mrpl-35 Antibody

What is MRPL35 and why is it significant in mitochondrial research?

MRPL35 (Mitochondrial Ribosomal Protein L35) is a critical component of the mitochondrial ribosome that plays an essential role in mitochondrial protein synthesis and ribosomal assembly. It is particularly significant because it coordinates the synthesis of proteins essential for mitochondrial function. Dysregulation of MRPL35 has been implicated in various diseases, including metabolic disorders and cancer, making it an important target for therapeutic intervention studies . Research techniques targeting MRPL35 are valuable for investigating mitochondrial biology and metabolism, as well as for understanding disease pathways related to mitochondrial dysfunction.

What are the validated applications for MRPL35 antibodies in research?

MRPL35 antibodies have been validated for several laboratory applications, with the most common being Western blot (WB) analysis. According to technical documentation, these antibodies are also validated for Enzyme-Linked Immunosorbent Assay (ELISA) and Immunohistochemistry (IHC) on formalin/PFA-fixed paraffin-embedded sections . For Western blot applications, the recommended dilution ranges from 1:500-1:2000 for some antibodies (PACO07202) and 1:100-1:250 for others (PAB28123) . For immunohistochemistry, a dilution range of 1:20-1:50 has been validated with certain antibodies showing strong cytoplasmic positivity in superficial squamous epithelial cells in human esophageal tissue .

How should MRPL35 antibodies be stored and handled for optimal performance?

MRPL35 antibodies should be stored according to manufacturer specifications to maintain reactivity and specificity. Most MRPL35 antibodies are provided in liquid form in PBS containing glycerol (typically 40-50%), BSA (0.5% for some formulations), and sodium azide (0.02%) as a preservative . For short-term storage, maintaining the antibody at 4°C is generally recommended. For long-term storage, -20°C is advised. To prevent degradation from repeated freeze-thaw cycles, it is best practice to aliquot the antibody into smaller volumes before freezing . When handling these antibodies, researchers should be aware that some formulations contain sodium azide, which is a hazardous substance requiring appropriate safety precautions .

What controls should be included when using MRPL35 antibodies?

When designing experiments with MRPL35 antibodies, proper controls are essential for result validation. Positive controls should include tissues or cell lines known to express MRPL35, such as human 293 cells for Western blot analysis, which have been documented to show specific binding . RT-4, U-251 MG cell lines, human plasma, liver, and tonsil samples have also been validated as appropriate positive controls for MRPL35 detection by Western blot . For negative controls, researchers should consider using samples where MRPL35 expression has been knocked down via RNA interference techniques. Additionally, including a primary antibody omission control and an isotype control (matching the host species and isotype of the MRPL35 antibody) is recommended to assess non-specific binding.

How can researchers optimize MRPL35 detection in different subcellular fractions?

Optimizing MRPL35 detection in subcellular fractions requires careful consideration of mitochondrial isolation and protein extraction methods. Since MRPL35 is a mitochondrial ribosomal protein, enrichment of the mitochondrial fraction prior to immunoblotting can significantly improve detection sensitivity. Researchers should employ differential centrifugation techniques to isolate intact mitochondria, followed by gentle lysis conditions to preserve the integrity of mitochondrial ribosomal complexes.

For Western blot analysis, using gradient gels (10-15%) can improve resolution of MRPL35, which has a relatively small molecular weight. Based on experimental evidence, MRPL35 antibodies show strong cytoplasmic positivity in immunohistochemical staining, reflecting its mitochondrial localization . When troubleshooting weak signals, consider increasing antibody concentration, extending incubation time, or using enhanced chemiluminescence detection systems with longer exposure times.

What experimental approaches are effective for studying MRPL35 function in cancer models?

Several experimental approaches have proven effective for investigating MRPL35 function in cancer models. RNA interference techniques using lentiviral vectors expressing shRNA targeting MRPL35 have successfully demonstrated the role of MRPL35 in gastric carcinoma cell proliferation . After confirming knockdown efficiency (typically >70% by qRT-PCR and Western blotting), researchers can assess cellular phenotypes using:

• Proliferation assays: Celigo cell count assay has demonstrated that MRPL35 knockdown inhibits proliferation of gastric cancer cell lines (AGS and HGC-27) .

• Colony formation assays: These have shown reduced colony-forming ability in MRPL35-depleted cancer cells .

• Apoptosis analysis: Flow cytometry has revealed increased apoptosis in gastric cancer cells following MRPL35 knockdown .

