Acetyl-CREBBP (K1535) Antibody

What is Acetyl-CREBBP (K1535) Antibody and its significance in epigenetic research?

Acetyl-CREBBP (K1535) Antibody is a research-grade antibody specifically designed to detect CREBBP protein when acetylated at lysine 1535. This antibody serves as a crucial tool for investigating post-translational modifications of CREBBP, which functions as both a histone acetyltransferase and a transcriptional coactivator.

The significance of this antibody lies in its ability to monitor the acetylation status of CREBBP, which directly impacts its function as a transcriptional regulator. CREBBP acetylates histones (particularly histone 3 lysine 18) and mediates cAMP-gene regulation by binding to phosphorylated CREB1 . Understanding CREBBP acetylation patterns is essential for elucidating its role in various cellular processes, including gene expression regulation, cell cycle control, and DNA damage response.

For optimal results when using this antibody, researchers should consider the following methodological approaches:

• Validate antibody specificity using CREBBP knockout or knockdown controls

• Compare acetylation patterns across different cell types and conditions

• Incorporate phosphorylation status analysis, as phosphorylation may influence acetylation events

What experimental techniques can effectively utilize Acetyl-CREBBP (K1535) Antibody?

Acetyl-CREBBP (K1535) Antibody can be employed across multiple experimental platforms:

Immunoblotting/Western Blot Analysis:

• Recommended dilution: 1:500-1:2000 in 5% BSA

• Sample preparation: Nuclear extracts yield better results than whole cell lysates

• Controls: Include acetylation-inducing conditions (HDAC inhibitors) as positive controls

Immunoprecipitation:

• Can be used to isolate acetylated CREBBP and its associated protein complexes

• Helps identify protein-protein interactions influenced by K1535 acetylation status

Immunofluorescence:

• Useful for determining subcellular localization of acetylated CREBBP

• Particularly valuable for assessing nuclear vs. cytoplasmic distribution

Chromatin Immunoprecipitation (ChIP):

• Essential for mapping acetylated CREBBP binding sites genome-wide

• Can be coupled with sequencing (ChIP-seq) to generate comprehensive binding profiles

CREBBP's role as a histone acetyltransferase makes it a key player in epigenetic regulation. This antibody allows researchers to distinguish when CREBBP itself is acetylated, potentially altering its function in acetylating other proteins including histones and KRAS .

How can researchers troubleshoot common issues with Acetyl-CREBBP (K1535) Antibody experiments?

When working with Acetyl-CREBBP (K1535) Antibody, researchers frequently encounter several challenges that can be addressed through methodical troubleshooting:

Weak or No Signal:

• Increase antibody concentration incrementally

• Extend primary antibody incubation (overnight at 4°C)

• Use enhanced detection systems with higher sensitivity

• Ensure CREBBP is not degraded during sample preparation by adding protease inhibitors

High Background:

• Increase blocking time and concentration (5% BSA recommended over milk-based blockers)

• Add 0.1% Tween-20 to washing buffers

• Pre-absorb antibody with cell lysate from CREBBP knockout cells

• Reduce secondary antibody concentration

Non-specific Bands:

• Include specific peptide competition controls

• Run parallel samples with unmodified CREBBP antibody for comparison

• Increase wash stringency and duration

• Consider using monoclonal alternatives if available

Proper sample preparation is critical - acetylation marks can be lost during processing. Always include HDAC inhibitors (e.g., trichostatin A, sodium butyrate) in lysis buffers to preserve acetylation status.

How can Acetyl-CREBBP (K1535) Antibody be utilized to investigate CREBBP's role in hematological malignancies?

Acetyl-CREBBP (K1535) Antibody provides a powerful tool for investigating CREBBP's involvement in hematological malignancies, particularly childhood acute lymphoblastic leukemia (ALL) and diffuse large B-cell lymphoma (DLBCL).

Recent studies have shown that heterozygous inactivating mutations in CREBBP are particularly frequent in relapsed childhood ALL and are associated with hyperdiploid karyotype and KRAS mutations . CREBBP mutations are also common in follicular lymphoma and DLBCL . The acetylation status of CREBBP at K1535 may influence its activity and interaction with other proteins in these disease contexts.

