This antibody is instrumental in studying histone H1.2 acetylation, which influences chromatin compaction and transcriptional regulation.
A protocol example includes:
Fixation: 4% formaldehyde.
Permeabilization: 0.2% Triton X-100.
Blocking: 10% normal goat serum.
Primary Antibody: Incubated at 4°C overnight (1:15 dilution in 1% BSA) .
Detection: Biotinylated secondary antibody + HRP-conjugated streptavidin-phycoerythrin system.
Example Use Case: Detection of K89 acetylation in HeLa cells treated with sodium butyrate, a histone deacetylase inhibitor .
Validated for quantitative analysis of acetylated H1.2 in lysates or recombinant proteins.
Acetylation of linker histones like H1.2 is linked to chromatin decondensation and transcriptional activation. K89 acetylation may:
Regulate Nucleosome Stability: Acetylation neutralizes the positive charge on lysine, reducing DNA-histone interaction.
Influence Gene Expression: Alters chromatin accessibility for transcription factors .
Participate in Apoptosis: H1.2 translocates to the cytosol during apoptosis, activating pro-apoptotic proteins like Bak .
Sequence Homology: H1 variants share 74–87% amino acid identity, complicating epitope targeting .
PTM Complexity: Multiple post-translational modifications (e.g., phosphorylation, methylation) on H1 tails may interfere with antibody binding .
Reactivity: Confirmed for human samples; cross-reactivity with other species (e.g., mouse, rat) not reported .
Controls: Use non-acetylated H1.2 (e.g., CSB-PA010378PA89nacHU) as a negative control .
Below is a selection of antibodies targeting distinct H1.2 modifications, highlighting K89 acetylation’s specificity:
Antibody Code | Target Modification | Applications |
---|---|---|
CSB-PA010378PA16acHU | Acetyl-K16 | ELISA, ICC, ChIP |
CSB-PA010378PA62acHU | Acetyl-K62 | ELISA, ICC, ChIP |
CSB-PA010378PA89acHU | Acetyl-K89 | ELISA, ICC |
CSB-PA010378PA96acHU | Acetyl-K96 | ELISA, WB, ChIP |
CSB-PA010378PA158ncrHU | Crotonyl-K158 | ELISA, ICC, ChIP |
Source: CUSABIO Antibody Catalog .
Chromatin Remodeling: Acetylation at K89 may disrupt H1.2’s interaction with linker DNA, promoting open chromatin states .
Disease Implications: Dysregulated H1 acetylation is linked to cancer and developmental disorders, though K89-specific roles remain understudied .
Methodological Advances: The antibody’s use in ICC enables spatial mapping of acetylation in cellular contexts, complementing bulk analysis techniques like MS .
Histone H1 protein binds to linker DNA between nucleosomes, forming the chromatin fiber. These histones are crucial for condensing nucleosome chains into higher-order structures. Additionally, they regulate individual gene transcription through chromatin remodeling, nucleosome spacing, and DNA methylation.
Histone H1.2 and related functions:
The acetylation of HIST1H1C at lysine 89 (K89) represents a specific post-translational modification that can significantly alter the protein's function in chromatin organization and transcriptional regulation mechanisms . This particular modification site offers researchers a precise molecular target for investigating how histone modifications influence higher-order chromatin structure beyond the core nucleosome . Research indicates that histone variants and their modifications, including HIST1H1C acetylation, are involved in various disease processes, as evidenced by studies showing HIST1H1C's role in diabetic retinopathy development . The K89 site is of particular interest because modifications at this position may influence HIST1H1C's interaction with both DNA and other nuclear proteins, potentially altering downstream signaling pathways that regulate autophagy and inflammatory responses . Understanding the specific effects of K89 acetylation provides critical insights into the molecular mechanisms by which epigenetic modifications influence gene expression patterns and cellular responses to environmental stressors, such as high glucose conditions in diabetic complications .
