jmj3 Antibody

What is JMJD3/KDM6B and why is it significant in epigenetic research?

JMJD3/KDM6B is a histone demethylase that specifically demethylates trimethylated and dimethylated 'Lys-27' of histone H3 (H3K27me3/me2), playing a central role in the histone code regulation. Its significance stems from its involvement in key biological processes including:

• Regulation of posterior development through HOX gene expression modulation

• Participation in inflammatory responses via macrophage differentiation

• Activation of the INK4A-ARF tumor suppressor locus in response to stress stimuli

• Epigenetic regulation during cellular senescence

The protein has a molecular weight of approximately 177 kDa and functions primarily by removing repressive H3K27me3 marks, thereby enabling gene activation .

How should I select between monoclonal and polyclonal JMJD3 antibodies for specific experimental applications?

Selection should be based on your experimental objectives:

Monoclonal Antibodies (e.g., Clone 67-A2):

• Optimal for applications requiring high specificity and reproducibility

• Suitable for detecting specific epitopes (e.g., amino acids 1028-1684 of human JMJD3)

• Preferable for longitudinal studies where batch consistency is crucial

• Generally produce cleaner results in Western blot applications at 0.5-2 μg/ml dilution

Polyclonal Antibodies (e.g., DF13101):

• Better for applications requiring higher sensitivity

• Recognize multiple epitopes, increasing detection probability in partially denatured samples

• Useful when analyzing samples across species (e.g., human and mouse reactivity)

• Advantageous for detecting proteins expressed at low levels

Consider cross-species reactivity requirements—certain antibodies demonstrate verified reactivity with human and mouse JMJD3, with predicted reactivity to bovine, horse, sheep, rabbit, and dog proteins .

What are the validated applications for JMJD3 antibodies in epigenetic research?

When citing experimental results using these antibodies, proper format should be used (e.g., "Affinity Biosciences Cat# DF13101, RRID:AB_2846061") .

What are the optimal protocols for using JMJD3 antibodies in Western blot analysis?

For optimal Western blot results with JMJD3 antibodies, implement the following protocol:

• Sample Preparation:

  • Use RIPA or NP-40 based lysis buffers containing protease inhibitors

  • Include phosphatase inhibitors if phosphorylation status is relevant

  • Denature samples at 95°C for 5 minutes in Laemmli buffer with DTT or β-mercaptoethanol

• Gel Electrophoresis:

  • Use gradient gels (4-12% or 4-15%) to effectively resolve the 177 kDa JMJD3 protein

  • Load 20-50 μg of total protein per lane

  • Include positive controls (cells known to express JMJD3) and negative controls

• Transfer and Blocking:

  • Perform wet transfer for large proteins (>100 kDa) for 2 hours or overnight at 4°C

  • Block with 5% non-fat milk or BSA in TBST for 1 hour at room temperature

• Antibody Incubation:

  • For monoclonal antibodies: Dilute to 0.5-2 μg/ml in blocking buffer

  • For polyclonal antibodies: Determine optimal dilution empirically

  • Incubate overnight at 4°C with gentle rocking

• Detection:

  • Use HRP-conjugated secondary antibodies specific to host species

  • Visualize using ECL or other chemiluminescent detection methods

  • Extended exposure times may be necessary for low abundance samples

How can I validate the specificity of JMJD3 antibodies in my experimental system?

Comprehensive validation requires multiple approaches:

• Knockdown/Knockout Validation:

  • Perform siRNA or shRNA-mediated knockdown of JMJD3

  • Compare protein levels between control and KD/KO samples by Western blot

  • Absence or reduction of the band in KD/KO samples confirms specificity

• Recombinant Protein Controls:

  • Test antibody against purified JMJD3 protein

  • Include related Jumonji-domain proteins (e.g., UTX/KDM6A) to assess cross-reactivity

• Multiple Antibody Comparison:

  • Use different antibodies targeting distinct epitopes of JMJD3

  • Concordant results increase confidence in specificity

• Expression System Validation:

  • Overexpress tagged JMJD3 constructs (wild-type or catalytically dead mutants)

  • Detect with both tag-specific and JMJD3 antibodies

  • Co-localization confirms antibody specificity

• Mass Spectrometry Validation:

  • Immunoprecipitate JMJD3 using the antibody

  • Confirm identity by mass spectrometry

What controls should I include when using JMJD3 antibodies in ChIP experiments?