Methodological approaches for studying CREBBP acetylation in hematological malignancies include:

• Comparative analysis of acetylation patterns: Compare Acetyl-CREBBP (K1535) levels between patient-derived samples and healthy controls using immunoblotting or immunohistochemistry.

• Functional correlation studies: Correlate acetylation status with CREBBP's ability to acetylate downstream targets like histone H3K18 and KRAS.

• Mutation impact assessment: Investigate how common CREBBP mutations affect K1535 acetylation using site-directed mutagenesis and the Acetyl-CREBBP (K1535) Antibody.

• Therapeutic response prediction: Monitor changes in CREBBP K1535 acetylation during treatment with HDAC inhibitors or MEK inhibitors to identify potential biomarkers of response.

Studies have demonstrated that CREBBP directly acetylates KRAS and that CREBBP knockdown enhances signaling of the RAS/RAF/MEK/ERK pathway in Ras pathway-mutated ALL cells . This suggests that loss of CREBBP function may potentiate oncogenic RAS signaling in leukemia, making it a potential therapeutic target.

What approaches can validate the specificity of Acetyl-CREBBP (K1535) Antibody in complex experimental systems?

Ensuring antibody specificity is paramount for generating reliable scientific data. For Acetyl-CREBBP (K1535) Antibody, multiple complementary validation strategies should be employed:

Genetic Validation:

• CRISPR/Cas9-mediated CREBBP knockout serves as a negative control

• Site-directed mutagenesis of K1535 to arginine (K1535R) to create a non-acetylatable version

• Overexpression of wild-type vs. K1535R mutant CREBBP followed by immunoblotting

Biochemical Validation:

• Peptide competition assays using acetylated vs. non-acetylated K1535 peptides

• Pre-absorption tests with acetylated vs. non-acetylated recombinant CREBBP

• Mass spectrometry confirmation of K1535 acetylation in immunoprecipitated samples

Functional Validation:

• Treating cells with HDAC inhibitors should increase K1535 acetylation signal

• Histone deacetylase 3 (HDAC3) inhibition specifically may affect CREBBP acetylation status, as HDAC3 has been implicated in regulating CREBBP-mediated functions

• Protein-observed fluorine NMR (PrOF NMR) can be used to confirm structural changes associated with acetylation

Cross-Reactivity Assessment:

• Test antibody against EP300 (p300), which has high homology to CREBBP

• Examine reactivity in tissues from different species to determine conservation of the epitope

These validation approaches ensure that the observed signals truly represent acetylated CREBBP at K1535 rather than non-specific interactions or cross-reactivity with similar proteins like EP300.

How can Acetyl-CREBBP (K1535) Antibody be integrated into studies of the RAS/RAF/MEK/ERK signaling pathway?

The interplay between CREBBP acetylation and RAS pathway signaling represents a promising area of investigation where Acetyl-CREBBP (K1535) Antibody can provide valuable insights:

Experimental Design Considerations:

• Temporal analysis of acetylation dynamics:

  • Monitor K1535 acetylation status after activating or inhibiting the RAS pathway

  • Use time-course experiments to determine whether acetylation precedes or follows RAS activation

• Dual immunoprecipitation approach:

  • First immunoprecipitate with Acetyl-CREBBP (K1535) Antibody

  • Then probe for RAS pathway components or vice versa

  • This reveals which fraction of CREBBP interacts with RAS pathway proteins

• Inhibitor studies:

  • Compare K1535 acetylation patterns following treatment with:

    • MEK inhibitors

    • HDAC inhibitors

    • Bromodomain inhibitors specific to CREBBP

Research has shown that CREBBP directly acetylates KRAS and that CREBBP knockdown enhances signaling of the RAS/RAF/MEK/ERK pathway in Ras pathway-mutated ALL cells . This suggests a complex regulatory relationship where:

• CREBBP acetylation status may influence its ability to acetylate KRAS

• KRAS acetylation may modulate its signaling capacity

• Changes in CREBBP function (via mutation or altered acetylation) may enhance oncogenic RAS signaling

This creates a potential feedback loop where measuring acetylation at K1535 could serve as a biomarker for predicting RAS pathway activity in cancer cells.

