rpl-35 Antibody

What is RPL35 and why is it important in cellular function?

RPL35 (Ribosomal Protein L35) is a component of the large ribosomal subunit (60S) that contributes to ribosome formation and stability. The ribosome is a large ribonucleoprotein complex responsible for protein synthesis within cells . RPL35 is also known as large ribosomal subunit protein uL29 or 60S ribosomal protein L35 . The function of RPL35 is critical for maintaining the efficiency and accuracy of protein synthesis, which directly influences cell growth and proliferation . Understanding RPL35's role provides insights into fundamental cellular processes and potential implications in disease states where protein synthesis is dysregulated.

What applications are RPL35 antibodies suitable for?

RPL35 antibodies have been validated for multiple experimental applications across different research platforms:

Different antibodies may have specific optimal applications, so selecting the appropriate antibody for your experimental design is essential for generating reliable results .

What is the molecular weight of RPL35 and how does this affect antibody detection?

RPL35 has a calculated molecular weight of approximately 15 kDa as observed in Western blot analyses . This relatively small size can present certain technical challenges during protein extraction and detection. When performing Western blots for RPL35, researchers should optimize gel percentage (typically 12-15% acrylamide) to properly resolve proteins in this size range. Additionally, transfer conditions may need adjustment to ensure efficient transfer of small proteins to the membrane. Most validated RPL35 antibodies detect a band at the expected 15 kDa position in Western blots from various cell lines including MCF7, HeLa, and Jurkat cells , confirming the specificity of these antibodies for the target protein.

Which species reactivity has been confirmed for RPL35 antibodies?

The available research data indicates that most RPL35 antibodies have been validated for reactivity with:

How can RPL35 antibodies be validated for specificity in complex experimental systems?

Validating RPL35 antibody specificity in complex experimental systems requires a multi-faceted approach:

• Knockout/Knockdown Controls: Generate RPL35 knockout or knockdown cells using CRISPR-Cas9 or RNAi technology. The disappearance of the signal in Western blot or immunostaining confirms antibody specificity.

• Blocking Peptide Competition: Pre-incubate the antibody with the immunizing peptide before application to samples. Signal reduction demonstrates specific binding to the target epitope.

• Multiple Antibody Validation: Use different antibodies targeting distinct RPL35 epitopes to confirm consistent localization and expression patterns .

• Cross-Application Verification: Confirm RPL35 detection across multiple techniques (e.g., if detected by WB, verify with IHC or IF) .

• Mass Spectrometry Confirmation: For definitive validation, immunoprecipitate RPL35 using the antibody and confirm the pulled-down protein's identity via mass spectrometry.

This comprehensive validation approach ensures that observed signals are truly representative of RPL35 presence and not due to non-specific interactions or cross-reactivity.

What are the optimal subcellular fractionation protocols for studying RPL35 distribution?

Given RPL35's role in ribosome biology, optimal subcellular fractionation for studying its distribution should focus on ribosomal compartments:

• Differential Centrifugation Protocol:

  • Homogenize cells in isotonic buffer (250mM sucrose, 10mM HEPES pH 7.4, 1mM EDTA) with protease inhibitors

  • Perform sequential centrifugation steps:

    • 1,000g (10 min): Nucleus and debris

    • 10,000g (15 min): Mitochondria and large organelles

    • 100,000g (60 min): Microsomes and ribosomes

    • Supernatant: Cytosolic fraction

• Polysome Profiling:

  • Treat cells with cycloheximide (100 μg/mL, 10 min) to freeze ribosomes on mRNA

  • Lyse cells in polysome buffer (10mM HEPES pH 7.4, 100mM KCl, 5mM MgCl₂, 1% Triton X-100)

  • Load lysate onto 10-50% sucrose gradient

  • Ultracentrifuge at 36,000 rpm (2.5 hours, 4°C)

  • Collect fractions and analyze by Western blot using RPL35 antibody

• Nucleolar Isolation:

  • Since ribosome biogenesis occurs in nucleoli, isolate nucleoli using sonication and sucrose cushion centrifugation

  • Compare RPL35 distribution between nucleolar, nucleoplasmic, and cytoplasmic fractions

Western blot analysis with RPL35 antibodies shows cytoplasmic positivity in glandular cells , consistent with its role in ribosomes, which are primarily cytoplasmic but can also be found in the nucleus during biogenesis.

How can RPL35 antibodies be utilized in studies of ribosome biogenesis and stress responses?

