NFKB1 (Ab-893) Antibody

What is NFKB1 and what is its biological function?

NFKB1 (Nuclear Factor Kappa B Subunit 1) is a master regulator of immune and inflammatory responses. It encodes a 105 kD protein (p105) that can undergo cotranslational processing by the 26S proteasome to produce a 50 kD protein (p50) . The p105 protein functions as a Rel protein-specific transcription inhibitor, while p50 serves as a DNA binding subunit of the NF-kappa-B (NFKB) protein complex .

NFKB is activated by various stimuli including cytokines, oxidant-free radicals, ultraviolet irradiation, and bacterial or viral products . Upon activation, NFKB translocates to the nucleus and regulates gene expression involved in:

• Inflammation (cytokines, chemokines, adhesion molecules)

• Cell survival (anti-apoptotic proteins like c-IAP-1/2, Bcl-2, Bcl-XL)

• Immune cell development and function

• Cell proliferation (cyclin D1)

In the immune system, NFKB1 facilitates both innate and adaptive responses by regulating T-cell activation, lymphoid organogenesis, and B-cell differentiation and survival .

What is the NFKB1 (Ab-893) Antibody specifically targeting?

The NFKB1 (Ab-893) Antibody specifically targets the phosphorylated serine residue at position 893 (pSer893) of the NFKB1 protein . This phospho-specific antibody is designed to detect endogenous levels of NF-κB p105/p50 only when phosphorylated at this specific serine residue .

The antibody is typically generated using a synthesized peptide derived from human NF-κB p105/p50 around the phosphorylation site of Ser893, with the immunogen corresponding to amino acids in the range of 860-909 . According to one manufacturer, the specific immunogen peptide sequence includes amino acids 891-895 (A-S-S-P-V) from human NFkB-p105 .

This specificity allows researchers to monitor this particular post-translational modification of NFKB1, which represents one of the regulatory mechanisms controlling its function in various cellular contexts.

What are the typical applications for NFKB1 (Ab-893) Antibody in research?

The NFKB1 (Ab-893) Antibody can be utilized in multiple research applications with specific recommended dilution ranges:

Example validation data from manufacturers includes:

• Western blot analysis of various cell lines (HeLa, 293 cells) showing specific detection of phosphorylated NFκB-p105

• Immunohistochemical staining of human breast carcinoma tissue with signal reduction or elimination when blocked with phospho-peptide competition controls

These applications allow researchers to investigate the activation status of NFKB1 in various experimental contexts, including disease models, signaling pathway studies, and drug response assessments.

How does phosphorylation at Ser893 regulate NFKB1 function?

Phosphorylation at Ser893 is one of several post-translational modifications that regulate NFKB1 activity. While the exact mechanisms specific to this phosphorylation site require further investigation, research on NFKB1 phosphorylation indicates several potential regulatory effects:

• Processing regulation: Phosphorylation events can influence the processing of p105 to p50, affecting the availability of the active p50 subunit .

• Signaling pathway integration: Phosphorylation at specific sites occurs in response to various stimuli and can mediate cross-talk between different signaling pathways .

• Protein-protein interactions: Phosphorylation can modify interactions with other transcription factors, coactivators, and regulatory proteins that influence transcriptional activity .

• Nuclear translocation: Phosphorylation states can affect the nuclear entry of NF-κB dimers after release from inhibitory IκB proteins .

• DNA binding affinity: Phosphorylation can modulate the ability of NF-κB complexes to bind to κB sites in target gene promoters .

The study of specific phosphorylation events, including Ser893, is important for understanding the complex regulation of NF-κB signaling in normal physiology and disease states such as immunodeficiency disorders and cancer .

How can NFKB1 (Ab-893) Antibody be used to investigate the relationship between NFKB1 phosphorylation and immunodeficiency disorders?

