NUP84 Antibody

What epitopes of NUP84 are most suitable for antibody production?

Several regions of NUP84 have proven successful for generating specific antibodies. The C-terminal domain has been effectively targeted using synthetic peptides, as demonstrated by the successful development of antibodies against the last 11 residues (QINDIRNHVNF) of the COOH terminus . This approach is particularly effective as the C-terminal region is typically well-exposed in the native protein.

The NH2-terminal region, which contains the site of interaction with CAN/Nup214, represents another functionally relevant epitope target. For structural studies, the coiled-coil domain in the COOH-terminal region may be targeted, as this domain is required for association with the cytoplasmic face of the nuclear pore complex .

When developing species-specific antibodies, researchers should target regions with low sequence conservation between yeast and mammalian NUP84. For comprehensive studies, using antibodies against multiple distinct epitopes provides validation and ensures detection across various experimental conditions.

How do monoclonal and polyclonal NUP84 antibodies compare in research applications?

Both antibody types offer distinct advantages for NUP84 research:

The QE5 monoclonal antibody has been successfully used in immunoadsorption experiments to isolate NUP84 and associated proteins from rat liver nuclear envelope extracts . For structural studies of the Nup84 complex, nanobodies (VHH-SAN4, 5, 8, and 9) selected by phage display have proven valuable .

What validation steps are essential before using a new NUP84 antibody?

Rigorous validation is crucial for ensuring reliable results with NUP84 antibodies:

• Western blot analysis should show a single band at the expected molecular weight (~84 kDa).

• Peptide competition assays using the immunizing peptide (such as the C-terminal QINDIRNHVNF sequence) should abolish the signal .

• Immunofluorescence microscopy should reveal the characteristic nuclear rim staining pattern, with enrichment at the nuclear pore complexes.

• Knockout/knockdown controls, comparing wild-type versus NUP84-depleted samples, provide definitive validation of specificity.

• For structural studies, correlation with electron microscopy data on the Y-shaped, triskelion-like morphology (25 nm in diameter) of the Nup84 complex should be performed .

• Cross-reactivity testing against other nucleoporins, particularly those with similar molecular weights, ensures specificity.

• Mass spectrometry identification following immunoprecipitation can confirm both antibody specificity and detection of known interaction partners such as CAN/Nup214 .

What are the optimal conditions for NUP84 antibody use in immunoprecipitation experiments?

For successful immunoprecipitation of NUP84 and associated complexes:

• Cell/tissue preparation: Nuclear envelope isolation significantly improves yield for NUP84 studies. For example, from rat liver tissue, nuclear envelopes can be prepared after DNase and RNase digestion following established protocols .

• Lysis buffer composition: 50 mM triethanolamine (pH 7.4), 500 mM NaCl, 0.5% Triton X-100, 1 mM DTT, and protease inhibitors effectively solubilize NUP84 while preserving interactions .

• Antibody coupling: Covalently coupling NUP84 antibodies to protein G-Sepharose using dimethylpimelimidate improves consistency and reduces background. The QE5 affinity matrix prepared this way has successfully isolated NUP84 from nuclear envelope extracts .

• Washing conditions: Multiple washes with the extraction buffer remove non-specific interactions while preserving the NUP84 complex integrity.

• Elution strategies: For protein identification, SDS-PAGE sample buffer elution works effectively. For maintaining native complexes, consider peptide competition elution .

Using this approach, researchers have successfully recovered 4–10 μg of Nup84 protein (approximately 50–100 pmol) from about 100 g of liver tissue, sufficient for downstream analyses including mass spectrometry .

How should fixation and immunostaining protocols be optimized for NUP84 detection?

Optimal detection of NUP84 in immunofluorescence applications requires careful attention to fixation and permeabilization:

What are the challenges in generating species-specific NUP84 antibodies and how can they be addressed?

Developing species-specific NUP84 antibodies presents several challenges:

• Evolutionary conservation: Core structural domains of NUP84 are conserved across species, making it difficult to generate truly species-specific antibodies. The search results mention approaches for cloning the human homologue of Nup84 using a lambda gt10 human T cell library screened with a rat cDNA fragment, indicating significant sequence homology .