RPL35 antibodies can serve as powerful tools for investigating ribosome biogenesis and cellular stress responses:

• Ribosome Assembly Analysis:

  • Pulse-chase labeling of newly synthesized ribosomal components

  • Immunoprecipitation with RPL35 antibodies at different time points

  • Analysis of co-precipitating factors to map temporal assembly patterns

• Stress Response Monitoring:

  • Expose cells to various stressors (oxidative stress, nutrient deprivation, heat shock)

  • Perform subcellular fractionation followed by Western blot with RPL35 antibody

  • Track changes in RPL35 localization and incorporation into mature ribosomes

  • Correlate with global protein synthesis rates measured by puromycin incorporation

• Co-localization Studies:

  • Use dual immunofluorescence with RPL35 antibodies and markers of stress granules or P-bodies

  • Analyze redistribution of RPL35 during integrated stress response activation

• Ribosome Heterogeneity Assessment:

  • Immunoprecipitate RPL35-containing complexes under different conditions

  • Perform mass spectrometry to identify condition-specific ribosome compositions

  • Validate findings with targeted Western blots using the RPL35 antibody

These approaches leverage the specificity of RPL35 antibodies to illuminate complex cellular processes involving ribosome dynamics and stress adaptation mechanisms.

What are the optimal dilutions and conditions for using RPL35 antibodies in different applications?

Based on validated protocols, the following dilution ranges and conditions are recommended for RPL35 antibodies:

These ranges should be considered starting points, and researchers should perform titration experiments to determine the optimal concentration for their specific experimental system. Antibody performance can vary depending on the sample type, preparation method, and detection system employed .

What controls should be included when using RPL35 antibodies in experimental settings?

Robust experimental design with RPL35 antibodies requires several critical controls:

• Positive Controls:

  • Include samples known to express RPL35 (e.g., HeLa cells, MCF7 cells, mouse heart tissue)

  • Use recombinant RPL35 protein when available

• Negative Controls:

  • Primary antibody omission control

  • Non-specific IgG from the same species as the primary antibody

  • RPL35 knockdown/knockout samples (ideal but may not be viable long-term due to essential nature of ribosomal proteins)

• Peptide Competition:

  • Pre-incubate antibody with immunizing peptide to confirm specificity

• Loading/Staining Controls:

  • For Western blots: β-actin, GAPDH, or total protein stain (Ponceau S)

  • For IHC/IF: Nuclear counterstain (DAPI, Hoechst)

• Cross-Validation Controls:

  • Use multiple antibodies targeting different epitopes of RPL35

  • Validate findings across multiple detection methods

Implementing these controls ensures reliable interpretation of results and helps distinguish between specific RPL35 signals and experimental artifacts or background .

How do different sample preparation methods affect RPL35 antibody performance?

Sample preparation significantly impacts RPL35 antibody performance across different applications:

• Western Blot Sample Preparation:

  • Optimal lysis buffers: RIPA buffer supplemented with protease inhibitors

  • Sonication helps disrupt ribosomal complexes, improving RPL35 detection

  • Heating samples at 95°C for 5 minutes in Laemmli buffer denatures protein complexes

  • Fresh samples typically yield better results than frozen/thawed samples

• Immunohistochemistry Preparation:

  • Fixation: 10% neutral buffered formalin (24-48 hours) preserves RPL35 antigenicity

  • Paraffin embedding must be followed by appropriate antigen retrieval

  • Antigen retrieval methods: TE buffer pH 9.0 shows superior results, though citrate buffer pH 6.0 is also effective

  • Optimal section thickness: 4-5 μm

• Immunofluorescence Sample Preparation:

  • Fixation: 4% paraformaldehyde (15 minutes at room temperature)

  • Permeabilization: 0.1-0.5% Triton X-100 (10 minutes)

  • Blocking: 1-5% BSA or normal serum (1 hour)

  • Extended primary antibody incubation (overnight at 4°C) improves signal-to-noise ratio

Different cell lines may require optimization of these parameters to achieve optimal results. For example, HeLa cells have been consistently used for validating RPL35 antibodies in IF applications , suggesting they express detectable levels of the protein and represent a good positive control.

What are common issues with Western blotting for RPL35 and how can they be resolved?

When performing Western blots for RPL35, researchers may encounter several challenges:

• No Signal or Weak Signal:

  • Increase antibody concentration within recommended range (1:200-1:1000)

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

  • Optimize protein loading (15-30 μg total protein)

  • Use enhanced chemiluminescence (ECL) substrate with higher sensitivity

  • Confirm sample preparation preserves protein integrity (add fresh protease inhibitors)

• Multiple Bands or Unexpected Molecular Weight:

  • Verify gel percentage (12-15% recommended for 15 kDa proteins)

  • Use fresh samples to prevent degradation

  • Increase blocking stringency (5% milk or BSA, 1-2 hours)

  • Run known positive controls (MCF7, HeLa cells)

  • Consider post-translational modifications or isoforms if bands appear at higher molecular weights

• High Background:

  • Increase washing duration and number of washes

  • Reduce primary antibody concentration

  • Filter blocking solutions to remove particulates

  • Use highly purified secondary antibodies

  • Pre-adsorb antibodies with cell/tissue lysate from species of secondary antibody

• Inconsistent Results:

  • Standardize protein extraction and quantification methods

  • Maintain consistent transfer conditions

  • Document lot-to-lot variation in antibody performance

  • Create aliquots of antibody to avoid freeze-thaw cycles

Following these troubleshooting approaches can help resolve common Western blotting issues when detecting RPL35.