For rigorous ChIP experiments with JMJD3 antibodies, include these essential controls:

• Input Control:

  • Reserve 5-10% of pre-immunoprecipitated chromatin

  • Use for normalization of ChIP-qPCR data

• Isotype Control:

  • Perform parallel IP with non-specific IgG from the same species

  • Establishes background enrichment levels

• Positive Genomic Controls:

  • Include primers for known JMJD3 targets (e.g., INK4A promoter region)

  • The INK4A locus shows enrichment during stress responses

• Negative Genomic Controls:

  • Include primers for regions not bound by JMJD3

  • Intergenic regions or housekeeping gene promoters are suitable

• Biological Context Controls:

  • Compare JMJD3 binding in relevant biological contexts:

    • Stress-induced vs. normal conditions

    • Before and after BRAF activation in senescence models

    • With and without stimuli that induce JMJD3 expression

• Complementary Histone Mark ChIP:

  • Perform parallel ChIP for H3K27me3

  • An inverse correlation between JMJD3 binding and H3K27me3 levels supports functional activity

How can JMJD3 antibodies be used to study the dynamics of H3K27 demethylation in cellular senescence models?

JMJD3 antibodies can reveal critical insights into senescence mechanisms through multi-faceted approaches:

• Temporal Profiling of JMJD3 Induction:

  • Perform time-course Western blots after senescence induction

  • JMJD3 protein levels increase as early as 6 hours after BRAF activation

  • This precedes p16 INK4A upregulation (24-48 hours), suggesting a causal relationship

  • Compare with UTX levels, which remain unchanged during this process

• ChIP-Seq Analysis:

  • Perform ChIP-seq with JMJD3 antibodies at multiple time points during senescence

  • Map genome-wide JMJD3 recruitment patterns

  • Correlate with:

    • H3K27me3 removal dynamics

    • Recruitment of RNA Polymerase II

    • Expression of senescence markers

• Co-Immunoprecipitation Studies:

  • Use JMJD3 antibodies to identify interaction partners during senescence

  • Analyze temporal changes in protein complexes

  • Include catalytically inactive JMJD3 mutants as controls

• Sequential ChIP (Re-ChIP):

  • Perform first ChIP with JMJD3 antibody

  • Re-ChIP with antibodies against other factors (e.g., CBX8 or other Polycomb group proteins)

  • This reveals co-occupancy and potential mechanism of Polycomb displacement

• Functional Validation Experiments:

  • Combine JMJD3 ChIP with gain/loss-of-function approaches

  • Compare binding profiles between:

    • Wild-type JMJD3 vs. catalytically inactive mutant

    • Control cells vs. JMJD3 knockdown/knockout cells

What methodological approaches can be used to investigate JMJD3 recruitment to specific gene loci?

To study JMJD3 recruitment with high precision, implement these advanced methodologies:

• Targeted ChIP-qPCR Analysis:

  • Design primers spanning regulatory regions of interest (e.g., INK4A-ARF locus)

  • Perform high-resolution mapping with primers at 500bp intervals

  • JMJD3 shows enrichment just upstream of the transcription start site (TSS) of INK4A

• ChIP-Sequencing (ChIP-seq):

  • Perform genome-wide mapping of JMJD3 binding

  • Analyze using computational approaches to identify:

    • Binding motifs

    • Co-occurring transcription factors

    • Chromatin accessibility patterns

• CUT&RUN or CUT&Tag Approaches:

  • These techniques offer higher signal-to-noise ratio than traditional ChIP

  • Require fewer cells and less antibody

  • Particularly valuable for scarce primary samples

• Chromatin Conformation Capture Techniques:

  • Combine with JMJD3 ChIP to study long-range interactions

  • Reveals 3D chromatin architecture at target loci

• Live-Cell Imaging:

  • Express fluorescently-tagged JMJD3

  • Perform real-time tracking of recruitment to chromatin

  • Correlate with expression of target genes

• Parallel Factor Analysis:

  • Simultaneously analyze JMJD3, H3K27me3, and transcription factors

  • Create comprehensive maps of epigenetic state transitions

  • Example: During BRAF activation, JMJD3 binding increases at INK4A promoter while CBX8 and H3K27me3 levels decrease

How can I analyze the interplay between JMJD3 and transcription factors during gene activation?