• Strategies for species-specificity:

  • Target divergent regions by comprehensive sequence alignment

  • Use species-specific peptides for immunization

  • Implement rigorous screening against lysates from multiple species

  • Consider epitope mapping to identify uniquely accessible regions

• Validation approaches:

  • Western blotting across multiple species lysates

  • Immunofluorescence pattern comparison in different cell types

  • Testing against knockout/knockdown controls in the target species

  • Peptide competition with species-specific and cross-reactive peptides

• Application-specific considerations:

  • For evolutionary studies, antibodies against conserved domains may be preferable

  • For model organism research, highly specific antibodies are essential

  • For structural studies, epitope accessibility may vary between species

• Production recommendations:

  • Express species-specific fragments in heterologous systems

  • Use affinity purification against the immunizing peptide

  • Screen for clones that distinguish between closely related species

  • Validate across multiple experimental conditions

How can NUP84 antibodies be used to study DNA damage response mechanisms?

NUP84 plays significant roles in DNA damage response pathways, making antibodies against it valuable tools in this research area:

• NUP84 in DNA repair: The search results indicate that nup84Δ cells are defective in Nucleotide Excision Repair (NER) and fail to repair UV-induced cyclobutane pyrimidine dimers (CPDs) independently of transcription . Antibodies can help visualize and characterize this involvement.

• Experimental approaches:

  • Combined immunofluorescence with DNA damage markers (γH2AX) and repair factors

  • Chromatin immunoprecipitation before and after DNA damage induction

  • Analysis of NUP84 redistribution following genotoxic stress

  • Co-immunoprecipitation with repair pathway components

• Replication stress studies: NUP84 antibodies can be used to investigate its role during replication through damaged DNA templates. The search results note that nup84Δ mutants show sensitivity to hydroxyurea (HU), suggesting involvement in replication stress responses .

• PCNA modification analysis: NUP84 antibodies can be combined with methods for analyzing PCNA ubiquitylation and sumoylation, as described in the search results, where cells carrying plasmid YEp195-CUP-HisSmt3 or YEp195-CUP-HisUb were analyzed following UV irradiation .

• Cell cycle-specific responses:

  • Synchronization methods combined with damage induction

  • Co-staining with cell cycle markers

  • Analysis of repair factor recruitment in different phases

• Methodological approach for studying NUP84 in CPD repair:

  • UV irradiation of cells (typically 150 J/m²)

  • T4 endonuclease V treatment to detect CPDs

  • Restriction fragment analysis to measure intact DNA

  • Calculation of CPD content using the Poisson expression, -ln(RF a/RF b)

What is the role of NUP84 in retrotransposon regulation and how can antibodies help study this function?

NUP84 has a newly discovered role in retrotransposon regulation that can be investigated using antibodies:

• The Nup84 complex specifically restricts the transcription of LTR-retrotransposons in yeast, affecting both Copia and Gypsy Ty LTR-retrotransposons throughout the S. cerevisiae genome .

• Mechanistic studies using antibodies:

  • ChIP-seq with NUP84 antibodies to identify direct associations with retrotransposon regions

  • Co-immunoprecipitation with silencing factors to identify interaction partners

  • Immunofluorescence co-localization with retrotransposon transcription sites

  • Analysis of NUP84 distribution relative to active vs. silenced retrotransposons

• SUMO pathway connections: The search results indicate that the Nup84 complex restricts Ty1 transcription through the tethering of the SUMO-deconjugating enzyme Ulp1 to NPCs . Antibodies can help:

  • Visualize co-localization of Ulp1 and NUP84

  • Analyze SUMO modifications in wild-type vs. nup84Δ cells

  • Study the dynamics of this interaction during retrotransposon activation

• Transcriptional control analysis:

  • RNA FISH for retrotransposon transcripts combined with NUP84 immunostaining

  • Nascent RNA detection at nuclear pores

  • Quantification of transcription rates in the presence/absence of NUP84

• cDNA accumulation studies: The search results note that modest accumulation of Ty1 RNAs caused by Nup84 complex loss-of-function triggers a significant increase in Ty1 cDNA levels, resulting in massive retrotransposition . Antibodies can help:

  • Track the cellular localization of reverse transcription events

  • Analyze the relationship between NPC organization and cDNA production

  • Study integration site preferences relative to NPC positions

How can NUP84 antibodies contribute to understanding nuclear pore complex assembly?

