MRPL48 Human
Description
Molecular Structure and Functional Role
MRPL48 (mitochondrial ribosomal protein L48) is a nuclear-encoded protein integral to the mitochondrial large ribosomal subunit (39S). It plays a critical role in mitochondrial protein synthesis, facilitating the translation of mitochondrial DNA-encoded proteins .
Key Functions:
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Structural Component: Stabilizes the 39S ribosomal subunit during translation .
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Translational Regulation: Interacts with other ribosomal proteins (e.g., MRPL46, MRPS30) to ensure accurate peptide elongation .
Clinical Relevance in Cancer
MRPL48 is implicated in cancer progression, particularly in breast cancer (BC).
Expression Patterns in Breast Cancer Subtypes
MRPL48 exhibits subtype-specific upregulation:
Mechanistic Insights:
Interaction Network and Functional Partners
MRPL48 forms functional complexes with mitochondrial ribosomal proteins and regulators:
Pathway Involvement:
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Mitochondrial Translational Termination: Partners with MRPL47 and MRPS18C to terminate translation .
Subcellular Localization and Tissue Expression
MRPL48 is mitochondrion-specific, with consistent localization across human tissues:
| Tissue | Expression Level | Source |
|---|---|---|
| Liver | High | Human Protein Atlas |
| Brain | Moderate | Allen Brain Atlas |
| Breast (Cancerous) | Variable | TCGA/CCLE |
Functional Validation:
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Recombinant Protein Studies: Denatured MRPL48 (18.7 kDa) retains mitochondrial localization signals upon refolding .
Chemical Modulators and Therapeutic Implications
Environmental and pharmacological agents alter MRPL48 expression:
Therapeutic Potential:
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Targeting MRPL48: Inhibiting MRPL48 in basal-like BC may suppress mitochondrial protein synthesis and tumor growth .
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Biomarker Utility: MRPL48 expression levels could guide personalized therapy in BC subtypes .
Prognostic Models and Clinical Applications
A MRP-based nomogram integrating MRPL48 with MRPL16, MRPL40, MRPS18C, and MRPS35 predicts breast cancer survival:
| Marker | Prognostic Impact | HR (95% CI) | P-value |
|---|---|---|---|
| MRPL48 | Not included in final model | – | – |
| MRPL16 | Protective (↑ → longer OS) | 0.663 (0.456–0.963) | 0.031 |
| MRPS35 | Risk (↑ → shorter OS) | 1.48 (1.047–2.092) | 0.027 |
Clinical Utility:
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Nomogram Accuracy: Demonstrated good discrimination (C-index ≈ 0.75) for predicting 5-year OS in BC patients .
Research Gaps and Future Directions
Product Specs
Product Science Overview
Mitochondrial Ribosomal Protein L48 (MRPL48) is a crucial component of the mitochondrial ribosome, specifically the large 39S subunit. Mitochondrial ribosomes, or mitoribosomes, are essential for protein synthesis within the mitochondria, the powerhouse of the cell. Unlike prokaryotic ribosomes, mitoribosomes have a higher protein-to-rRNA ratio and lack a 5S rRNA component .
Recombinant MRPL48 is typically produced using bacterial expression systems such as Escherichia coli (E. coli). The gene encoding MRPL48 is cloned into an expression vector, which is then introduced into E. coli cells. The bacteria are cultured, and the protein is expressed and subsequently purified using affinity chromatography techniques. The recombinant protein often includes a His-tag to facilitate purification .
The recombinant MRPL48 protein is analyzed using various biochemical techniques to confirm its purity and functionality. Common methods include:
- SDS-PAGE: This technique is used to determine the purity and molecular weight of the protein.
- Western Blotting: This method is employed to verify the presence of the His-tag and to confirm the identity of the protein.
- Mass Spectrometry: This technique provides detailed information about the protein’s molecular weight and post-translational modifications .
Recombinant MRPL48 is used in various research applications, including studies on mitochondrial function, protein synthesis, and the role of mitoribosomes in health and disease. It serves as a valuable tool for understanding the molecular mechanisms underlying mitochondrial disorders and for developing potential therapeutic strategies .