What controls should be included when using Acetyl-CREBBP (K1535) Antibody in ChIP-seq experiments?

ChIP-seq with Acetyl-CREBBP (K1535) Antibody requires rigorous controls to ensure data validity:

Essential Controls:

• Input control: Unimmunoprecipitated chromatin sample that represents the starting material

• IgG control: Non-specific antibody of the same isotype to establish background signal levels

• Total CREBBP ChIP: Parallel ChIP with antibody recognizing total CREBBP (acetylated and non-acetylated) to normalize acetylation-specific signals

• Acetylation modulation controls:

  • Samples treated with HDAC inhibitors (expected to increase acetylation)

  • Samples with CREBBP knockdown/knockout (negative control)

  • Samples expressing K1535R mutant (non-acetylatable control)

• Spike-in normalization: Addition of chromatin from a different species (e.g., Drosophila) with a species-specific antibody to normalize technical variation

Data Analysis Considerations:

When analyzing ChIP-seq data for acetylated CREBBP, researchers should look for:

• Enrichment at enhancer regions, particularly those associated with immune response genes and B-cell signaling

• Co-localization with histone H3K27 acetylation marks

• Overlap with BCL6/SMRT/HDAC3 complex binding sites in lymphoma studies

• Association with cAMP-responsive elements given CREBBP's role in cAMP-gene regulation

CREBBP loss-of-function has been shown to result in focal depletion of enhancer H3K27 acetylation and aberrant transcriptional silencing of genes that regulate B-cell signaling and immune responses . ChIP-seq with Acetyl-CREBBP (K1535) Antibody can help determine whether K1535 acetylation status correlates with these effects.

How can Acetyl-CREBBP (K1535) Antibody help distinguish between CREBBP and EP300 functions?

CREBBP and EP300 (also known as p300) are paralogous histone acetyltransferases with overlapping but distinct functions. Acetyl-CREBBP (K1535) Antibody can help delineate their specific roles through several methodological approaches:

Comparative Analysis Strategies:

• Sequential ChIP (re-ChIP):

  • First ChIP with Acetyl-CREBBP (K1535) Antibody

  • Second ChIP with EP300-specific antibody (or vice versa)

  • This identifies genomic loci where both modified proteins co-localize

• Selective inhibition studies:

  • Use selective inhibitors of CREBBP and EP300 bromodomains (e.g., compound 2, which shows high selectivity for CREBBP/EP300 over other bromodomains)

  • Monitor changes in K1535 acetylation

  • Compare effects on downstream target gene expression

• Knockdown/knockout comparison:

  • Perform parallel CREBBP and EP300 knockdown/knockout experiments

  • Use Acetyl-CREBBP (K1535) Antibody to assess changes in CREBBP acetylation

  • Compare effects on histone acetylation patterns, particularly H3K18 and H3K27

Research Applications:

The selective inhibition of CREBBP/EP300 bromodomains has shown promise in preclinical studies. Compound 2, which has Kd values of 200 and 240 nM for the CREBBP and EP300 bromodomains respectively, demonstrates significant selectivity over other bromodomains . Using Acetyl-CREBBP (K1535) Antibody in conjunction with such inhibitors can help determine:

• Whether bromodomain inhibition affects CREBBP's own acetylation status

• If acetylation at K1535 influences CREBBP's bromodomain function

• How CREBBP and EP300 differ in their regulation by acetylation

This information is particularly relevant for developing targeted therapies against CREBBP-mutant lymphomas, where HDAC3-targeted therapy has been suggested as a precision approach .

What are the optimal sample preparation methods for preserving CREBBP acetylation when using the K1535 antibody?