Recent research has identified heterozygous mutations in the NFKB1 gene as the most common monogenic cause of Common Variable Immunodeficiency (CVID) . The NFKB1 (Ab-893) Antibody can be employed in several methodological approaches to investigate the relationship between NFKB1 phosphorylation and these disorders:

• Patient sample analysis: Compare phosphorylation levels at Ser893 in peripheral blood mononuclear cells (PBMCs) from patients with NFKB1-associated CVID versus healthy controls . This can be performed using:

  • Western blotting with quantification normalized to total NFKB1

  • Flow cytometry with lymphocyte subset markers to identify cell-specific defects

• Ex vivo stimulation assays: Isolate B and T cells from patients and healthy donors, then assess:

  • Phosphorylation kinetics following stimulation with activators like carboxyfluorescein succinimidyl ester (CFSE)

  • Correlation between phosphorylation defects and functional outcomes (proliferation, survival)

• Genetic variant functional characterization: For novel NFKB1 variants:

  • Create cellular models expressing patient-derived variants

  • Assess how mutations affect Ser893 phosphorylation dynamics

  • Correlate phosphorylation defects with cellular phenotypes observed in patients

• Longitudinal analysis in disease progression: CVID associated with NFKB1 mutations shows a temporally progressive defect in immunoglobulin-producing B cells . Studying phosphorylation status longitudinally could provide insights into disease progression mechanisms.

• Therapy response monitoring: Use the antibody to monitor phosphorylation status in response to therapeutic interventions, potentially serving as a biomarker for treatment efficacy.

This research approach could elucidate whether altered phosphorylation at Ser893 contributes to the pathogenesis of NFKB1-associated immunodeficiency or represents a consequence of other primary defects in NF-κB signaling.

What methodological considerations are important when using NFKB1 (Ab-893) Antibody in apoptosis resistance studies?

When investigating apoptosis resistance in cancer (particularly lymphomas) using NFKB1 (Ab-893) Antibody, researchers should consider these methodological approaches:

• Experimental design for pathway-specific analysis:

  • Use complementary methods to modulate NFKB1 activity:

    • siRNA targeting p105/p50 (for canonical pathway)

    • Adenovirus expressing dominant-negative IκBα (Adv-IκB-dn)

    • Pharmacological inhibitors targeting IKK activity or IκB degradation

  • Monitor effects on both phosphorylation status and downstream events

• Apoptosis induction protocol optimization:

  • Test multiple apoptotic stimuli targeting different pathways:

    • Extrinsic pathway: TNF (10 ng/ml) or TRAIL (100 ng/ml) with cycloheximide (10 μg/ml)

    • Intrinsic pathway: Etoposide (150 nM) or γ-irradiation (60 Gy)

  • Measure apoptosis using flow cytometry (Annexin V/PI staining) 24 hours post-treatment

• Downstream target analysis:

  • Examine correlation between NFKB1 Ser893 phosphorylation and expression of anti-apoptotic proteins:

    • Bcl-xL (primarily regulated by canonical pathway)

    • FLIP, XIAP, and CIAP (regulated by both pathways with stronger non-canonical involvement)

  • Use Western blotting or qPCR to quantify expression levels of these targets

• Functional validation:

  • Combine phosphorylation analysis with NF-κB activity assays using luciferase reporter plasmids (e.g., pGL2-NF-κB-Luc)

  • A 60% inhibition of NF-κB activity typically correlates with enhanced sensitivity to apoptosis inducers (1.5-2 fold increase)

• Cell model selection:

  • Include both constitutively NF-κB-active lymphoma cell lines and inducible models

  • Consider genetic background effects on pathway activation and apoptotic responses

These methodological considerations will help establish the relationship between NFKB1 phosphorylation at Ser893, pathway activation status, and resistance to apoptosis in cancer research contexts.

How can phospho-specific NFKB1 antibodies help distinguish between canonical and non-canonical NF-κB pathway activation?