To investigate the coordinated action of JMJD3 and transcription factors:

• Sequential ChIP (Re-ChIP) Analysis:

  • First ChIP with JMJD3 antibody

  • Second ChIP with antibodies against candidate transcription factors

  • Quantify co-occupancy at specific genomic loci

• Proximity Ligation Assay (PLA):

  • Detect protein-protein interactions in situ

  • Identify cells and nuclear locations where JMJD3 interacts with specific factors

• Co-Immunoprecipitation Studies:

  • Precipitate with JMJD3 antibody

  • Identify interacting transcription factors by Western blot

  • Validate interactions after various stimuli (e.g., BRAF activation)

• Reporter Assays with Mutational Analysis:

  • Create reporter constructs containing JMJD3-regulated promoters

  • Mutate transcription factor binding sites

  • Assess impact on JMJD3 recruitment and promoter activation

  • Example: The JMJD3 promoter contains multiple regulatory elements, including distinct transcription start sites used in different cellular contexts

• Temporal Analysis of Factor Recruitment:

  • Perform time-course ChIP experiments

  • Determine sequential recruitment of factors during gene activation

  • JMJD3 is typically recruited early in the activation process, preceding target gene expression

Why might I detect multiple bands when using JMJD3 antibodies in Western blot analysis?

Multiple bands in JMJD3 Western blots may occur due to several biological and technical factors:

• Post-translational Modifications:

  • JMJD3 undergoes various modifications affecting migration patterns

  • Phosphorylation can result in mobility shifts

  • Solution: Include phosphatase treatment controls

• Proteolytic Processing:

  • Partial degradation during sample preparation

  • Solution: Use freshly prepared samples and include protease inhibitor cocktails

• Alternative Splice Variants:

  • JMJD3 exists in multiple isoforms

  • Solution: Validate with RT-PCR for specific isoforms

• Cross-Reactivity:

  • Antibody might recognize related proteins (e.g., UTX/KDM6A)

  • Solution: Confirm specificity with knockdown experiments

  • Include recombinant JMJD3 protein as positive control

• Non-specific Binding:

  • Particularly common with polyclonal antibodies

  • Solution: Optimize blocking conditions and antibody dilutions

  • Try different blocking agents (milk vs. BSA)

• Experimental Validation Table:

How can I improve signal-to-noise ratio when using JMJD3 antibodies in ChIP experiments?

To optimize JMJD3 ChIP experiments:

• Crosslinking Optimization:

  • Test different formaldehyde concentrations (0.5-2%)

  • Try dual crosslinking (formaldehyde + protein-specific crosslinkers)

  • Optimize crosslinking time (5-20 minutes)

• Sonication Parameters:

  • Aim for chromatin fragments of 200-500bp

  • Verify fragmentation efficiency by agarose gel electrophoresis

  • Insufficient fragmentation reduces antibody accessibility

• Antibody Selection and Titration:

  • Compare different JMJD3 antibodies for ChIP efficiency

  • Titrate antibody amounts (2-10 μg per ChIP reaction)

  • Pre-clear chromatin with protein A/G beads to reduce background

• Washing Conditions:

  • Increase stringency of wash buffers (salt concentration, detergent)

  • Perform additional washing steps

  • Use LiCl wash to reduce non-specific DNA binding

• Technical Approaches:

  • Consider switching to CUT&RUN or CUT&Tag for improved signal-to-noise

  • Use ChIP-grade antibodies specifically validated for this application

  • Include spike-in normalization controls

• Data Analysis:

  • Use appropriate normalization (input, IgG, spike-in)

  • Apply statistical methods to distinguish signal from noise

  • Focus analysis on regions with consistent enrichment across replicates

  • When studying the INK4A locus, focus on the regions just upstream of the TSS where JMJD3 enrichment is highest

What approaches can I use to validate JMJD3 knockdown efficiency at both RNA and protein levels?

For comprehensive validation of JMJD3 knockdown:

• mRNA Level Validation:

  • Quantitative RT-PCR with primers targeting different exons

  • Include primers that span exon-exon junctions

  • Normalize to multiple reference genes

  • Aim for >70% reduction in transcript levels

• Protein Level Validation:

  • Western blot with JMJD3 antibodies

  • Use gradient gels for optimal resolution of the 177 kDa protein

  • Include loading controls (β-actin, GAPDH, or total histone H3)

  • Perform densitometry analysis for quantification

• Functional Validation:

  • ChIP-qPCR for H3K27me3 at known JMJD3 target genes

  • Expect increased H3K27me3 levels at targets following knockdown

  • Measure expression of downstream targets (e.g., INK4A/p16)

• Time-Course Analysis:

  • Monitor knockdown efficiency at multiple time points

  • Protein depletion typically lags behind mRNA reduction

  • For studying senescence, monitor over 5-6 passages to observe effects on cellular aging

• Single-Cell Analysis:

  • Immunofluorescence to assess knockdown efficiency at single-cell level

  • Identify potential escapees that maintain JMJD3 expression

• Validation Checklist:

  • Confirm specificity with rescue experiments using knockdown-resistant constructs

  • Use multiple independent siRNA/shRNA sequences

  • Include scrambled/non-targeting control

  • In OIS models, verify the impact on senescence markers and proliferation

How can JMJD3 antibodies be utilized in cancer research to understand epigenetic dysregulation?