Acetylation is a labile post-translational modification that requires careful sample handling to preserve. For optimal detection with Acetyl-CREBBP (K1535) Antibody, consider these methodological recommendations:

Cell/Tissue Lysis Protocol:

• Buffer composition:

  • Use RIPA or NP-40 based buffers supplemented with:

    • HDAC inhibitors: 1-5 μM trichostatin A, 5-10 mM sodium butyrate

    • Deacetylase inhibitors: 5-10 mM nicotinamide (for sirtuins)

    • Protease inhibitors: Complete protease inhibitor cocktail (1X)

    • Phosphatase inhibitors: 1 mM sodium orthovanadate, 10 mM sodium fluoride

• Temperature control:

  • Maintain samples at 4°C throughout processing

  • Avoid freeze-thaw cycles which can lead to acetylation loss

  • Process samples immediately after collection when possible

• Nuclear extraction considerations:

  • Since CREBBP primarily functions in the nucleus, nuclear extraction protocols often yield better results

  • Use gentle detergent-based methods rather than mechanical disruption

  • Include 300-400 mM NaCl to ensure release of chromatin-bound CREBBP

Fixation for Immunohistochemistry/Immunofluorescence:

• Brief fixation (10-15 minutes) with 4% paraformaldehyde is preferred

• Avoid over-fixation which can mask epitopes

• Consider antigen retrieval methods (citrate buffer, pH 6.0) to improve signal

Protein Preservation Table:

These technical considerations ensure that the acetylation status of CREBBP at K1535 is accurately preserved and detected in experimental systems.

How can Acetyl-CREBBP (K1535) Antibody be used to investigate the impact of CREBBP mutations on acetylation status?

CREBBP mutations are frequently observed in various cancers, particularly in relapsed childhood ALL and lymphomas. Acetyl-CREBBP (K1535) Antibody provides a valuable tool for investigating how these mutations affect CREBBP's acetylation status and function:

Experimental Approaches:

• Mutation model systems:

  • Generate cell lines expressing common CREBBP mutations found in cancer

  • Compare K1535 acetylation levels between wild-type and mutant CREBBP

  • Correlate acetylation changes with functional outcomes (e.g., histone acetylation, target gene expression)

• Patient-derived xenograft (PDX) models:

  • Use PDX models of ALL or lymphoma with known CREBBP mutation status

  • Apply Acetyl-CREBBP (K1535) Antibody to assess acetylation patterns

  • Compare results with clinical outcomes and response to therapies

• Domain-specific mutation analysis:

  • Investigate how mutations in different CREBBP domains affect K1535 acetylation

  • Focus on HAT domain, bromodomain, and KIX domain mutations

  • Determine whether mutation location influences K1535 accessibility to acetylation machinery

Research Implications:

Studies have shown that CREBBP loss-of-function results in focal depletion of enhancer H3K27 acetylation and aberrant transcriptional silencing of genes that regulate B-cell signaling and immune responses, including class II MHC . By examining K1535 acetylation in different CREBBP mutant contexts, researchers can:

• Determine whether specific mutations affect CREBBP's auto-acetylation or its acetylation by other HATs

• Assess whether K1535 acetylation status correlates with CREBBP's ability to acetylate downstream targets

• Identify potential therapeutic strategies based on restoring normal acetylation patterns

HDAC3 inhibition has been shown to rescue repression of enhancers and corresponding genes in CREBBP-mutant lymphomas , suggesting that modulating acetylation dynamics represents a promising therapeutic approach.

What quantitative approaches can be used to analyze data generated with Acetyl-CREBBP (K1535) Antibody?

Quantitative analysis of data generated with Acetyl-CREBBP (K1535) Antibody requires rigorous methodological approaches to ensure reproducibility and statistical validity:

Western Blot Quantification:

• Normalization strategies:

  • Normalize to total CREBBP levels first, then to loading controls (β-actin, GAPDH)

  • Use internal reference samples across different blots for inter-experimental comparisons

  • Apply rolling ball background subtraction for densitometry

• Statistical analysis:

  • Perform minimum of three biological replicates

  • Apply appropriate statistical tests (t-test for two conditions, ANOVA for multiple)

  • Report data as fold change relative to control conditions

ChIP-seq Data Analysis:

• Peak calling and quality metrics:

  • Use MACS2 with input control for peak calling (recommended parameters: q-value < 0.01)

  • Apply IDR (Irreproducible Discovery Rate) analysis for replicate consistency

  • Calculate FRiP (Fraction of Reads in Peaks) score (>1% considered acceptable)

• Differential binding analysis:

  • Compare acetylated CREBBP binding between conditions using DiffBind or similar tools

  • Apply normalization to total CREBBP ChIP-seq data

  • Perform pathway enrichment analysis on differentially bound regions

Immunofluorescence Quantification:

• Single-cell analysis:

  • Measure nuclear vs. cytoplasmic signal intensity

  • Calculate coefficient of variation across cell populations

  • Use machine learning approaches for pattern recognition in heterogeneous samples

• Colocalization metrics:

  • Calculate Pearson's correlation coefficient for colocalization with other factors

  • Apply Manders' overlap coefficient for partial colocalization assessment

  • Use distance-based metrics for proximity analysis

Reproducibility Considerations:

How might Acetyl-CREBBP (K1535) Antibody contribute to understanding CREBBP's role in aging and age-related diseases?

