexpected molecular weight:

  • Verify protein loading: Confirm with housekeeping proteins

  • Consider post-translational modifications: CCNE2 undergoes phosphorylation at multiple sites (Thr62, Ser88, Ser72, Thr380, Ser384)

  • Check for degradation: Use protease inhibitor cocktails during lysis

  • Validate with positive control: Jurkat cells express detectable CCNE2 levels

• Cross-reactivity issues:

  • Validate species reactivity: Confirm the antibody is validated for your species of interest

  • Test antibodies from multiple vendors: Different clones may have different specificity profiles

  • Perform knockout/knockdown validation if possible

Implementing these troubleshooting strategies can help resolve common issues with CCNE2 detection.

How does CCNE2 expression vary across cell types and how might this affect experimental design?

CCNE2 expression exhibits significant variation across cell types and physiological states:

• Cell type-specific expression patterns:

  • High expression in proliferating cells and certain cancer types

  • Low or undetectable in quiescent or terminally differentiated cells

  • Particularly high expression in testicular tissue and certain breast cancer subtypes

• Cell cycle-dependent expression:

  • CCNE2 exhibits periodic expression peaking at the G1/S transition

  • Expression is minimal in G0 and early G1 phases

  • Levels decrease rapidly during S phase progression

• Implications for experimental design:

  • Sample selection: Choose positive control tissues/cells known to express CCNE2 (e.g., Jurkat cells, breast cancer tissues, testicular tissue)

  • Timing of analysis: Synchronize cells or sort by cell cycle phase for consistent results

  • Detection methods: For tissues/cells with low expression, use more sensitive detection methods (e.g., amplification systems for IHC, sensitive ECL for Western blot)

  • Quantification approaches: Consider normalization to cell cycle markers when comparing CCNE2 levels between samples

• Cancer-specific considerations:

  • CCNE2 is frequently dysregulated in cancer, with overexpression in many tumor types

  • Some cancers may express unique isoforms or post-translationally modified variants

  • Consider analyzing matched normal-tumor pairs to assess disease-specific alterations

Understanding these expression patterns is essential for proper experimental design and accurate interpretation of CCNE2 detection results.

What are the key differences between various commercial CCNE2 antibodies and how should I select one for my research?

Commercial CCNE2 antibodies vary in several important characteristics that can impact experimental outcomes:

• Host species and antibody type:

  • Most common format: Rabbit polyclonal antibodies

  • Polyclonal advantages: Recognition of multiple epitopes, potentially higher sensitivity

  • Polyclonal disadvantages: Batch-to-batch variation, potential for higher background

• Immunogen strategies:

  • Recombinant protein immunogens: Common approach that may yield antibodies recognizing native protein

  • Synthetic peptide immunogens: May be more specific to particular domains or isoforms

  • Verify immunogen sequence location if studying specific CCNE2 domains or modified forms

• Validated applications across manufacturers:

• Selection criteria for specific applications:

  • For Western blotting: Select antibodies specifically validated by the manufacturer for WB with clear single-band detection at ~48 kDa

  • For IHC/IF: Choose antibodies with demonstrated nuclear localization pattern and validated antigen retrieval protocols

  • For co-IP studies: Verify the antibody doesn't interact with the CCNE2-CDK2 binding interface if studying complexes

  • For quantitative applications: Consider monoclonal antibodies for greater consistency in quantitative studies

• Validation documentation:

  • Review provided validation images (Western blot bands, IHC/IF patterns)

  • Check for validation in knockout/knockdown systems

  • Consider published literature using specific antibody catalog numbers

When selecting an antibody, prioritize those with validation in your specific application and experimental system, even if this means compromising on price or convenience factors.

How can CCNE2 antibodies be utilized in cancer research to investigate cell cycle dysregulation?

CCNE2 antibodies have become valuable tools in cancer research due to the frequent dysregulation of CCNE2 in various malignancies:

• Prognostic biomarker studies:

  • CCNE2 overexpression correlates with poor prognosis in several cancer types

  • IHC protocols using dilutions between 1:400-1:1600 can be used to assess CCNE2 expression in tumor tissue microarrays

  • Scoring systems that account for both intensity and percentage of positive cells provide quantitative data for correlation with clinical outcomes

• Cell cycle checkpoint analysis:

  • Combined staining of CCNE2 with CDK inhibitors (p21, p27) can reveal disruption of cell cycle checkpoints

  • Flow cytometry protocols (using 0.25 μg antibody per 10^6 cells) enable single-cell correlation of CCNE2 levels with DNA content

  • Phospho-specific antibodies targeting CCNE2 modification sites (Thr62, Ser88, Ser72, Thr380, Ser384) can provide insight into post-translational regulation

• Therapeutic response assessment:

  • Monitoring CCNE2 levels before and after treatment with CDK inhibitors or other targeted therapies

  • Western blotting (1:1000-1:2000 dilution) can quantify changes in protein expression following treatment

  • IF/ICC approaches (1:200-1:800 dilution) enable visualization of subcellular localization changes in response to therapy

• Mechanistic studies:

  • Immunoprecipitation protocols (using 0.5-4.0 μg antibody for 1.0-3.0 mg protein) can identify novel CCNE2 binding partners in cancer cells

  • ChIP (Chromatin Immunoprecipitation) adaptations can investigate CCNE2's role in regulating gene expression

  • Co-staining CCNE2 with DNA damage markers can reveal connections between CCNE2 overexpression and genomic instability

These applications demonstrate how CCNE2 antibodies can provide insights into cancer pathogenesis and potential therapeutic vulnerabilities.