JMJD3 antibodies provide valuable tools for investigating cancer-associated epigenetic mechanisms:

• Tumor Suppressor Regulation:

  • Study JMJD3's role in activating the INK4A-ARF locus

  • Compare JMJD3 binding and H3K27me3 levels at tumor suppressor loci across normal vs. cancer cells

  • Investigate the bypass of senescence in cancer cells despite JMJD3 upregulation

• Stress Response Mechanisms:

  • Analyze JMJD3 induction following various oncogenic stresses

  • JMJD3 increases within 2-4 hours after BRAF activation

  • UV irradiation similarly induces JMJD3 upregulation

  • Correlate with changes in global H3K27me3 landscapes

• Therapeutic Target Exploration:

  • Use ChIP-seq with JMJD3 antibodies to identify cancer-specific target genes

  • Investigate effects of JMJD3 inhibitors on chromatin states

  • Perform immunoprecipitation mass spectrometry to identify cancer-specific interaction partners

• Prognostic Biomarker Development:

  • Analyze JMJD3 expression and localization in tumor samples

  • Correlate with clinical outcomes and response to therapy

  • Develop tissue microarray approaches with optimized IHC protocols

• Senescence Bypass Mechanisms:

  • Compare JMJD3 recruitment in senescence-sensitive vs. resistant cells

  • Investigate post-translational modifications that alter JMJD3 activity

  • Study JMJD3 promoter regulation in cancer contexts

What are the methodological considerations for studying JMJD3 in embryonic development and stem cell models?

For developmental biology applications:

• Temporal Expression Analysis:

  • Track JMJD3 expression during differentiation processes

  • The embryonic stem cell-specific transcription start site (ESC-TSS) differs from the macrophage-specific start site (MF-TSS)

  • Use antibodies that recognize conserved epitopes across developmental stages

• ChIP-Seq in Limited Cell Populations:

  • Adapt protocols for low cell numbers

  • Consider CUT&Tag methods for improved sensitivity

  • Focus on HOX gene clusters, known targets of JMJD3 regulation

• Lineage-Specific Analysis:

  • Compare JMJD3 binding patterns across different lineage commitments

  • Correlate with changes in H3K27me3 distributions

  • Analyze co-occupancy with lineage-specific transcription factors

• Functional Validation in Development:

  • Combine with precise temporal knockdown/knockout systems

  • Use catalytically inactive mutants to distinguish enzymatic from structural roles

  • Monitor effects on posterior development and HOX gene expression

• Single-Cell Applications:

  • Adapt immunofluorescence protocols for detecting native JMJD3

  • Combine with lineage markers to identify stage-specific expression

  • Correlate with single-cell transcriptomics data

• Organism-Specific Considerations:

  • Verify antibody cross-reactivity with model organism homologs

  • Optimize fixation conditions for embryonic tissues

  • Consider epitope accessibility in different developmental contexts

How can JMJD3 antibodies help elucidate the role of epigenetic regulation in inflammatory responses?

JMJD3 antibodies provide critical insights into inflammation-associated epigenetic mechanisms:

• Macrophage Differentiation and Activation:

  • Track JMJD3 recruitment during macrophage polarization

  • Analyze binding at inflammation-responsive genes

  • Compare with other epigenetic modifiers during inflammatory activation

• Stimulus-Specific Responses:

  • Compare JMJD3 induction across different inflammatory triggers

  • Analyze promoter usage (e.g., macrophage-specific TSS vs. ESC-TSS)

  • Correlate with cytokine production and inflammatory gene expression

• Temporal Dynamics Analysis:

  • Perform time-course ChIP-seq after inflammatory stimulation

  • Map the kinetics of H3K27me3 removal at target genes

  • Correlate with recruitment of inflammatory transcription factors

• Tissue-Specific Inflammatory Responses:

  • Optimize immunohistochemistry protocols for tissue samples

  • Compare JMJD3 expression and localization across inflamed vs. normal tissues

  • Correlate with disease severity markers

• Therapeutic Modulation:

  • Use JMJD3 antibodies to evaluate effects of anti-inflammatory compounds

  • Monitor changes in JMJD3 recruitment and H3K27me3 levels

  • Develop high-throughput screening assays based on JMJD3 activity

• Cross-Talk with Other Inflammatory Pathways:

  • Investigate interactions between JMJD3 and NF-κB signaling

  • Study how stress responses integrate with inflammatory activation

  • Analyze post-translational modifications of JMJD3 during inflammation