CREBBP has been implicated in aging processes and age-related diseases, presenting opportunities for using Acetyl-CREBBP (K1535) Antibody in gerontology research:

CREBBP has been linked to human aging processes as a transcriptional regulatory protein that acetylates histones and mediates cAMP-gene regulation . Its important roles in transcriptional regulation and its large number of interacting partners suggest CREBBP might potentially be involved in some aspects of aging .

Research Opportunities:

• Age-dependent acetylation analysis:

  • Compare K1535 acetylation patterns across different age groups in various tissues

  • Correlate changes with markers of cellular senescence and tissue function

  • Investigate relationships between CREBBP acetylation and age-related epigenetic drift

• Intervention studies:

  • Examine how anti-aging interventions (caloric restriction, exercise, senolytics) affect CREBBP K1535 acetylation

  • Test whether HDAC inhibitors can restore youthful CREBBP acetylation patterns in aged tissues

  • Investigate the impact of metabolism-influencing drugs on CREBBP acetylation

• Disease-specific investigations:

  • Study K1535 acetylation in age-related conditions where CREBBP function is implicated

  • Focus on neurodegenerative disorders, metabolic diseases, and age-related cancers

  • Assess whether acetylation status correlates with disease progression or response to therapy

CREBBP heterozygous animals exhibit lipodystrophy, have increased insulin and leptin sensitivity, and appear to be protected from weight gain induced by a high-fat diet . These phenotypes suggest that CREBBP acetylation status may influence metabolic health during aging, making it an attractive target for investigation in age-related metabolic disorders.

What emerging technologies might enhance the utility of Acetyl-CREBBP (K1535) Antibody in future research?

As technology evolves, several emerging methodologies show promise for expanding the applications of Acetyl-CREBBP (K1535) Antibody:

Single-Cell Applications:

• Single-cell ChIP-seq:

  • Apply microfluidic-based approaches for single-cell resolution of acetylated CREBBP binding

  • Identify cell-type-specific functions and heterogeneity within populations

  • Combine with single-cell RNA-seq for direct correlation with gene expression

• CUT&Tag adaptations:

  • Develop Acetyl-CREBBP (K1535) Antibody protocols for CUT&Tag applications

  • Achieve higher resolution and lower background than traditional ChIP-seq

  • Require fewer cells for robust detection of acetylation patterns

Spatial Biology Approaches:

• Spatial transcriptomics integration:

  • Combine Acetyl-CREBBP (K1535) immunohistochemistry with spatial transcriptomics

  • Map acetylation patterns to specific tissue microenvironments

  • Correlate with spatially resolved gene expression profiles

• Multiplex imaging:

  • Develop cyclic immunofluorescence protocols including Acetyl-CREBBP (K1535) Antibody

  • Achieve simultaneous detection of multiple acetylation marks and signaling pathways

  • Create comprehensive spatial maps of acetylation networks

Proteomics Innovations:

• Targeted mass spectrometry:

  • Develop parallel reaction monitoring (PRM) assays for K1535 acetylation quantification

  • Achieve absolute quantification independent of antibody-based methods

  • Identify additional PTMs that co-occur with K1535 acetylation

• Proximity labeling:

  • Use BioID or APEX2 fusions with CREBBP to identify proteins interacting with acetylated CREBBP

  • Compare interactomes of wild-type vs. K1535R mutant CREBBP

  • Discover acetylation-dependent protein-protein interactions

These technological innovations will expand the utility of Acetyl-CREBBP (K1535) Antibody beyond current applications, offering deeper insights into the biological significance of CREBBP acetylation in health and disease.