The Acetyl-HIST1H1C (K89) antibody serves as a valuable tool for multiple research applications, including enzyme-linked immunosorbent assay (ELISA), immunocytochemistry (ICC), Western blotting (WB), immunohistochemistry (IHC), and immunoprecipitation (IP) . In epigenetic research, this antibody allows for specific detection of acetylation at the K89 position of HIST1H1C, enabling researchers to investigate how this modification changes under various experimental conditions or disease states . The antibody has been employed in studies examining the relationship between histone modifications and cellular processes such as autophagy, particularly in the context of diabetic retinopathy and other pathological conditions . Using this antibody, researchers can perform quantitative analysis of HIST1H1C acetylation levels in different tissues or cell types, facilitating comparative studies across experimental models . Additionally, the antibody can be utilized in chromatin immunoprecipitation experiments to identify genomic regions associated with acetylated HIST1H1C, providing insights into the specific genes regulated by this modification .
For optimal results with Acetyl-HIST1H1C (K89) antibody in immunocytochemistry applications, researchers should use a dilution range of 1:10 to 1:100, as recommended by antibody manufacturers . When preparing samples for Western blot or immunohistochemistry, proper fixation protocols are essential—typically using 4% paraformaldehyde for cell cultures or formalin-fixed paraffin-embedded tissues for histological sections, followed by appropriate antigen retrieval techniques to expose the K89 epitope . The antibody performs optimally in standard buffer conditions such as PBS with pH 7.4, and inclusion of 50% glycerol and 0.03% Proclin 300 as preservatives helps maintain antibody stability during storage and use . For ELISA applications, researchers should calibrate antibody concentrations through preliminary titration experiments to determine the optimal working concentration that provides maximum specific signal with minimal background . Long-term storage should be at -20°C or -80°C to preserve antibody activity, with avoidance of repeated freeze-thaw cycles that could degrade the antibody and compromise experimental results .
A comprehensive validation strategy for Acetyl-HIST1H1C (K89) antibody should begin with Western blot analysis using positive control samples known to express acetylated HIST1H1C, confirming the antibody detects a band of appropriate molecular weight (approximately 21-23 kDa) . Researchers should perform peptide competition assays using both acetylated and non-acetylated K89 peptides to demonstrate that only the acetylated peptide blocks antibody binding, confirming modification-specific recognition . Validation experiments should include genetic controls, such as HIST1H1C knockout cell lines or cells with CRISPR-engineered K89R mutations (preventing acetylation at that site), which should show absent or significantly reduced signal compared to wild-type cells . Cross-reactivity testing against other histone H1 variants is essential to ensure the antibody specifically recognizes HIST1H1C and not closely related family members with similar sequence motifs around the K89 position . Additionally, researchers should validate antibody performance across multiple techniques (WB, IHC, ELISA) and using different cell types or tissues to confirm consistent specificity and performance across experimental contexts and biological systems .
When designing experiments with Acetyl-HIST1H1C (K89) antibody, positive controls should include samples treated with histone deacetylase inhibitors like trichostatin A or sodium butyrate, which increase global histone acetylation levels including at HIST1H1C K89 . Cells or tissues with known high expression of acetylated HIST1H1C, such as certain cancer cell lines or embryonic tissues with active chromatin remodeling, serve as excellent positive controls for validating antibody performance . Negative controls should include HIST1H1C knockout models generated through CRISPR-Cas9 gene editing, or cells where HIST1H1C expression has been silenced using specific siRNA, as demonstrated in diabetic retinopathy research . Samples treated with histone acetyltransferase inhibitors that reduce HIST1H1C acetylation can serve as partial negative controls, showing reduced signal intensity compared to untreated samples . Additionally, technical negative controls should be performed by omitting the primary antibody during immunostaining procedures, or by using isotype-matched irrelevant antibodies to establish baseline non-specific binding levels and ensure staining specificity .