• In vivo tumor formation: Xenograft models using BALB/c nude mice have confirmed that MRPL35 depletion inhibits tumor growth, validating in vitro findings .

For mechanistic studies, proteomic analyses like isobaric tags for relative and absolute quantification have identified downstream proteins affected by MRPL35 knockdown, including PICK1, BCL-XL, and AGR2 .

How can researchers distinguish between specific and non-specific binding when using MRPL35 antibodies?

Distinguishing between specific and non-specific binding is crucial for accurate interpretation of results with MRPL35 antibodies. Multiple validation steps should be implemented:

• Peptide competition assay: Pre-incubating the antibody with the immunizing peptide/protein should eliminate specific binding signals. The MRPL35 antibody PACO07202 uses a synthesized peptide derived from the internal region of human MRP-L35 (AA range: 80-160) as its immunogen , and PAB28123 uses a recombinant protein with the sequence LASSTYRNCVKNASLISALSTGRFSHIQTPVVSSTPRLTTSERNLTCGHTSVILNRMAPVLPSVLKLPVRSLTYF . These peptides can be synthesized for competition assays.

• MRPL35 knockdown or knockout controls: Comparing signal intensity between wild-type samples and those with reduced MRPL35 expression provides strong evidence of antibody specificity. Published research has established methods for MRPL35 knockdown using lentiviral vectors expressing shRNA .

• Cross-validation with multiple antibodies: Using different antibodies targeting distinct epitopes of MRPL35 should produce consistent patterns of expression if binding is specific.

• Size verification: The detected band in Western blot should match the expected molecular weight of MRPL35. Any additional bands should be thoroughly investigated to determine if they represent modified forms of MRPL35 or non-specific binding.

What are the implications of MRPL35 mutations for experimental design in mitochondrial function studies?

MRPL35 mutations have significant implications for experimental design in mitochondrial function studies. Research has demonstrated that mutations in the Y275 residue of MRPL35 (Y275A and Y275D) affect cytochrome c oxidase (COX) assembly . When designing experiments involving MRPL35 mutations:

• Temperature-sensitive phenotypes: MRPL35 mutants exhibit temperature-dependent defects in COX assembly. Experiments should include both permissive (standard growth temperature) and non-permissive (elevated temperature, typically 37°C) conditions to fully characterize phenotypes .

• Protein synthesis and stability analysis: Western blotting should be employed to monitor levels of mitochondrially-encoded proteins (particularly COX subunits Cox1, Cox2, and Cox3) as these are dramatically reduced in MRPL35 mutants at non-permissive temperatures .

• Functional assays: Respiratory capacity measurements should be included to assess the functional consequences of MRPL35 mutations on mitochondrial activity.

• Assembly analysis: Blue native gel electrophoresis can be used to examine the effects of MRPL35 mutations on the assembly of respiratory chain complexes.

• Genetic complementation: Including wild-type MRPL35 as a control for rescue experiments is essential for confirming that observed phenotypes are specifically due to MRPL35 mutations .

How can MRPL35 antibodies be used to investigate mitochondrial ribosome assembly?

MRPL35 antibodies can be powerful tools for investigating mitochondrial ribosome assembly through several specialized techniques:

• Immunoprecipitation (IP) followed by mass spectrometry: This approach can identify MRPL35 interaction partners during various stages of mitochondrial ribosome assembly. Crosslinking before immunoprecipitation may capture transient interactions.

• Sucrose gradient fractionation with immunoblotting: This technique allows visualization of MRPL35 distribution across different ribosomal assembly intermediates. Fractions can be collected from sucrose gradients and analyzed by Western blot using MRPL35 antibodies to track the protein's association with ribosomal subunits and assembly intermediates .

• Proximity labeling techniques: BioID or APEX2 fused to MRPL35 can identify proteins in close proximity during ribosome assembly, providing spatial and temporal information about the assembly process.

• Immunofluorescence microscopy: Co-localization studies using MRPL35 antibodies alongside markers for mitochondrial ribosomes can reveal the spatial organization of ribosome assembly within mitochondria.

When interpreting results, researchers should consider that MRPL35 plays a key role in coordinating the synthesis of the Cox1 subunit with its assembly into the cytochrome c oxidase complex , suggesting MRPL35 may have dual functions in ribosome structure and coordinating translation with respiratory chain assembly.

What techniques can resolve conflicting data regarding MRPL35 expression in different tissue types?