How can cross-reactivity issues with RPL35 antibodies be identified and mitigated?

Cross-reactivity can compromise experimental results. Here's how to identify and address these issues:

• Identification Methods:

  • Western blot analysis across multiple species to compare band patterns

  • Mass spectrometry analysis of immunoprecipitated proteins

  • Testing antibody on samples with known RPL35 knockdown

  • Peptide competition assays with both specific and homologous peptides

• Mitigation Strategies:

  • Select antibodies raised against unique regions of RPL35 with minimal homology to other proteins

  • Use antibodies validated specifically for your species of interest

  • Increase washing stringency in all applications

  • Perform pre-adsorption against potential cross-reactive proteins

  • Adjust antibody concentration to minimize non-specific binding while maintaining specific signal

• Sequence Homology Considerations:

  • RPL35 shares structural features with other ribosomal proteins

  • Antibodies against C-terminal regions (AA 86-115) or internal regions may have different cross-reactivity profiles

  • Consider using antibodies generated against recombinant full-length protein rather than synthetic peptides when possible

• Validation Across Applications:

  • Confirm consistent results across multiple detection methods

  • Compare patterns in Western blot, IHC, and IF to ensure consistent target recognition

Careful antibody selection and validation are essential for experiments where distinguishing RPL35 from related proteins is critical to accurate interpretation of results.

How can RPL35 antibodies be applied in studying disease mechanisms involving ribosomes?

RPL35 antibodies can provide valuable insights into disease mechanisms involving ribosomal dysfunction:

• Cancer Research Applications:

  • Compare RPL35 expression and localization in matched tumor/normal tissues using IHC

  • Correlate with patient prognosis and treatment response

  • IHC analysis has been validated in various cancer tissues, including liver, pancreas, stomach, and thyroid cancer

  • Investigate changes in ribosome composition using co-immunoprecipitation with RPL35 antibodies

• Neurodegenerative Disease Research:

  • Examine RPL35 expression in models of neurodegeneration

  • Analyze co-localization with stress granule markers

  • Study relationship between protein synthesis defects and disease progression

  • Cerebral tissue has shown cytoplasmic positivity with RPL35 antibodies

• Developmental Disorders:

  • Track RPL35 expression during embryonic development

  • Investigate effects of ribosomopathy-associated mutations on RPL35 incorporation into ribosomes

  • Study tissue-specific expression patterns using validated IHC protocols

• Cellular Stress Response:

  • Monitor RPL35 redistribution during various stress conditions

  • Analyze ribosome heterogeneity in response to environmental changes

  • Investigate selective translation mechanisms during stress

These applications leverage the specificity of RPL35 antibodies to illuminate how ribosomal changes contribute to disease pathogenesis, potentially identifying new therapeutic targets or diagnostic approaches.

What are the considerations for using RPL35 antibodies in co-immunoprecipitation experiments?

Co-immunoprecipitation (Co-IP) with RPL35 antibodies presents unique challenges and opportunities:

• Optimization Considerations:

  • Lysis buffer selection: Non-denaturing buffers that preserve protein-protein interactions

    • Recommended: 20mM Tris-HCl pH 7.5, 150mM NaCl, 1mM EDTA, 1% NP-40, protease inhibitors

    • Avoid harsh detergents like SDS that disrupt ribosomal complexes

  • Pre-clearing lysates is essential to reduce non-specific binding

  • Cross-linking antibodies to beads improves recovery and reduces antibody contamination

  • RNase treatment can distinguish RNA-dependent and direct protein interactions

• Control Experiments:

  • Non-specific IgG control from same species as RPL35 antibody

  • Input sample (5-10% of lysate used for IP)

  • Reverse Co-IP using antibodies against suspected interacting partners

  • RPL35 knockdown/knockout negative controls when feasible

• Detection Strategies:

  • Western blot for known ribosomal proteins and potential interactors

  • Mass spectrometry for unbiased identification of co-precipitated proteins

  • RNA sequencing of associated transcripts after cross-linking

• Challenges and Solutions:

  • Abundance issue: RPL35 is highly expressed, potentially leading to non-specific interactions

    • Solution: Titrate antibody and lysate concentrations

  • Complex stability: Ribosomal complexes may dissociate during purification

    • Solution: Optimize salt and detergent concentrations; consider gentle crosslinking

  • Antibody interference: Heavy chains can mask proteins of similar size

    • Solution: Use HRP-conjugated light-chain specific secondary antibodies

When properly optimized, Co-IP with RPL35 antibodies can reveal important insights into ribosome composition and extraribosomal functions of RPL35.