The structural organization and assembly of nuclear pore complexes can be effectively studied using NUP84 antibodies:

• The Nup84p complex is a core building block of the NPC with a distinctive Y-shaped, triskelion-like morphology measuring 25 nm in diameter . Antibodies can help:

  • Visualize intermediate assembly steps

  • Track incorporation of NUP84 into forming NPCs

  • Identify assembly defects in mutant conditions

• Composition analysis: The Nup84p complex consists of five nucleoporins (Nup84p, Nup85p, Nup120p, Nup145p-C, and Seh1p) and Sec13p, a shared component with the COPII coat complex . Antibodies against NUP84 can:

  • Co-immunoprecipitate interacting subunits to study complex formation

  • Analyze stoichiometry in different cellular conditions

  • Identify novel interaction partners

• Critical assembly components: According to the search results, Nup85p, Nup120p, and Nup145p-C are essential for the assembly of the complex . Antibody approaches can:

  • Compare wild-type vs. mutant assembly states

  • Track assembly intermediates in various conditions

  • Analyze co-dependent assembly relationships

• Quantitative structural analysis:

  • Immunogold electron microscopy to precisely localize NUP84 within the complex

  • Super-resolution microscopy to study spatial relationships between components

  • Single-particle analysis of immunopurified complexes

• Assembly dynamics during the cell cycle:

  • Synchronization methods combined with time-course immunofluorescence

  • Analysis of NUP84 redistribution during mitosis and nuclear envelope reformation

  • Co-staining with cell cycle markers to track assembly timing

What are common issues when using NUP84 antibodies and how can they be resolved?

Researchers commonly encounter several challenges when working with NUP84 antibodies:

• Weak or no signal in Western blots:

  • Issue: Insufficient protein or epitope masking

  • Solutions: Increase protein loading (30-50 μg); try different sample preparation methods; enrich for nuclear envelope fraction; increase antibody concentration or incubation time

• Multiple bands or non-specific binding:

  • Issue: Antibody cross-reactivity or protein degradation

  • Solutions: Include protease inhibitors in sample preparation; optimize antibody dilution; increase washing stringency; pre-adsorb antibody against related nucleoporins

• High background in immunofluorescence:

  • Issue: Non-specific binding or inadequate blocking

  • Solutions: Increase blocking time; use different blocking agents (BSA vs. serum); add extra washing steps; consider alternative fixation methods that better preserve NPC structure

• Poor immunoprecipitation efficiency:

  • Issue: Inadequate antibody binding or harsh extraction conditions

  • Solutions: Follow successful protocols from the literature, such as using 50 mM triethanolamine (pH 7.4), 500 mM NaCl, 0.5% Triton X-100, 1 mM DTT, and protease inhibitors for extraction ; consider antibody coupling to solid support

• Inconsistent results between experiments:

  • Issue: Batch-to-batch antibody variation or sample preparation differences

  • Solutions: Purchase larger antibody lots; validate each new lot; establish standard operating procedures; include consistent positive controls

What controls are essential when using NUP84 antibodies?

Proper controls are critical for reliable interpretation of NUP84 antibody experiments:

• Negative controls:

  • Isotype control antibodies (same species and isotype as NUP84 antibody)

  • Secondary antibody only (no primary antibody)

  • NUP84 knockout/knockdown samples when available

  • Pre-immune serum for polyclonal antibodies

• Positive controls:

  • Known NUP84-expressing tissues/cell lines

  • Recombinant NUP84 protein

  • Previously validated samples with established staining patterns

• Specificity controls:

  • Peptide competition assays using the immunizing peptide (e.g., QINDIRNHVNF)

  • Multiple antibodies against different NUP84 epitopes

  • Correlation with other nuclear pore markers

• Application-specific controls:

  • For Western blotting: Molecular weight markers; loading controls (nuclear lamins)

  • For immunofluorescence: Co-staining with known NPC markers; DAPI nuclear counterstain

  • For immunoprecipitation: Input sample; IgG control precipitation; known interaction partners (e.g., CAN/Nup214)

  • For ChIP: Input chromatin; IgG control ChIP; positive and negative control regions

• Technical validation:

  • Antibody dilution series to establish optimal concentration

  • Multiple biological replicates

  • Confirmation with orthogonal techniques

How can researchers optimize NUP84 antibody-based chromatin immunoprecipitation (ChIP) experiments?

