CTBP1 (Ab-422) Antibody

What is CTBP1 (Ab-422) Antibody and what epitope does it recognize?

CTBP1 (Ab-422) Antibody is a polyclonal antibody raised in rabbits against a synthesized non-phosphopeptide derived from human CTBP1 around the phosphorylation site of serine 422 (A-P-S(p)-P-G). This antibody specifically detects endogenous levels of total CTBP1 protein, making it valuable for studying CTBP1 expression and function . The antibody targets a region of interest in CTBP1 that may undergo post-translational modifications, allowing researchers to investigate the native protein without being restricted to detecting only phosphorylated forms.

What are the validated applications for CTBP1 (Ab-422) Antibody?

The CTBP1 (Ab-422) Antibody has been validated for multiple experimental applications. These include Enzyme-Linked Immunosorbent Assay (ELISA), Western Blotting (WB), and Immunohistochemistry (IHC) . For Western Blotting, the recommended dilution range is 1:500-1:3000, while for Immunohistochemistry, the optimal dilution range is 1:50-1:100. The antibody detects a band at approximately 48 kDa in SDS-PAGE, corresponding to the molecular weight of CTBP1 . These validated applications make the antibody versatile for detecting CTBP1 across multiple experimental platforms.

What is the proper storage and handling procedure for CTBP1 (Ab-422) Antibody?

For optimal performance and longevity, CTBP1 (Ab-422) Antibody should be stored at -20°C . The antibody is formulated in phosphate buffered saline (without Mg²⁺ and Ca²⁺), pH 7.4, containing 150mM NaCl, 0.02% sodium azide, and 50% glycerol . When handling the antibody, avoid repeated freeze-thaw cycles as this can compromise antibody activity. For experiments, aliquot the antibody upon receipt to minimize the number of freeze-thaw cycles. The concentration of the antibody is 1.0mg/ml, which allows for appropriate dilution calculations for various applications .

What is the biological function of CTBP1 and why is it of interest to researchers?

CTBP1 (C-terminal binding protein 1) functions as a transcriptional corepressor targeting diverse transcription regulators such as GLIS2 and BCL6 . It possesses dehydrogenase activity and is involved in controlling the equilibrium between tubular and stacked structures in the Golgi complex. CTBP1 also plays a role in brown adipose tissue (BAT) differentiation . Of particular interest to cancer researchers, CTBP1 has been implicated in tumor biology, including roles in tumor invasion and drug resistance mechanisms . Additionally, CTBP1 interacts with nuclear receptors in a ligand-dependent manner, contributing to transcriptional regulation in hormone-responsive tissues .

How should CTBP1 (Ab-422) Antibody performance be validated in new experimental systems?

When introducing CTBP1 (Ab-422) Antibody to a new experimental system, validation should include multiple steps. First, perform Western blotting with positive and negative controls (e.g., CTBP1 knockdown cells) to confirm specificity and appropriate molecular weight detection (48 kDa) . For IHC applications, include tissue sections known to express CTBP1 alongside negative controls. Peptide competition assays can provide additional validation by demonstrating signal reduction when the antibody is pre-incubated with the immunizing peptide. For advanced validation, consider using orthogonal methods such as mass spectrometry to confirm antibody specificity, or parallel detection with alternative CTBP1 antibodies targeting different epitopes to corroborate findings.

What are the recommended protocols for immunoprecipitation using CTBP1 (Ab-422) Antibody?

For immunoprecipitation with CTBP1 (Ab-422) Antibody, incubate 1 mg of cell lysate protein with the antibody at 4°C overnight . As a control, parallel samples should be incubated with normal rabbit IgG. Following antibody incubation, add protein G-Sepharose beads and incubate at 4°C for 2 hours. Wash the immunoprecipitates at least 4 times with NP-40 lysis buffer to remove non-specific binding. Elute bound proteins by boiling for 5 minutes in Laemmli sample buffer, then separate by SDS-PAGE followed by Western blotting . When analyzing protein-protein interactions involving CTBP1, consider including detergents and salt concentrations that preserve relevant interactions while reducing background.

What controls should be included when using CTBP1 (Ab-422) Antibody in chromatin immunoprecipitation (ChIP) assays?

In ChIP assays using CTBP1 (Ab-422) Antibody, include the following controls: (1) Input control: a sample of chromatin before immunoprecipitation to normalize for differences in starting material; (2) Negative control: immunoprecipitation with normal rabbit IgG to account for non-specific binding; (3) Positive control: primers targeting a genomic region known to be bound by CTBP1, such as the MDR1 promoter region ; (4) Negative locus control: primers targeting a genomic region not expected to bind CTBP1. Additionally, include biological replicates and, when possible, validate findings using alternative methods such as EMSA (electrophoretic mobility shift assay) . For studies examining CTBP1 binding dynamics, consider performing ChIP under different conditions (e.g., with and without hormone treatment if studying nuclear receptor-mediated pathways).

How can CTBP1 (Ab-422) Antibody be utilized to study CTBP1's role in transcriptional regulation?