The NF-κB signaling system consists of two major pathways—canonical and non-canonical—with distinct regulatory mechanisms and biological functions. Phospho-specific NFKB1 antibodies, including the NFKB1 (Ab-893) Antibody, can be strategically employed to distinguish between these pathways:

• Pathway-specific phosphorylation signature analysis:

  • Canonical pathway: Monitor phosphorylation at Ser893 of NFKB1/p105 alongside other canonical markers (phospho-IκBα, phospho-p65)

  • Non-canonical pathway: Compare with phosphorylation of NFKB2/p100 markers

  • Create a phosphorylation profile that distinguishes between pathway activation states

• Kinetic analysis:

  • Canonical pathway: Typically exhibits rapid activation (minutes to hours)

  • Non-canonical pathway: Shows delayed and sustained activation (hours to days)

  • Monitor Ser893 phosphorylation at multiple timepoints after stimulation with pathway-specific activators:

    • Canonical activators: TNFα, IL-1

    • Non-canonical activators: BAFF, lymphotoxin-β receptor ligands

• Subcellular localization studies:

  • Combine phospho-detection with cellular fractionation

  • Track the movement of phosphorylated NFKB1 between cytoplasmic and nuclear compartments

  • Use immunofluorescence to visualize translocation patterns characteristic of each pathway

• Downstream target correlation:

  • Research has shown distinct anti-apoptotic gene expression profiles:

    • Canonical pathway: Primarily associated with Bcl-xL overexpression

    • Non-canonical pathway: Broader profile including Bcl-xL, XIAP, CIAP, and FLIP

  • Correlate phosphorylation status with target gene expression to identify pathway-specific signatures

• Pathway inhibition experiments:

  • Apply selective inhibitors of each pathway:

    • Canonical: IKKβ inhibitors or dominant-negative IκBα

    • Non-canonical: NIK inhibitors

  • Monitor effects on Ser893 phosphorylation status

This multifaceted approach allows researchers to distinguish between the two NF-κB pathways and understand their relative contributions to various biological processes and disease states.

What technical considerations are important for validating NFKB1 (Ab-893) Antibody specificity?

Rigorous validation of NFKB1 (Ab-893) Antibody specificity is critical for generating reliable research data. The following technical considerations should be implemented:

• Phospho-peptide competition controls:

  • Pre-incubate the antibody with the phosphorylated peptide used as the immunogen

  • Compare results with and without blocking peptide in Western blots or IHC

  • Specific signals should be substantially reduced or eliminated when blocked with the phospho-peptide

  • Example: "The lane on the left is blocked with the phospho peptide" in Western blot validation

• Phosphatase treatment controls:

  • Treat sample aliquots with lambda phosphatase to remove phosphate groups

  • Compare detection between phosphatase-treated and untreated samples

  • Signal should be absent or dramatically reduced in phosphatase-treated samples

• Stimulation-dependent phosphorylation:

  • Compare unstimulated cells with those treated with known NF-κB pathway activators

  • Document increased phosphorylation following appropriate stimulation

  • Confirm signal reduction after pathway inhibition

• Cross-reactivity assessment:

  • Test against closely related phosphorylation sites on other proteins

  • Consider potential reactivity with similar motifs on unrelated proteins

  • Use lysates from cells with NFKB1 knockdown or knockout as negative controls

• Validation across multiple applications:

  • Confirm specificity in different techniques (WB, IHC, IF)

  • Document consistent results across various cell types and tissues

  • Compare results between different lots of the antibody

• Purification method confirmation:

  • Verify antibody purification via "sequential chromatography on phospho- and non-phospho-peptide affinity columns"

  • This increases specificity for the phosphorylated form of the epitope

Manufacturers typically validate their antibodies using some of these approaches, as evidenced by statements like: "The picture on the right is blocked with the phospho peptide" in immunohistochemistry validation images . Researchers should perform their own validation in their specific experimental systems for maximum confidence in results.

What are the optimal storage conditions and handling protocols for NFKB1 (Ab-893) Antibody?

