MRPS24 (mitochondrial ribosomal protein S24) is a protein-coding gene in the species Homo sapiens that encodes a component of the mitochondrial ribosome. The protein is a member of the ribosomal protein S24 family and is incorporated into the small (28 S) subunit of the mitochondrial ribosome, where it participates in the translation of mitochondrial messenger RNAs.
Gene and Genomic Location
- Official Symbol: MRPS24
- Chromosomal Locus: 5p13.1 (based on the GRCh38/hg38 human genome assembly)
- Gene Type: Protein-coding
Protein Characteristics
- Molecular Weight: Approximately 21 kDa
- Amino Acid Length: Roughly 190 residues (the exact length may vary slightly among isoforms)
- Subcellular Localization: Mitochondrial matrix, as part of the mitochondrial ribosome (28 S subunit)
Functional Role
MRPS24 is essential for the assembly and stability of the mitochondrial small ribosomal subunit. The mitochondrial ribosome translates the 13 protein-coding genes encoded by the mitochondrial genome, which are core components of oxidative phosphorylation complexes. By contributing to the ribosome’s structural integrity, MRPS24 indirectly supports mitochondrial protein synthesis and respiratory chain function.
Clinical Significance
Pathogenic variants in MRPS24 have been associated with mitochondrial disease phenotypes. Notably, recessive mutations have been reported in individuals with Combined Oxidative Phosphorylation Deficiency 19 (COXPD19), a disorder characterized by:
- Early‑onset neurodevelopmental delay
- Hypotonia and muscle weakness
- Lactic acidosis
- Variable involvement of other organ systems (e.g., cardiac, hepatic)
These clinical manifestations reflect impaired mitochondrial translation and consequent deficiency of oxidative phosphorylation complexes.
Biological Interactions
MRPS24 interacts with other mitochondrial ribosomal proteins to form the functional small subunit. It has been detected in immunoprecipitation studies as part of ribonucleoprotein complexes that bind mitochondrial rRNA. Specific protein‑protein interaction partners beyond the ribosomal assembly are not extensively characterized.
Research and Experimental Data
- Expression: Ubiquitously expressed, with higher levels in tissues with high metabolic demand such as heart, skeletal muscle, and brain.
- Knock‑down/Knock‑out Studies: Cellular models with reduced MRPS24 expression exhibit diminished mitochondrial protein synthesis, reduced activity of respiratory chain complexes, and increased reliance on glycolytic metabolism.
References
(Information summarized from peer‑reviewed literature, gene databases such as NCBI Gene, UniProt, and clinical case reports on MRPS24‑related mitochondrial disease.)