CTBP1 (Ab-422) Antibody can be employed in chromatin immunoprecipitation (ChIP) assays to investigate CTBP1 binding to specific gene promoters, as demonstrated in studies of the MDR1 gene . This approach allows researchers to map CTBP1 genomic binding sites and correlate them with transcriptional outputs. For more comprehensive analysis, the antibody can be used in ChIP-seq experiments to profile genome-wide CTBP1 binding patterns. Additionally, the antibody can be applied in co-immunoprecipitation experiments to identify CTBP1 interaction partners within transcriptional complexes, including histone deacetylases (HDACs) and the Sin3A corepressor complex . To study CTBP1's function in real-time, researchers can combine the antibody with proximity ligation assays or FRET-based approaches for visualizing dynamic interactions with other transcriptional regulators.

What methodologies can be used to investigate the interaction between CTBP1 and long non-coding RNA CTBP1-AS?

To study the interaction between CTBP1 protein and its antisense transcript CTBP1-AS, researchers should consider RNA immunoprecipitation (RIP) assays using CTBP1 (Ab-422) Antibody. This approach can determine whether CTBP1-AS physically interacts with CTBP1 protein. For in-cell visualization of potential co-localization, combine immunofluorescence using the antibody with RNA FISH (fluorescence in situ hybridization) targeting CTBP1-AS. To examine functional relationships, implement parallel knockdown experiments of CTBP1 and CTBP1-AS, followed by RNA-seq and antibody-based protein detection to identify convergent and divergent downstream effects . For detailed molecular interaction analysis, consider using in vitro binding assays with recombinant CTBP1 protein and in vitro transcribed CTBP1-AS, followed by structural studies such as SHAPE (selective 2'-hydroxyl acylation analyzed by primer extension) to map RNA-protein interaction domains.

How can researchers investigate the role of CTBP1 phosphorylation at Ser422 in protein function?

While CTBP1 (Ab-422) Antibody recognizes the region around Ser422 regardless of phosphorylation status, researchers can implement complementary approaches to study the role of Ser422 phosphorylation. First, use phospho-specific antibodies in parallel with the CTBP1 (Ab-422) Antibody to determine the ratio of phosphorylated to total CTBP1. Second, generate site-directed mutants (S422A to prevent phosphorylation or S422D/E to mimic constitutive phosphorylation) and compare their functional properties with wild-type CTBP1 . Third, utilize mass spectrometry following immunoprecipitation with CTBP1 (Ab-422) Antibody to quantify phosphorylation levels under different cellular conditions. Additionally, investigate the kinases responsible for Ser422 phosphorylation, such as cAMP-dependent protein kinase , using kinase inhibitors or knockdown approaches followed by Western blotting with phospho-specific antibodies.

What methods can be used to study CTBP1's contribution to multidrug resistance in cancer?

To investigate CTBP1's role in multidrug resistance, researchers can use CTBP1 (Ab-422) Antibody in several approaches. First, compare CTBP1 expression levels between drug-sensitive and drug-resistant cancer cell lines using Western blotting . Second, perform ChIP assays to examine CTBP1 binding to the MDR1 promoter in response to drug treatment . Third, implement RNAi-mediated silencing of CTBP1 followed by drug sensitivity assays and intracellular drug accumulation measurements to establish the functional relationship between CTBP1 expression and drug resistance . For mechanistic insights, combine reporter gene assays using MDR1 promoter constructs with CTBP1 overexpression or knockdown to assess direct transcriptional effects. Additionally, examine potential post-translational modifications of CTBP1 in response to chemotherapeutic agents that might alter its activity in drug-resistant cells.

How does CTBP1-AS regulate CTBP1 expression in prostate cancer, and how can this be studied?

CTBP1-AS is an androgen-responsive long non-coding RNA that represses CTBP1 expression by recruiting the RNA-binding transcriptional repressor PSF together with histone deacetylases to the CTBP1 promoter . To study this regulatory mechanism, researchers can use CTBP1 (Ab-422) Antibody to monitor CTBP1 protein levels following modulation of CTBP1-AS expression. Northern blot analysis can be employed to detect CTBP1-AS expression in nuclear fractions . ChIP assays using antibodies against histone modifications and HDACs can help characterize the chromatin environment at the CTBP1 promoter in response to CTBP1-AS modulation . For functional studies, researchers should consider xenograft models with CTBP1-AS overexpression or knockdown to assess effects on tumor growth in castration-resistant prostate cancer . Additionally, combined RNA-seq and ChIP-seq approaches can identify global downstream targets affected by the CTBP1-AS/CTBP1 regulatory axis.

What is the relationship between CTBP1 and histone modifications in transcriptional regulation?

CTBP1 interacts with histone deacetylases (HDACs) and contributes to chromatin modification at target gene promoters. Using CTBP1 (Ab-422) Antibody, researchers can perform co-immunoprecipitation experiments to identify CTBP1's association with specific HDAC isoforms (HDAC1, HDAC2, HDAC3, and HDAC8) and the Sin3A corepressor complex . ChIP assays can be used to examine the recruitment of these factors to target gene promoters following CTBP1 modulation. Sequential ChIP (re-ChIP) can determine if CTBP1 and HDACs simultaneously occupy the same genomic regions. To assess functional consequences, researchers should analyze histone modifications (acetylation, methylation) at target promoters in response to CTBP1 knockdown or overexpression . Notably, studies have shown that silencing CTBP1 in MDR1 gene regulation does not affect histone H3 modifications, suggesting context-dependent mechanisms .

