MRPS21: Mitochondrial Ribosomal Protein S21
A core component of the mitochondrial small ribosomal subunit essential for intra-mitochondrial protein synthesis.
Gene Information Card
| Symbol | MRPS21 |
|---|---|
| Full Name | Mitochondrial Ribosomal Protein S21 |
| Gene Type | Protein coding |
| Chromosomal Location | 1q21.2 |
| NCBI Gene ID | 54460 ncbi.nlm.nih.gov/gene/54460 |
| Ensembl ID | ENSG00000117519 |
| UniProt ID | P82921 |
| OMIM ID | 611984 |
| HGNC ID | 14048 |
| Aliases | MRP-S21, S21mt, RPMS21, COXPD51 |
Description
MRPS21 encodes a 21S mitochondrial ribosomal protein (MRP-S21) that is a component of the mitochondrial small ribosomal subunit (28S). This protein is essential for mitochondrial translation, enabling the synthesis of 13 subunits of the oxidative phosphorylation (OXPHOS) system encoded by the mitochondrial genome. Defects in MRPS21 can impair mitochondrial protein synthesis, leading to combined OXPHOS deficiency and mitochondrial disease.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Combined Oxidative Phosphorylation Deficiency 51 (COXPD51) | Loss-of-function mutations in MRPS21 impair mitochondrial translation, reducing the synthesis of OXPHOS subunits and causing multi-system mitochondrial dysfunction. | ClinVar, OMIM #619028 |
| Mitochondrial Complex I Deficiency | Defective mitochondrial translation due to MRPS21 mutations leads to reduced assembly and activity of respiratory chain complex I. | OMIM, literature (Kohda et al., 2016) |
| Leigh Syndrome | Biallelic MRPS21 variants have been reported in patients with Leigh-like neuropathology, associated with mitochondrial respiratory chain defects. | ClinVar, case reports |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Heart | 12.3 | Medium |
| Skeletal Muscle | 10.8 | Medium |
| Liver | 8.5 | Medium |
| Brain | 7.2 | Low |
| Kidney | 6.9 | Low |
| Testis | 5.4 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK 293 | 15.2 | High expression in embryonic kidney cells |
| HeLa | 12.7 | High expression in cervical cancer cells |
| HepG2 | 9.8 | Moderate expression in liver cancer cells |
| K562 | 6.3 | Low expression in leukemia cells |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.194G>A (p.Arg65His) | Missense | Rare (gnomAD 0.0004%) | Likely loss-of-function; impairs ribosomal assembly |
| c.287_288del (p.Glu96Glyfs*12) | Frameshift | Not reported in population databases | Loss-of-function; premature truncation |
| c.1A>G (p.Met1?) | Start loss | Very rare | Loss-of-function; abolishes translation initiation |
Mutation functional classification
Loss of Function (LOF)
Most reported MRPS21 mutations are loss-of-function (missense, frameshift, start loss) leading to reduced mitochondrial translation and OXPHOS deficiency.
Gain of Function (GOF)
No gain-of-function mutations have been described for MRPS21.
Dominant Negative (DN)
No dominant-negative effects have been reported; disease is recessive.
View complete mutation data：
Gene Ontology (GO)
| • structural constituent of ribosome (GO:0003735) | • mitochondrial small ribosomal subunit (GO:0005763) |
| • translation (GO:0006412) | • mitochondrial translation (GO:0032543) |
| • mitochondrion (GO:0005739) |
Pathways
• Mitochondrial translation (Reactome: R-HSA-5389840)
• Respiratory electron transport (Reactome: R-HSA-611105)
• Organelle biogenesis and maintenance (Reactome: R-HSA-1852241)
Protein Summary
MRPS21 (Mitochondrial Ribosomal Protein S21) is a 21S protein component of the mitochondrial small ribosomal subunit (28S). It is encoded by the nuclear gene MRPS21 and imported into mitochondria. MRPS21 directly participates in decoding mitochondrial mRNAs and is essential for the synthesis of 13 OXPHOS subunits. The mature protein is 87 amino acids long (after mitochondrial targeting signal cleavage) and contains a ribosomal protein S21 domain. Loss of MRPS21 function leads to combined oxidative phosphorylation deficiency, manifesting as Leigh syndrome or other mitochondrial encephalopathies.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| MRPS21 Knockout HEK293 Cell Line | EDJ-KQ51365 | Human | 54460 | Details Get a Quote |
| MRPS21 Knockout HeLa Cell Line | EDJ-KQ56419 | Human | 54460 | Details Get a Quote |
| MRPS21 Knockout A-549 Cell Line | EDJ-KQ64912 | Human | 54460 | Details Get a Quote |
| MRPS21 Knockout HCT 116 Cell Line | EDJ-KQ73356 | Human | 54460 | Details Get a Quote |