A multi-modal approach to studying HIST1H1C acetylation should begin with immunoblotting to quantify total acetylated HIST1H1C (K89) levels in cell or tissue lysates, establishing baseline expression and changes under experimental conditions . This should be paired with immunofluorescence or immunohistochemistry to visualize the subcellular localization of acetylated HIST1H1C, determining whether the modification affects nuclear distribution patterns or association with specific chromatin regions . Chromatin immunoprecipitation (ChIP) using the Acetyl-HIST1H1C (K89) antibody followed by sequencing (ChIP-seq) can identify genomic regions associated with this modified histone, revealing potential genes regulated by this specific acetylation event . Mass spectrometry-based approaches complement antibody-based detection by providing unbiased identification and quantification of HIST1H1C post-translational modifications, including acetylation at K89 and other sites, as mentioned in acetylomics procedures . To establish functional relationships, researchers should correlate acetylation data with gene expression analysis through RNA-Seq, examining how changes in HIST1H1C K89 acetylation correspond to alterations in transcriptional profiles, particularly for genes involved in processes like autophagy regulation .
Research has demonstrated that HIST1H1C/H1.2 plays a critical role in autophagy regulation through an epigenetic mechanism involving the maintenance of H4K16 deacetylation status . In diabetic retinopathy models, HIST1H1C expression is significantly upregulated in the retinas of type 1 diabetic rodents, correlating with increased autophagy markers and suggesting a mechanistic link between this histone variant and autophagy dysregulation in diabetic conditions . Mechanistically, HIST1H1C overexpression upregulates SIRT1 and HDAC1, two histone deacetylases that maintain the deacetylation status of H4K16, which subsequently leads to upregulation of autophagy-related proteins (ATGs) including ATG12-ATG5 complex, ATG7, ATG3, and promotes LC3B-I to LC3B-II conversion . Experimental evidence supports this regulatory pathway, as cells overexpressing HIST1H1C show enhanced autophagic flux, demonstrated by reduced SQSTM1/p62 levels (a known autophagy substrate) and increased LC3B-II formation, effects that were further enhanced by autophagy inhibitors like chloroquine and bafilomycin A1 . Importantly, in vivo studies using AAV-mediated HIST1H1C overexpression in retinas recapitulated pathological changes characteristic of early diabetic retinopathy, including increased autophagy, inflammation, glial activation, and neuron loss, while knockdown of HIST1H1C using siRNA significantly attenuated these diabetes-induced pathological changes .
To comprehensively investigate the relationship between HIST1H1C acetylation and autophagy, researchers should employ genetic manipulation techniques such as plasmid-based overexpression of wild-type HIST1H1C versus acetylation-deficient (K89R) or acetylation-mimetic (K89Q) mutants to directly assess how this specific modification affects autophagy pathways . Autophagy flux assays using LC3B-II accumulation with and without lysosomal inhibitors (such as chloroquine or bafilomycin A1), combined with SQSTM1/p62 degradation analysis, provide quantitative measures of how HIST1H1C acetylation status influences the rate and efficiency of autophagy . Co-immunoprecipitation experiments can identify protein-protein interactions between acetylated HIST1H1C and autophagy regulatory proteins or chromatin modifiers like SIRT1 and HDAC1, elucidating the molecular mechanisms by which acetylation affects autophagy signaling pathways . Chromatin immunoprecipitation followed by sequencing (ChIP-seq) using Acetyl-HIST1H1C (K89) antibody can map the genomic binding sites of specifically acetylated HIST1H1C, revealing direct transcriptional targets that may include autophagy-related genes . Additionally, researchers should employ advanced imaging techniques such as fluorescence microscopy with GFP-LC3 to visualize and quantify autophagic vesicles in relation to HIST1H1C acetylation status, as demonstrated in studies showing increased percentage of autophagic cells from 8% to 21% upon HIST1H1C overexpression .