How can researchers address potential cross-reactivity with CTBP2 when using CTBP1 (Ab-422) Antibody?

CTBP1 and CTBP2 share significant sequence homology, potentially leading to cross-reactivity concerns. To address this, researchers should validate antibody specificity through several approaches. First, perform Western blotting on samples from CTBP1 and CTBP2 knockdown cells to confirm band-specificity. Second, use recombinant CTBP1 and CTBP2 proteins in dot blot or Western blot analyses to assess potential cross-reactivity. Third, compare staining patterns with validated isoform-specific antibodies in parallel experiments. For critical applications, consider pre-absorbing the antibody with recombinant CTBP2 to remove potentially cross-reactive antibodies. Additionally, complement antibody-based detection with orthogonal approaches such as mass spectrometry or RT-qPCR to distinguish between CTBP1 and CTBP2 expression patterns in your experimental system.

What are common pitfalls in ChIP experiments using CTBP1 (Ab-422) Antibody and how can they be overcome?

Common pitfalls in ChIP experiments with CTBP1 (Ab-422) Antibody include: (1) Insufficient chromatin fragmentation: optimize sonication conditions to achieve fragments of 200-500 bp; (2) High background signal: increase wash stringency and include blocking agents in buffers; (3) Poor enrichment: adjust antibody concentration and chromatin amount, considering that optimal ratios may differ from Western blotting applications; (4) Cell type-specific variations: validate ChIP conditions for each cell type, as CTBP1 binding patterns and abundance may vary; (5) Epitope masking: consider that protein-protein interactions or post-translational modifications might affect antibody accessibility to CTBP1 in the chromatin context . To overcome these challenges, include spike-in controls for normalization, perform pilot experiments with positive control loci known to bind CTBP1 (such as the MDR1 promoter), and consider fixation time adjustments to optimize chromatin preparation.

How can researchers resolve contradictory findings regarding CTBP1's role in cancer progression?

Contradictory findings regarding CTBP1's role in cancer progression, such as its reported tumor-suppressive effects in some contexts and oncogenic properties in others, may stem from several factors . To address these contradictions, researchers should: (1) Characterize CTBP1 expression using CTBP1 (Ab-422) Antibody across diverse cell lines, considering variables such as AR (androgen receptor) status in prostate cancer models; (2) Implement context-specific functional assays, as CTBP1's effects may depend on its interaction partners in different cellular environments; (3) Analyze CTBP1 activity in relation to disease stage, as its function may evolve during cancer progression; (4) Examine post-translational modifications of CTBP1 that might alter its activity; (5) Investigate the balance between CTBP1 and CTBP1-AS expression, particularly in hormone-responsive cancers . For comprehensive analysis, combine antibody-based protein detection with transcriptomic and epigenomic profiling to identify context-specific CTBP1 regulatory networks.

How can CTBP1 (Ab-422) Antibody be utilized in studying CTBP1's role in hormone-responsive cancers?

CTBP1 (Ab-422) Antibody offers valuable applications for investigating CTBP1's function in hormone-responsive cancers. Researchers can use the antibody to compare CTBP1 expression levels between hormone-dependent and castration-resistant prostate cancer models . ChIP experiments can map CTBP1 binding to androgen receptor (AR) target genes and assess how this binding changes in response to hormone treatment or deprivation. Co-immunoprecipitation studies can identify hormone-dependent interactions between CTBP1 and transcriptional regulators such as AR or nuclear receptor corepressors . To understand the CTBP1-AS/CTBP1 regulatory axis, combine antibody-based protein detection with RNA analysis in models representing different stages of hormone-responsive cancer progression. Additionally, xenograft studies with CTBP1 modulation can assess its contribution to tumor growth under normal and hormone-depleted conditions .

What methodologies can be employed to study the relationship between CTBP1 and drug resistance mechanisms beyond MDR1 regulation?

While CTBP1's role in MDR1 regulation is established , researchers can explore broader contributions to drug resistance using CTBP1 (Ab-422) Antibody. Implement proteomics approaches following CTBP1 immunoprecipitation to identify novel interaction partners in drug-resistant cells. Perform ChIP-seq to map genome-wide CTBP1 binding sites in sensitive versus resistant cells, identifying additional target genes beyond MDR1. Use the antibody in tissue microarray analyses to correlate CTBP1 expression with treatment response in patient samples. For functional validation, combine CTBP1 knockdown or overexpression with transcriptomic profiling and drug sensitivity assays across diverse chemotherapeutic agents. Investigate whether CTBP1 contributes to non-MDR1 resistance mechanisms such as DNA damage repair, apoptosis regulation, or cancer stem cell properties through immunofluorescence co-localization studies and pathway-specific functional assays.