Proper storage and handling of NFKB1 (Ab-893) Antibody is essential for maintaining its activity and specificity. Based on manufacturer recommendations:

Storage formulation:

• Typically supplied at 1.0 mg/mL concentration

• In phosphate buffered saline (without Mg²⁺ and Ca²⁺), pH 7.4

• Contains 150 mM NaCl, 0.02% sodium azide, and 50% glycerol

Critical handling guidelines:

• Aliquoting protocol:

  • Divide into small single-use aliquots before freezing

  • Use sterile tubes and sterile technique during aliquoting

  • Quick-freeze aliquots and store at -20°C

• Freeze-thaw management:

  • Avoid repeated freeze-thaw cycles which significantly reduce antibody activity

  • Thaw aliquots at room temperature or 4°C, never at high temperatures

  • Mix gently by flicking or mild vortexing after thawing

• Working dilution preparation:

  • Prepare fresh working dilutions on the day of experiment

  • Use appropriate diluent (typically PBS with 0.1-1% BSA)

  • Return stock to 4°C immediately after use

• Safety considerations:

  • Contains sodium azide (0.02%) which is toxic

  • Avoid contact with acids which can generate toxic gas

  • Follow proper disposal regulations for antibody solutions

• Quality control:

  • Check for visible precipitates before use (indicates potential denaturation)

  • Perform validation tests on new lots before critical experiments

  • Monitor expiration dates (typically 12 months from date of receipt)

Following these storage and handling protocols will help maximize antibody performance and experimental reproducibility.

How can multiplexed immunoassays be optimized when incorporating NFKB1 (Ab-893) Antibody?

Optimizing multiplexed immunoassays with NFKB1 (Ab-893) Antibody requires careful planning and technical considerations:

• Antibody panel design:

  • Select compatible antibodies based on host species to avoid cross-reactivity

  • For phospho-NFKB1 co-detection with other rabbit antibodies, consider:

    • Sequential staining with stripping between rounds

    • Tyramide signal amplification systems for spectral separation

    • Directly conjugated primary antibodies to eliminate secondary antibody cross-reactivity

• Validation for multiplex compatibility:

  • Test NFKB1 (Ab-893) Antibody performance in single-marker assays first

  • Systematically add additional markers while monitoring signal quality

  • Compare results with single-marker controls to ensure consistent detection

• Epitope retrieval optimization:

  • Phospho-epitopes often require specific retrieval conditions

  • Test multiple retrieval protocols to find optimal conditions for phospho-Ser893 detection

  • Prioritize phospho-epitope retrieval if trade-offs are necessary

• Signal balancing strategies:

  • Adjust antibody concentrations individually in the multiplex setting

  • Consider signal amplification specifically for phospho-epitopes

  • Use brightest fluorophores or detection systems for least abundant targets

• Control implementation:

  • Include phosphatase-treated controls to confirm specificity

  • Use stimulated samples (e.g., TNFα-treated) as positive controls

  • Incorporate single-color controls for spectral compensation

• Experimental protocol for NF-κB pathway investigation:

  • For phospho-flow cytometry, optimal cell preparation includes:

    • Immediate fixation after stimulation to preserve phosphorylation state

    • Methanol permeabilization for improved nuclear phospho-epitope access

  • For multiplexed IF/IHC:

    • Consider tyramide signal amplification for enhanced sensitivity

    • Implement careful blocking to reduce background

• Data analysis considerations:

  • Implement automated image analysis algorithms for objective quantification

  • Consider spatial relationships between phospho-NFKB1 and other markers

  • Use appropriate statistical methods for multiparameter data

These optimization strategies will improve the reliability and interpretability of multiplexed assays incorporating NFKB1 (Ab-893) Antibody, enabling more comprehensive analysis of NF-κB signaling in complex biological systems.

How can NFKB1 (Ab-893) Antibody be used to investigate cross-talk between NF-κB and other signaling pathways?