To assess HIST1H1C's influence on inflammation, researchers should employ quantitative PCR and ELISA to measure expression levels of key inflammatory cytokines (IL-1β, IL-6, TNF-α) and chemokines following HIST1H1C manipulation through overexpression or knockdown, as demonstrated in diabetic retinopathy models . Cell toxicity evaluations should include multiple complementary assays such as MTT or WST-1 for metabolic activity, lactate dehydrogenase (LDH) release for membrane integrity, and annexin V/propidium iodide staining with flow cytometry to distinguish between apoptotic and necrotic cell death pathways following HIST1H1C modulation . Researchers should implement in vitro stress models that mimic disease conditions, such as high glucose treatment to simulate diabetes, and examine how HIST1H1C levels affect cellular responses to these stressors, particularly focusing on inflammation and viability outcomes . For in vivo assessment, techniques like AAV-mediated HIST1H1C overexpression or siRNA-mediated knockdown in animal models, followed by immunohistochemical analysis of tissue sections for inflammatory markers, glial activation (GFAP), and neuronal loss, provide comprehensive evaluation of HIST1H1C's impact on tissue inflammation and integrity . Mechanistic insights can be gained by examining HIST1H1C's effects on key inflammatory signaling pathways through Western blot analysis of NF-κB activation, MAPK signaling, and NLRP3 inflammasome components, connecting histone modifications to downstream inflammatory cascades .
To investigate interactions between HIST1H1C and histone deacetylases (HDACs), researchers should employ co-immunoprecipitation assays using Acetyl-HIST1H1C (K89) antibody followed by Western blotting for HDAC1, HDAC2, and SIRT1 to determine physical associations between these proteins in native chromatin contexts . Chromatin immunoprecipitation (ChIP) experiments can be designed to assess co-occupancy of HIST1H1C and HDACs at specific genomic loci, revealing functional relationships in the regulation of target genes involved in processes such as autophagy . Using CRISPR-Cas9 technology to generate HDAC1 or HDAC2 knockout cell lines, as described in the literature, researchers can evaluate how the absence of specific HDACs affects HIST1H1C acetylation status at K89 and other residues, establishing dependency relationships . In vitro deacetylation assays using purified HDACs and acetylated HIST1H1C substrate can directly test which HDAC enzymes are capable of removing the acetyl group from K89, providing biochemical evidence for enzyme-substrate specificity . Additionally, researchers should implement pharmacological approaches using isoform-selective HDAC inhibitors to distinguish the contributions of different HDACs to HIST1H1C acetylation status in cellular contexts, complementing genetic approaches for comprehensive mechanistic understanding .
When encountering cell type-specific variations in HIST1H1C acetylation patterns, researchers should first consider the baseline expression levels of HIST1H1C itself across the cell types being compared, as different tissues naturally express varying amounts of this histone variant, which may influence the detectable acetylation signal . Differences in acetylation patterns may reflect tissue-specific epigenetic landscapes, so researchers should correlate HIST1H1C K89 acetylation data with expression profiles of relevant histone acetyltransferases (HATs) and histone deacetylases (HDACs) that could be differentially expressed across cell types . The functional significance of variable acetylation patterns should be interpreted in the context of cell type-specific processes, such as comparing neuronal cells to glial cells in retinal tissue, where HIST1H1C may play distinct roles in autophagy regulation and responses to stress conditions like high glucose . Researchers should also consider the cell cycle status and proliferation rates of different cell populations, as histone modifications including HIST1H1C acetylation can fluctuate throughout the cell cycle, potentially explaining some observed variations between rapidly dividing and post-mitotic cell types . When making comparisons across cell types, it is critical to normalize acetylation data to total HIST1H1C protein levels rather than comparing absolute acetylation signals, ensuring that observed differences reflect actual changes in the proportion of HIST1H1C molecules that are acetylated at K89 .
