MRPL50 Antibody

What is MRPL50 and what cellular functions does it serve?

MRPL50 is a component of the large 39S subunit of the mammalian mitochondrial ribosome. Mitochondrial ribosomes (mitoribosomes) are responsible for the translation of mitochondrially-encoded proteins, particularly those comprising the oxidative phosphorylation machinery. Unlike prokaryotic ribosomes, mitoribosomes have an estimated 75% protein to rRNA composition and lack 5S rRNA. MRPL50 belongs to the L47P ribosomal protein family and is encoded by a nuclear gene located on chromosome 9 . Recent research has demonstrated that MRPL50 deficiency can destabilize the large subunit of the mitochondrial ribosome, resulting in defective complex I biogenesis and multiple systemic pathologies .

What are the molecular characteristics of MRPL50 protein?

MRPL50 is a relatively small protein with 158 amino acids and a calculated molecular weight of approximately 18 kDa, which corresponds to its observed molecular weight in Western blot analyses . The protein is also known by several aliases including 39S ribosomal protein L50, mitochondrial; L50mt; and Large ribosomal subunit protein mL50 . The human MRPL50 gene is identified by Entrez Gene ID 54534 and UniProt ID Q8N5N7 .

Which MRPL50 antibodies are commercially available for research?

Several validated MRPL50 antibodies are available for research applications:

What are the validated applications for MRPL50 antibodies?

MRPL50 antibodies have been validated for multiple experimental applications:

• Western Blotting (WB): All commercially available antibodies have been validated for Western blotting, with recommended dilutions typically ranging from 1:500 to 1:2000 .

• Immunohistochemistry (IHC): Some antibodies (e.g., Proteintech 17213-1-AP) have been validated for IHC applications with recommended dilutions of 1:50 to 1:500 .

• ELISA: Select antibodies have been validated for ELISA applications .

• Research Applications: MRPL50 antibodies have been employed in studies investigating mitochondrial ribosome biogenesis, oxidative phosphorylation defects, and pathological conditions associated with mitoribosomal dysfunction .

What is the optimal protocol for Western blotting using MRPL50 antibodies?

Based on published research methodologies, the following protocol has been effectively used for Western blotting with MRPL50 antibodies:

• Protein Extraction:

  • Extract proteins from cultured cells (e.g., fibroblasts) using extraction buffer A (MitoSciences)

  • Quantify protein using Pierce BCA protein assay kit with BSA standards

• Sample Preparation:

  • Prepare 5 μg of total protein lysate with 2X solubilization buffer (125 mM Tris pH 8.0, 40% glycerol, 4% SDS, 100 mM DTT, bromophenol blue)

  • Add Complete mini protease inhibitor (Roche)

  • Heat samples at 94°C for 3 minutes

• Electrophoresis and Transfer:

  • Run samples on 10% Bis-Tris NuPAGE gels with MOPS or MES buffer

  • Transfer proteins to PVDF membranes

• Antibody Incubation:

  • Block membranes using 5% skim milk powder in TBST

  • Incubate with primary anti-MRPL50 antibody (1:500-1:2000 dilution) overnight at 4°C

  • Wash with TBST

  • Incubate with appropriate secondary antibody (e.g., swine anti-rabbit HRP at 1:20,000) at room temperature for 2 hours

• Detection:

  • Detect proteins using ECL Prime Western blotting detection system

  • Visualize with appropriate imaging system

What are the recommended procedures for immunohistochemistry with MRPL50 antibodies?

For optimal IHC results with MRPL50 antibodies:

• Antigen Retrieval:

  • Primary recommendation: TE buffer pH 9.0

  • Alternative: Citrate buffer pH 6.0

• Antibody Dilution:

  • Use dilutions ranging from 1:50 to 1:500 depending on sample type and detection system

• Positive Control Tissues:

  • Human liver tissue has been validated for positive staining

• Considerations:

  • Optimize antibody concentration for each specific testing system

  • Sample-dependent results may require further optimization

How can MRPL50 antibodies be used to investigate mitochondrial ribosome assembly defects?

MRPL50 antibodies serve as valuable tools for investigating mitochondrial ribosome assembly defects through multi-faceted approaches:

• Subunit Stability Assessment: Research has demonstrated that MRPL50 deficiency specifically destabilizes the large subunit (39S) of the mitochondrial ribosome while preserving the small subunit (28S). This can be evaluated using Western blot analysis with antibodies targeting multiple mitoribosomal proteins:

  • MRPL50 antibody to confirm protein deficiency

  • Other large subunit proteins (MRPL13, MRPL44, MRPL39, MRPL9) to assess collateral destabilization

  • Small subunit proteins (MRPS17, MRPS7) to confirm preservation of the small subunit

• Quantitative Proteomics: MRPL50 antibodies can be used in immunoprecipitation protocols prior to mass spectrometry analysis to identify interaction partners and structural alterations in pathological conditions .

• Oxidative Phosphorylation Assessment: Since mitochondrial ribosomes translate components of the oxidative phosphorylation complexes, MRPL50 antibodies can be used alongside antibodies against OXPHOS complexes (e.g., Total OXPHOS Human WB antibody Cocktail) to correlate ribosomal defects with respiratory chain dysfunction .

What experimental approaches can validate the pathogenicity of MRPL50 variants?