What approaches can be used to study post-translational modifications of CCNE2?

Studying post-translational modifications (PTMs) of CCNE2 requires specialized approaches:

• Phospho-specific detection strategies:

  • CCNE2 undergoes phosphorylation at multiple sites including Thr62, Ser88, Ser72, Thr380, and Ser384

  • These modifications are regulated by kinases including CDK2 and GSK-3

  • Approaches include:

    • Phospho-specific antibodies (when available)

    • Phosphatase treatment comparisons

    • Mobility shift analysis on Phos-tag gels

    • Mass spectrometry for comprehensive PTM mapping

• Ubiquitination analysis:

  • CCNE2 is regulated by ubiquitin-mediated proteolysis

  • Strategies include:

    • Proteasome inhibitor treatment (MG132) to accumulate ubiquitinated forms

    • Immunoprecipitation under denaturing conditions followed by ubiquitin detection

    • Expression of tagged ubiquitin constructs to track modification

• SUMOylation and other modifications:

  • Less well-characterized but potentially important for CCNE2 regulation

  • Specialized IP protocols with SUMO-specific antibodies

  • SUMO-site prediction tools to guide mutational analysis

• Methodology considerations:

  • Sample preparation must preserve modifications (phosphatase/protease inhibitors)

  • Lysis buffers should be optimized for the specific modification under study

  • Controls should include modification-inducing treatments (e.g., cell cycle synchronization)

  • Two-dimensional gel electrophoresis can separate modified isoforms

• Functional correlation approaches:

  • Site-directed mutagenesis of modification sites to create non-modifiable variants

  • Correlation of modification status with protein stability, localization, and activity

  • Inhibitor studies targeting specific modifying enzymes (kinases, E3 ligases)

These approaches enable detailed characterization of CCNE2 regulation by post-translational modifications, providing insight into cell cycle control mechanisms.

How can CCNE2 antibodies be integrated into high-throughput or automated research platforms?

Integration of CCNE2 antibodies into high-throughput and automated platforms requires specific optimization:

• Automated Western blotting systems:

  • Validated CCNE2 antibody dilutions for automated systems: 1:1000-1:2000

  • Recommended positive controls: Jurkat cell lysates

  • Protein loading: 10-30 μg total protein per lane

  • Detection systems: Compatible with both chemiluminescence and fluorescent secondary antibodies

  • Quality control metrics: CV% should be established in validation runs

• High-content imaging for CCNE2:

  • Optimized antibody concentration: 1:200-1:800 dilution for IF/ICC applications

  • Nuclear segmentation: DAPI counterstain allows accurate nuclear identification

  • Multiparametric analysis possibilities:

    • CCNE2 intensity (nuclear)

    • Cell cycle phase (via DNA content)

    • Proliferation markers (Ki-67, EdU incorporation)

    • Additional pathway components (CDK2, p21, etc.)

• Tissue microarray analysis:

  • IHC protocol optimization: 1:400-1:1600 dilution with appropriate antigen retrieval

  • Automated scoring algorithms:

    • Nuclear intensity measurement

    • Percent positive cells

    • H-score calculation (combining intensity and percentage)

  • Required controls: Normal tissues with expected low expression

• Flow cytometry automation:

  • Standard concentration: 0.25 μg per 10^6 cells

  • Plate-based high-throughput flow cytometry considerations:

    • Fixation/permeabilization must be uniform across wells

    • Antibody concentration may need adjustment for automated systems

    • Include standardized beads for day-to-day calibration

• Proteomic approaches:

  • IP-MS workflows: 0.5-4.0 μg antibody per mg of lysate

  • Reverse-phase protein array (RPPA) compatibility

  • Multiplexed antibody-based methods (Luminex, Meso Scale Discovery)

Proper validation with appropriate controls is essential when transitioning from manual to automated methods, with particular attention to batch effects and system-specific optimizations.

What are the latest methodological advances in studying CCNE2 protein-protein interactions?