One frequent challenge is insufficient signal strength, which can be addressed by optimizing antibody concentration (trying a range from 1:10 to 1:100 for ICC applications), implementing more sensitive detection systems such as tyramide signal amplification, or enhancing antigen retrieval methods for formalin-fixed samples . Background staining issues can be mitigated by increasing blocking time using 5% BSA or normal serum, performing more thorough washing steps between antibody incubations, or using specialized blocking reagents that reduce non-specific binding to highly charged histone proteins . Cross-reactivity with other acetylated proteins can complicate data interpretation, but this can be addressed by including appropriate controls such as acetylation-deficient mutants (K89R) or performing peptide competition assays with acetylated and non-acetylated K89 peptides to confirm signal specificity . Batch-to-batch variability in antibody performance is another common challenge; researchers should maintain consistent lot numbers for longitudinal studies or perform side-by-side validation of new antibody lots against previous ones using identical positive control samples . In complex tissues with variable HIST1H1C expression, detection sensitivity may vary; this can be improved by using signal amplification methods, adjusting exposure settings in imaging systems, or employing more sensitive techniques like proximity ligation assay when studying cells with naturally low HIST1H1C expression levels .
To differentiate between direct and indirect effects of HIST1H1C acetylation on autophagy, researchers should implement time-course experiments following HIST1H1C overexpression or acetylation modification to establish the temporal sequence of molecular events, determining whether changes in autophagy markers occur before or after alterations in other signaling pathways . Site-directed mutagenesis approaches generating acetylation-mimetic (K89Q) and acetylation-deficient (K89R) HIST1H1C mutants allow researchers to isolate the specific contribution of K89 acetylation status to autophagy regulation, independent of other HIST1H1C functions . Researchers should employ chromatin immunoprecipitation followed by sequencing (ChIP-seq) using Acetyl-HIST1H1C (K89) antibody to identify genomic regions directly bound by acetylated HIST1H1C, correlating these binding patterns with transcriptional changes in autophagy-related genes to establish direct regulatory relationships . Pharmacological approaches using specific inhibitors of intermediate signaling components (such as SIRT1 or HDAC1 inhibitors) can determine whether blocking these factors prevents HIST1H1C-induced autophagy, helping to delineate the complete signaling pathway from histone modification to autophagosome formation . Additionally, mechanistic studies should include protein-protein interaction analyses using techniques like proximity ligation assay or FRET to determine whether acetylated HIST1H1C directly interacts with autophagy machinery components or exclusively functions through transcriptional regulation of autophagy genes .
When confronted with contradictory results in HIST1H1C acetylation studies, researchers should first evaluate methodological differences between studies, including antibody sources, detection techniques, and experimental models, as these factors can significantly influence outcomes and interpretations . A systematic comparison of experimental conditions—particularly cell types, culture conditions, and stress parameters—is essential, as HIST1H1C acetylation responses may be context-dependent and vary considerably between different physiological or pathological states . Researchers should consider the temporal dynamics of acetylation changes by implementing detailed time-course experiments, as contradictory findings might result from examining different time points in a dynamic process where HIST1H1C acetylation patterns evolve over time following stimulation . Multi-omics approaches combining acetylomics with transcriptomics and proteomics can provide a comprehensive view of how HIST1H1C acetylation integrates with broader cellular processes, potentially reconciling seemingly contradictory observations by placing them in a wider biological context . Additionally, collaborative cross-validation studies between laboratories using standardized protocols and reagents, including shared positive and negative controls, can help determine whether contradictions stem from biological variability or technical differences, ultimately strengthening confidence in reproducible findings .
Advanced mass spectrometry-based proteomic approaches represent a frontier for comprehensively mapping the full spectrum of post-translational modifications on HIST1H1C, enabling researchers to identify novel modification sites and potential crosstalk between acetylation at K89 and other modifications such as phosphorylation, methylation, and ubiquitination . Cutting-edge genomic engineering techniques, including base editing and prime editing, offer precise tools for introducing specific modifications at the endogenous HIST1H1C locus, allowing researchers to study the functional consequences of these modifications in their native chromatin context without overexpression artifacts . Single-cell epigenomic profiling technologies are emerging as powerful approaches to characterize HIST1H1C modification heterogeneity across individual cells within tissues, providing insights into cell-to-cell variation in histone modification patterns that may correspond to functional diversity in processes like autophagy regulation . Cryo-electron microscopy and structural biology approaches can reveal how specific modifications, including but not limited to K89 acetylation, affect HIST1H1C's three-dimensional structure and its interactions with DNA and other nuclear proteins, providing mechanistic insights at atomic resolution . Additionally, the development of modification-specific intrabodies and FRET-based biosensors promises to enable real-time monitoring of HIST1H1C modification dynamics in living cells, allowing researchers to observe how these modifications change in response to stimuli such as metabolic stress or drug treatments .