Research has established several experimental approaches to validate the pathogenicity of MRPL50 variants:

• Patient Fibroblast Analysis:

  • Western blotting to assess MRPL50 protein levels

  • Quantitative proteomics to evaluate mitoribosomal subunit integrity

  • Analysis of oxidative phosphorylation complex abundance

• Expression Analysis:

  • RNA extraction and cDNA synthesis

  • qRT-PCR using appropriate reference genes (e.g., GAPDH)

  • Calculation of relative expression using efficiency-corrected formula: E(GAPDH)^Ct(GAPDH)/E(MRPL50)^Ct(MRPL50)

• Drosophila Modeling:

  • RNAi-mediated knockdown of mRpL50 (Drosophila ortholog)

  • CRISPR/Cas9-mediated mRpL50-gRNA knockout

  • Tissue-specific expression analysis using somatic cell-specific and germline-specific Gal4 drivers

  • Assessment of phenotypic outcomes in reproductive and developmental contexts

How do MRPL50 deficiencies impact mitochondrial function and disease pathogenesis?

Research utilizing MRPL50 antibodies has revealed important insights into the relationship between MRPL50 deficiency and disease pathogenesis:

• Mitochondrial Translation Defects: MRPL50 deficiency destabilizes the large mitoribosomal subunit, impairing mitochondrial protein synthesis.

• Oxidative Phosphorylation Deficiency: Patient fibroblasts harboring MRPL50 variants show a mild but significant decrease in the abundance of mitochondrial complex I, linking mitoribosomal dysfunction to respiratory chain defects.

• Syndromic Clinical Presentations: Pathogenic MRPL50 variants have been associated with a syndromic presentation including:

  • Primary ovarian insufficiency (POI)

  • Bilateral high-frequency sensorineural hearing loss

  • Kidney dysfunction

  • Cardiac abnormalities (left ventricular hypertrophy)

• Developmental Impacts: Knockdown/knockout of mRpL50 in Drosophila results in abnormal ovarian development, supporting the critical role of mitochondrial function in reproductive tissue development .

What controls should be included when validating MRPL50 antibody specificity?

For rigorous validation of MRPL50 antibody specificity:

• Positive Controls:

  • Cell lines with confirmed MRPL50 expression (HT-1080, HeLa, HepG2)

  • Tissue samples with established expression (human liver)

• Negative Controls:

  • Primary antibody omission

  • Isotype control antibody

  • MRPL50 knockdown/knockout samples when available

• Multiple Antibody Validation:

  • Use of two different anti-MRPL50 antibodies targeting distinct epitopes, as demonstrated in research where both PA5-39246 and PA5-101675 were employed

• Loading Controls:

  • Alpha-Tubulin (HRP) (1:5000) has been successfully used as a loading control in MRPL50 Western blot experiments

What factors might affect the detection of MRPL50 in experimental systems?

Several factors can influence successful detection of MRPL50:

• Protein Extraction Method: The choice of extraction buffer is critical for mitochondrial proteins. Research has successfully used extraction buffer A (MitoSciences) for MRPL50 detection .

• Sample Preparation: Inadequate protein denaturation or degradation can affect detection. Complete protease inhibitors should be included during sample preparation.

• Antibody Selection: Different antibodies target distinct epitopes that may be differentially accessible depending on protein conformation or interactions.

• Crossreactivity: MRPL50 belongs to a family of mitochondrial ribosomal proteins with potentially similar domains. Antibody specificity should be validated in each experimental system.

• Expression Levels: MRPL50 expression may vary across tissues and cell types, requiring optimization of antibody concentration for each specific application.

How can researchers interpret changes in MRPL50 expression patterns in different pathological conditions?

Interpretation of MRPL50 expression changes should consider:

• Context of Mitoribosomal Assembly: Changes in MRPL50 expression should be evaluated in the context of other mitoribosomal proteins, especially other components of the large subunit.

• Impact on Mitochondrial Translation: Correlate MRPL50 expression changes with markers of mitochondrial protein synthesis efficiency.

• Tissue-Specific Effects: Research has shown that MRPL50 deficiency can have tissue-specific effects, particularly affecting high-energy demanding tissues such as ovaries, cochlea, kidneys, and heart .

• Genetic Background: Consider the influence of genetic variants and modifier genes when interpreting MRPL50 expression data.

• Quantification Approaches: Use appropriate quantification methods:

  • Western blot: Normalized band intensity relative to loading controls

  • qRT-PCR: Efficiency-corrected relative quantification against reference genes

  • Proteomics: Label-free quantitative MS or SILAC approaches

What are the implications of MRPL50 research for understanding mitochondrial disease mechanisms?

Research utilizing MRPL50 antibodies has expanded our understanding of mitochondrial disease mechanisms:

• Novel Disease Associations: The identification of MRPL50 variants in patients with syndromic primary ovarian insufficiency expands the spectrum of mitoribosomal diseases .

• Tissue-Specific Vulnerabilities: MRPL50 research highlights the differential vulnerability of tissues to mitoribosomal dysfunction, with particular impacts on ovarian development and function.

• Therapeutic Targeting: Understanding the precise molecular consequences of MRPL50 deficiency may inform targeted therapeutic approaches for mitochondrial diseases.

• Genotype-Phenotype Correlations: The characterization of specific MRPL50 variants (e.g., c.335T>A; p.Val112Asp) provides insights into structure-function relationships in mitoribosomal proteins .