Resolving conflicting data regarding MRPL35 expression across different tissue types requires multi-faceted approaches:

• Multi-antibody validation: Utilize several antibodies targeting different epitopes of MRPL35 to confirm expression patterns. The two antibodies described in the search results (PACO07202 and PAB28123) could be compared for consistency in tissue staining patterns .

• Quantitative approaches: Implement absolute quantification methods such as digital PCR or selected reaction monitoring (SRM) mass spectrometry to determine precise MRPL35 expression levels across tissues.

• Single-cell analysis: Single-cell RNA sequencing or in situ hybridization can resolve cell-type specific expression that might be masked in whole-tissue analyses.

• Tissue microarrays: Systematic analysis using standardized immunohistochemistry protocols on tissue microarrays can provide comparable data across multiple tissue types. Published data shows that MRPL35 antibodies have successfully been used on tissue microarrays to evaluate expression in gastric cancer tissues compared to adjacent normal tissues .

• Correlation with mitochondrial content: Normalize MRPL35 expression to mitochondrial mass markers to account for variations in mitochondrial content between tissues, which can be a confounding factor when comparing expression levels.

• Functional validation: Perform tissue-specific knockdown or overexpression of MRPL35 to confirm the functional relevance of observed expression differences.

How can researchers integrate MRPL35 antibody data with omics approaches in cancer research?

Integrating MRPL35 antibody data with omics approaches in cancer research creates powerful opportunities for comprehensive understanding:

• Proteogenomic integration: Correlate MRPL35 protein levels (detected by antibodies) with mRNA expression data to identify discrepancies that might indicate post-transcriptional regulation. Research has demonstrated that MRPL35 is up-regulated in gastric cancer at both protein and mRNA levels .

• Protein interaction networks: Combine immunoprecipitation using MRPL35 antibodies with mass spectrometry to identify protein interaction networks in cancer vs. normal cells. These can be integrated with publicly available interactome data to build cancer-specific interaction maps.

• Multi-omics correlation: Integrate MRPL35 protein expression data with metabolomics profiles, particularly focusing on mitochondrial metabolites, to establish functional relationships between MRPL35 levels and metabolic alterations in cancer.

• Clinical correlation: Combine immunohistochemistry data using MRPL35 antibodies with patient outcome data. Published research indicates that high expression of MRPL35 is associated with poor survival in gastric cancer patients .

• Pathway analysis: Integrate proteomic data following MRPL35 manipulation with pathway analysis tools to identify altered cellular pathways. Research has shown that knockdown of MRPL35 affects the expression of proteins like PICK1, BCL-XL, and AGR2, suggesting involvement in apoptotic pathways .

• Drug response correlation: Correlate MRPL35 expression levels with drug sensitivity profiles to identify potential predictive biomarkers for therapeutic response in cancer.

What are the best methodological approaches for investigating MRPL35 in different cancer types?

Investigating MRPL35 in different cancer types requires tailored methodological approaches:

• Expression profiling: Begin with comprehensive expression analysis using a combination of:

  • Immunohistochemistry on tissue microarrays covering multiple cancer types

  • Western blot analysis of cancer cell line panels

  • Mining public databases like UALCAN and KMplot, which have already been utilized to demonstrate MRPL35 upregulation in gastric cancer

• Functional studies: For cancers showing aberrant MRPL35 expression, implement:

  • Gene silencing using validated shRNA lentiviral vectors (as demonstrated in gastric cancer cells)

  • CRISPR/Cas9-mediated knockout for complete gene ablation

  • Doxycycline-inducible systems for temporal control of MRPL35 expression

• Phenotypic assays: Assess cancer-relevant phenotypes including:

  • Proliferation (using Celigo cell count assay as validated for gastric cancer)

  • Colony formation capabilities

  • Apoptosis (using flow cytometry)

  • Migration and invasion (transwell assays)

  • In vivo tumor formation in appropriate mouse models

• Mechanistic investigations: Implement proteomic analysis (such as isobaric tags for relative and absolute quantification) to identify downstream effectors, as successfully applied in gastric cancer research identifying PICK1, BCL-XL, and AGR2 as MRPL35-regulated proteins .

• Clinical correlation: Analyze the relationship between MRPL35 expression and clinicopathological features such as age, lymph node metastasis, and pathological stage, which have shown significant correlations in gastric cancer .

How can researchers address specificity concerns when MRPL35 antibodies cross-react with mouse tissues?

Addressing specificity concerns when MRPL35 antibodies cross-react with mouse tissues requires systematic validation and experimental design considerations:

• Species-specific sequence analysis: Perform sequence alignment between human and mouse MRPL35 to identify regions of homology. The PACO07202 antibody is documented to cross-react with mouse samples , which can be beneficial for translational studies but requires careful validation.