Based on research demonstrating HIST1H1C's role in promoting autophagy, inflammation, and cell toxicity in diabetic retinopathy, therapeutic strategies targeting HIST1H1C expression or its post-translational modifications could potentially interrupt the pathological cascade leading to retinal damage in diabetic patients . Small molecule inhibitors designed to specifically modulate the enzymes responsible for HIST1H1C acetylation or deacetylation, particularly at the K89 position, could provide a targeted approach to normalizing autophagy levels in the retina without broadly affecting other epigenetic regulatory mechanisms . RNA interference-based therapeutics, similar to the siRNA approach that successfully attenuated diabetes-induced pathological changes in experimental models, represent a promising avenue for clinical translation, potentially through retina-specific delivery systems that could locally reduce HIST1H1C expression . Innovative epigenetic editing approaches utilizing modified CRISPR systems (such as dCas9 fused to histone modification enzymes) could enable precise manipulation of HIST1H1C acetylation status at specific genomic loci, potentially restoring normal gene expression patterns disrupted in diabetic conditions . Development of peptide or aptamer-based drugs that bind directly to HIST1H1C and interfere with its interactions with chromatin or regulatory proteins could provide another therapeutic strategy, potentially blocking pathological functions while preserving physiological roles .
Integration of acetylomics with transcriptomics can reveal how changes in HIST1H1C acetylation patterns correlate with global gene expression profiles, identifying the specific gene networks regulated by this histone modification in normal development and disease states like diabetic retinopathy . Combining ChIP-seq data for Acetyl-HIST1H1C (K89) with ATAC-seq or DNase-seq can elucidate how this specific modification influences chromatin accessibility, providing insights into the mechanistic basis for its effects on transcriptional regulation and cellular processes like autophagy . Metabolomic profiling in conjunction with HIST1H1C acetylation studies can reveal how changes in cellular metabolism—such as those occurring in diabetes—might influence the availability of acetyl-CoA as a substrate for histone acetylation, establishing links between metabolic state and epigenetic regulation . Proteomics approaches focusing on HIST1H1C interactome analysis can identify the network of proteins that specifically interact with acetylated versus non-acetylated HIST1H1C, potentially uncovering novel effector proteins that mediate downstream responses . Implementation of spatial multi-omics technologies in tissues like the retina can map the distribution of HIST1H1C modifications across different cell types and anatomical regions, correlating these patterns with local gene expression and tissue pathology to provide context-specific insights into HIST1H1C function in complex tissues .
Machine learning algorithms can be trained on large datasets of histone modification patterns to predict sites of HIST1H1C acetylation under various cellular conditions, potentially identifying novel regulatory sites beyond K89 that may have functional significance in processes like autophagy regulation . Deep learning approaches applied to imaging data can enhance the analysis of immunofluorescence experiments using Acetyl-HIST1H1C (K89) antibody, enabling more sensitive and objective quantification of signal intensity and subcellular localization patterns across different experimental conditions . Artificial intelligence can accelerate the development of selective small molecule modulators of HIST1H1C acetylation through in silico screening and molecular dynamics simulations, predicting compounds that might specifically target enzymes regulating K89 acetylation for potential therapeutic applications . Network analysis algorithms can integrate multi-omics data to construct comprehensive regulatory networks centered on HIST1H1C, identifying key nodes and feedback loops that might serve as intervention points for modulating pathological processes in diseases like diabetic retinopathy . Additionally, natural language processing tools can systematically analyze the scientific literature on histone modifications to identify overlooked connections between HIST1H1C acetylation and various cellular processes or disease states, generating novel hypotheses for experimental validation and accelerating knowledge discovery in this complex field .