Recent methodological advances have expanded our ability to study CCNE2 protein interactions:

• Proximity-based interaction techniques:

  • BioID/TurboID: Fusion of biotin ligase to CCNE2 allows identification of proximal proteins

  • APEX2 proximity labeling: Provides temporal resolution of CCNE2 interactome changes

  • FRET/BRET approaches: Real-time monitoring of CCNE2-CDK2 interactions in living cells

  • These methods overcome limitations of traditional co-IP approaches, which may miss transient or weak interactions

• Advanced co-immunoprecipitation strategies:

  • Optimized antibody amounts: 0.5-4.0 μg for 1.0-3.0 mg of total protein lysate

  • Crosslinking IP: Preserves transient interactions through chemical crosslinking

  • Sequential IP: Isolates specific complexes containing multiple proteins

  • IP-mass spectrometry: Comprehensive identification of CCNE2 binding partners

  • RIME (Rapid Immunoprecipitation Mass spectrometry of Endogenous proteins): Specialized for chromatin-associated complexes

• Single-molecule techniques:

  • Single-molecule pull-down: Analyzes stoichiometry of CCNE2-containing complexes

  • Single-molecule FRET: Provides structural insights into CCNE2-partner interactions

  • Super-resolution microscopy: Visualizes CCNE2 complexes beyond the diffraction limit

• Live-cell interaction monitoring:

  • Split fluorescent/luminescent protein complementation

  • Optogenetic approaches to control CCNE2 interactions

  • FRAP (Fluorescence Recovery After Photobleaching): Measures interaction dynamics

• Computational approaches:

  • Molecular docking simulations

  • Network analysis of CCNE2 interactome

  • Machine learning prediction of interaction sites

These advanced methodologies provide unprecedented insights into the dynamic protein-protein interactions of CCNE2 throughout the cell cycle and in disease states, moving beyond traditional co-immunoprecipitation approaches.

What emerging techniques are likely to enhance CCNE2 antibody applications in future research?

Several emerging technologies are poised to transform CCNE2 antibody applications:

• Single-cell proteomics:

  • Integration of CCNE2 antibodies into mass cytometry (CyTOF) panels

  • Single-cell Western blotting technologies for heterogeneity analysis

  • Spatial proteomics approaches (e.g., Imaging Mass Cytometry, CODEX)

  • These approaches will reveal cell-to-cell variation in CCNE2 expression and modification

• Nanobody and recombinant antibody technologies:

  • Development of CCNE2-specific nanobodies with enhanced penetration for live-cell imaging

  • Site-specific conjugation strategies for precise reporter attachment

  • Bispecific antibodies targeting CCNE2 and interacting partners simultaneously

  • These formats may offer improved specificity and reduced background

• Advanced imaging modalities:

  • Super-resolution microscopy optimized for CCNE2 visualization

  • Expansion microscopy protocols compatible with CCNE2 antibodies

  • Light-sheet microscopy for 3D visualization of CCNE2 in tissues and organoids

  • These approaches will reveal subcellular details previously inaccessible

• Functional antibody applications:

  • Conformation-specific antibodies that distinguish active/inactive CCNE2

  • Intrabodies that track and potentially modulate CCNE2 function in living cells

  • Degradation-inducing antibody conjugates for targeted CCNE2 proteolysis

  • These tools will move beyond detection to functional perturbation

• AI-enhanced antibody validation and optimization:

  • Machine learning algorithms to predict optimal antibody conditions

  • Automated image analysis for unbiased quantification

  • Integration of antibody-based data with multi-omics datasets

  • These computational approaches will maximize information extraction from antibody-based experiments

These emerging techniques will expand the utility of CCNE2 antibodies beyond traditional applications, providing deeper insights into cell cycle regulation in normal and disease states.

How are CCNE2 antibodies contributing to our understanding of cancer and potential therapeutic approaches?

CCNE2 antibodies are making significant contributions to cancer research and therapeutic development:

• Prognostic and predictive biomarker development:

  • IHC protocols using CCNE2 antibodies (1:400-1:1600 dilution) enable patient stratification

  • CCNE2 overexpression correlates with aggressive disease in multiple cancer types

  • Combined detection of CCNE2 with other markers provides superior prognostic information

  • These applications help identify patients who might benefit from specific targeted therapies

• Therapeutic target validation:

  • Western blotting (1:1000-1:2000 dilution) quantifies CCNE2 levels following treatment

  • Flow cytometry (0.25 μg per 10^6 cells) assesses changes in CCNE2-positive cell populations

  • IF/ICC approaches (1:200-1:800) visualize subcellular redistribution in response to therapy

  • These methods help validate CCNE2 as a direct or indirect drug target

• Mechanism of action studies:

  • IP protocols (0.5-4.0 μg antibody) identify altered protein interactions following treatment

  • Phospho-specific detection reveals changes in CCNE2 regulation in response to therapy

  • Multiplexed detection correlates CCNE2 with downstream pathway components

  • These insights clarify how existing and experimental drugs affect the CCNE2 pathway

• Resistance mechanism investigation:

  • Antibody-based detection reveals CCNE2 alterations in drug-resistant cells

  • Correlation of CCNE2 levels/modifications with treatment response

  • Identification of compensatory pathways when CCNE2 is targeted

  • These findings suggest combination strategies to overcome resistance

• Emerging therapeutic approaches:

  • Antibody-drug conjugates targeting CCNE2-overexpressing cells

  • Proteolysis-targeting chimeras (PROTACs) for CCNE2 degradation

  • Synthetic lethal approaches exploiting CCNE2 overexpression

  • Immunotherapy strategies targeting CCNE2-derived peptides

CCNE2 antibodies thus serve as critical tools in both understanding cancer biology and developing the next generation of targeted therapies, particularly for cancers dependent on cell cycle dysregulation.