ChIP experiments with NUP84 antibodies require special considerations due to NUP84's primary role as a structural protein:

• Experimental design considerations:

  • NUP84's association with chromatin may be indirect through other proteins

  • Consider dual crosslinking approaches for improved protein-DNA capture

  • Focus on genomic regions with established NPC associations

• Crosslinking protocol optimization:

  • Standard: 1% formaldehyde for 10 minutes at room temperature

  • Enhanced: Add protein-protein crosslinkers like DSP or EGS before formaldehyde

  • Quenching with 125 mM glycine for 5 minutes

• Chromatin preparation:

  • Sonication to generate 200-500 bp fragments

  • Verification of fragmentation by agarose gel electrophoresis

  • Pre-clearing with protein A/G beads and non-specific IgG

• Immunoprecipitation optimization:

  • Antibody amount: 3-5 μg per ChIP reaction

  • Incubation: overnight at 4°C with rotation

  • Beads: protein A/G magnetic beads for 2-3 hours

• Washing conditions:

  • Low salt wash buffer: 20 mM Tris-HCl pH 8.0, 150 mM NaCl, 2 mM EDTA, 0.1% SDS, 1% Triton X-100

  • High salt wash buffer: same as low salt but with 500 mM NaCl

  • LiCl wash buffer: 10 mM Tris-HCl pH 8.0, 250 mM LiCl, 1 mM EDTA, 1% NP-40, 1% sodium deoxycholate

  • TE buffer: 10 mM Tris-HCl pH 8.0, 1 mM EDTA

• Analysis focus:

  • Target regions involved in:

    • DNA damage response

    • Retrotransposon regulation

    • Genes affected in NUP84 mutants

  • Compare results with transcriptomic data from wild-type vs. nup84Δ cells

How can super-resolution microscopy be combined with NUP84 antibodies for structural studies?

Super-resolution microscopy offers powerful approaches for studying NUP84 at the nanoscale:

• Compatible super-resolution techniques:

  • STORM (Stochastic Optical Reconstruction Microscopy)

  • PALM (Photoactivated Localization Microscopy)

  • STED (Stimulated Emission Depletion)

  • Expansion microscopy

• Antibody considerations for super-resolution:

  • Directly labeled primary antibodies reduce localization error

  • Fab fragments or nanobodies provide smaller label size

  • Bright, photostable fluorophores with appropriate photoswitching properties

  • Careful titration to achieve optimal labeling density

• Sample preparation optimization:

  • Thin sectioning or flat cell areas improve axial resolution

  • Multi-color labeling with other NPC components enables structural mapping

  • Careful fixation to preserve nanoscale structure while maintaining epitope accessibility

• Research applications:

  • Precise localization of NUP84 within the NPC structure

  • Analysis of the Y-shaped, triskelion-like morphology of the Nup84 complex

  • Mapping interactions with other nucleoporins and transport factors

  • Tracking structural changes during cell cycle or stress conditions

• Validation approaches:

  • Correlation with electron microscopy data

  • Comparison with crystal structures where available

  • Consistency across different super-resolution techniques

  • Biological validation through functional mutants

What future directions are emerging for NUP84 antibody applications in disease research?

NUP84 antibodies are increasingly valuable in disease-related research:

• Cancer biology applications:

  • Analysis of NUP84 expression and localization in different cancer types

  • Investigation of nuclear pore alterations during malignant transformation

  • Studies of nucleocytoplasmic transport disruption in cancer cells

  • Correlation with genomic instability phenotypes

• Neurodegenerative disease connections:

  • Examination of NPC structure in aging and neurodegeneration

  • Studies of nucleocytoplasmic transport defects in neurodegenerative conditions

  • Investigation of nuclear envelope integrity in disease models

  • Analysis of protein aggregation at the nuclear periphery

• Viral infection research:

  • Studies of viral component interactions with the NPC

  • Investigation of NPC alterations during viral infection

  • Analysis of viral evasion of cellular defense mechanisms

  • Development of therapeutic strategies targeting NPC-viral interactions

• Genomic instability disorders:

  • The search results indicate nup84Δ cells show sensitivity to genotoxic agents and undergo genomic instability

  • Antibodies can help characterize:

    • DNA damage signaling at nuclear pores

    • Repair pathway choice mechanisms

    • Chromosome segregation defects

    • Telomere maintenance disruptions

• Methodological innovations:

  • Patient-derived cell studies with quantitative imaging

  • Tissue microarray analysis in disease progression

  • Combination with single-cell approaches for heterogeneity assessment

  • Therapeutic target identification and validation