The NF-κB pathway interacts with numerous other signaling networks to coordinate cellular responses. NFKB1 (Ab-893) Antibody can be employed in several methodological approaches to investigate these cross-talk mechanisms:

• Multi-pathway phosphorylation profiling:

  • Perform simultaneous detection of phospho-NFKB1 (Ser893) alongside key phosphorylation sites in other pathways:

    • MAPK pathway: phospho-ERK1/2, phospho-p38, phospho-JNK

    • JAK/STAT pathway: phospho-STAT1, phospho-STAT3

    • PI3K/Akt pathway: phospho-Akt, phospho-mTOR

  • Implement through multiplexed Western blotting or phospho-flow cytometry

  • Analyze temporal relationships between pathway activations

• Pathway perturbation studies:

  • Apply specific inhibitors targeting distinct pathways:

    • IKK inhibitors for NF-κB pathway

    • MEK inhibitors for MAPK pathway

    • JAK inhibitors for STAT pathway

  • Monitor effects on NFKB1 Ser893 phosphorylation under basal and stimulated conditions

  • Document reciprocal relationships between pathways

• Stimulation integration analysis:

  • Apply combinatorial stimulation protocols:

    • TNFα (NF-κB activator, 10 ng/ml)

    • Growth factors (RTK pathway activators)

    • Cytokines (JAK/STAT activators)

  • Measure NFKB1 phosphorylation responses to detect synergy, antagonism, or pathway prioritization

  • Correlate phosphorylation patterns with functional outcomes

• Target gene expression correlation:

  • Monitor expression of genes regulated by multiple pathways

  • Compare gene expression profiles after pathway-specific interventions

  • Use reporter systems with pathway-specific response elements alongside phosphorylation analysis

  • Example: NF-κB-Luc reporter system as used in published research

• Genetic modulation approaches:

  • Use siRNA knockdown of pathway components (as demonstrated with p105 siRNA)

  • Employ dominant-negative constructs (e.g., Adv-IκB-dn for NF-κB inhibition)

  • Assess impact on cross-pathway signaling

• Clinical sample analysis:

  • Apply these methods to patient samples with immune disorders or cancers

  • Identify disease-specific alterations in pathway cross-talk

  • Correlate with clinical phenotypes and treatment responses

This methodological framework enables detailed investigation of how the NF-κB pathway integrates with other signaling networks in physiological and pathological contexts, potentially identifying new therapeutic targets at pathway intersection points.

What quantification methods are recommended for accurate assessment of NFKB1 phosphorylation using the Ab-893 antibody?

Accurate quantification of NFKB1 phosphorylation requires appropriate methodological approaches depending on the experimental context. The following methods are recommended when using NFKB1 (Ab-893) Antibody:

• Western blot densitometry:

  • Normalize phospho-NFKB1 signal to total NFKB1 protein level

  • Include multiple exposure times to ensure linearity of signal

  • Use housekeeping proteins (β-actin, GAPDH) as loading controls

  • Implement software analysis with background subtraction

  • Recommended dilution range: 1:500-1:2000

• Quantitative immunohistochemistry:

  • Use digital image analysis software for objective quantification

  • Measure parameters such as:

    • Staining intensity (using standardized scales)

    • Percent positive cells

    • Nuclear/cytoplasmic ratio (for translocation assessment)

  • Include calibration standards on each slide

  • Recommended dilution range: 1:50-1:300

• Flow cytometry quantification:

  • Measure mean fluorescence intensity (MFI) of phospho-signal

  • Use isotype controls and fluorescence-minus-one (FMO) controls

  • Calculate phosphorylation index: (MFI stimulated)/(MFI unstimulated)

  • Combine with cell type markers for heterogeneous samples

  • Recommended dilution around 1:100-1:200 (similar to IF applications)

• ELISA-based quantification:

  • Develop sandwich immunoassays with capture antibody against total NFKB1

  • Use NFKB1 (Ab-893) as detection antibody

  • Generate standard curves with recombinant phospho-proteins

  • Recommended dilution approximately 1:20000

• Internal controls and normalization strategies:

  • Positive controls: TNFα-stimulated cells (10 ng/ml)

  • Negative controls: Phosphatase-treated samples

  • Standardization: Include common reference samples across experiments

  • Timing considerations: Document ischemia time for clinical samples

• Reporting standards for reproducibility:

  • Document antibody source, catalog number, and lot

  • Report exact dilution used and incubation conditions

  • Provide detailed image acquisition parameters

  • Include all control data alongside experimental results

These quantification approaches, when carefully implemented and reported, enable reliable assessment of NFKB1 phosphorylation at Ser893 across different experimental systems and sample types.