• Knockout/knockdown validation: Utilize MRPL35 knockout or knockdown mouse models to confirm antibody specificity. The absence or reduction of signal in these models provides strong evidence of specificity despite cross-reactivity.

• Pre-absorption controls: Perform pre-absorption of the antibody with recombinant mouse MRPL35 protein to determine if the signal in mouse tissues is specifically due to MRPL35 recognition.

• Western blot validation: Confirm that the antibody detects a protein of the expected molecular weight in mouse tissues. Compare band patterns between human and mouse samples to identify potential differences in specificity.

• Alternative detection methods: Complement antibody-based detection with nucleic acid-based methods (e.g., in situ hybridization or RT-qPCR) that can be designed with species-specific probes or primers.

• Species-specific antibody development: If available resources permit, consider developing antibodies against epitopes that are unique to either human or mouse MRPL35 to eliminate cross-reactivity concerns.

• Experimental design adjustments: When using mouse models, include appropriate controls that account for potential cross-reactivity, such as isotype controls and samples from MRPL35-deficient mice.

How might MRPL35 antibodies contribute to understanding mitochondrial dysfunction in neurodegenerative diseases?

MRPL35 antibodies could significantly advance our understanding of mitochondrial dysfunction in neurodegenerative diseases through several innovative approaches:

• Biomarker development: MRPL35 antibodies could be used to assess alterations in mitochondrial ribosome composition in patient-derived samples, potentially serving as biomarkers for mitochondrial dysfunction in neurodegenerative conditions.

• Spatiotemporal analysis: Immunohistochemistry using MRPL35 antibodies on brain tissues from neurodegenerative disease models could reveal region-specific alterations in mitochondrial ribosome distribution and abundance, particularly in affected neurons.

• Post-translational modification profiling: Developing modification-specific MRPL35 antibodies (phospho-, ubiquitin-, or acetyl-specific) could identify disease-associated post-translational modifications that might affect mitochondrial ribosome function.

• Protein aggregation studies: MRPL35 antibodies could determine whether mitochondrial ribosomal proteins co-localize with disease-specific protein aggregates (e.g., β-amyloid in Alzheimer's disease or α-synuclein in Parkinson's disease), suggesting potential pathogenic mechanisms.

• Therapeutic target validation: Since MRPL35 coordinates Cox1, Cox2, and Cox3 synthesis and assembly , and cytochrome c oxidase dysfunction is implicated in neurodegeneration, MRPL35 antibodies could help validate therapeutic approaches targeting mitochondrial translation.

• iPSC disease modeling: MRPL35 antibodies could be invaluable for characterizing mitochondrial ribosome integrity in induced pluripotent stem cell-derived neurons from neurodegenerative disease patients, providing insights into disease mechanisms.

What are the most promising approaches for studying MRPL35 interactions with other mitochondrial ribosomal proteins?

Studying MRPL35 interactions with other mitochondrial ribosomal proteins presents several promising methodological approaches:

• Proximity-dependent biotin labeling: Techniques such as BioID or APEX2 with MRPL35 as the bait protein can identify proteins in close spatial proximity within the mitochondrial ribosome under various physiological conditions.

• Cross-linking mass spectrometry (XL-MS): This technique can capture and identify direct protein-protein interactions between MRPL35 and other mitochondrial ribosomal proteins, providing structural insights into these interactions.

• Co-immunoprecipitation with targeted mass spectrometry: Using MRPL35 antibodies for immunoprecipitation followed by targeted mass spectrometry can quantify interactions with specific mitochondrial ribosomal proteins of interest.

• Single-particle cryo-electron microscopy (cryo-EM): This technique can provide high-resolution structural information about MRPL35's position and interactions within the intact mitochondrial ribosome.

• Genetic complementation studies: Systematic mutagenesis of MRPL35, particularly focused on the Y275 residue which has been shown to be functionally important , followed by assessment of mitochondrial ribosome assembly can identify critical residues for protein-protein interactions.

• Split fluorescent protein complementation: This approach can visualize MRPL35 interactions with candidate mitochondrial ribosomal proteins in living cells, providing spatial and temporal information about these interactions.

• Hydrogen-deuterium exchange mass spectrometry (HDX-MS): This technique can identify conformational changes in MRPL35 upon binding to other mitochondrial ribosomal proteins, revealing the dynamics of these interactions.