NSUN3
NOP2/Sun RNA Methyltransferase 3
Gene Information Card
| Symbol | NSUN3 |
|---|---|
| Full Name | NOP2/Sun RNA Methyltransferase 3 |
| Gene Type | Protein coding |
| Chromosomal Location | 3q11.2 |
| NCBI Gene ID | 63899 ncbi.nlm.nih.gov/gene/63899 |
| Ensembl ID | ENSG00000138621 |
| UniProt ID | Q96H44 |
| OMIM ID | 617491 |
| HGNC ID | 26423 |
| Aliases | MISU, NOL1/NOP2/Sun domain family member 3 |
Description
NSUN3 is a nuclear-encoded mitochondrial RNA methyltransferase that specifically catalyzes the formation of 5-methylcytosine (m5C) at position 34 of mitochondrial tRNA-Met. This modification is essential for efficient mitochondrial translation and oxidative phosphorylation. Loss-of-function mutations in NSUN3 cause combined oxidative phosphorylation deficiency 48 (COXPD48), a mitochondrial disorder characterized by developmental delay, hypotonia, and lactic acidosis.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Combined oxidative phosphorylation deficiency 48 (COXPD48) | Loss-of-function mutations impair m5C34 modification of mitochondrial tRNA-Met, leading to defective mitochondrial translation and reduced ATP production. | PMID: 27543988, 27543989 |
| Mitochondrial encephalopathy | Defective mitochondrial protein synthesis due to NSUN3 deficiency results in impaired respiratory chain complex assembly. | PMID: 27543988 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | 8.2 | Medium |
| Heart | 6.5 | Medium |
| Skeletal muscle | 5.1 | Medium |
| Brain | 4.3 | Low |
| Kidney | 3.8 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HepG2 | 7.9 | Hepatocellular carcinoma cell line |
| K562 | 6.1 | Chronic myeloid leukemia cell line |
| HeLa | 5.4 | Cervical carcinoma cell line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1?) | Missense | Rare | Loss of start codon, no protein produced |
| c.208C>T (p.Arg70*) | Nonsense | Rare | Premature stop, loss of function |
| c.424G>A (p.Gly142Arg) | Missense | Rare | Impaired catalytic activity |
Mutation functional classification
Loss of Function (LOF)
Pathogenic variants (e.g., p.Met1?, p.Arg70*) result in complete loss of methyltransferase activity, causing COXPD48.
Gain of Function (GOF)
Not reported.
Dominant Negative (DN)
Not reported.
View complete mutation data：
Gene Ontology (GO)
| • RNA methyltransferase activity | • tRNA binding |
| • mitochondrion | • 5-methylcytosine modification |
| • mitochondrial translation |
Pathways
• Mitochondrial tRNA modification
• Oxidative phosphorylation
Protein Summary
NSUN3 is a 346-amino acid protein localized to the mitochondrial matrix. It contains a conserved NOL1/NOP2/Sun (NSUN) domain responsible for methyltransferase activity. The protein specifically targets cytosine 34 in mitochondrial tRNA-Met, converting it to 5-methylcytosine. This modification is critical for proper codon-anticodon pairing and efficient mitochondrial protein synthesis.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| NSUN3 Knockout HEK293 Cell Line | EDJ-KQ14502 | Human | 63899 | Details Get a Quote |
| NSUN3 Knockout A-549 Cell Line | EDJ-KQ44769 | Human | 63899 | Details Get a Quote |
| NSUN3 Knockout HCT 116 Cell Line | EDJ-KQ44770 | Human | 63899 | Details Get a Quote |
| NSUN3 Knockout HeLa Cell Line | EDJ-KQ44771 | Human | 63899 | Details Get a Quote |
Displaying Records 1 To 4 Of 4 Records
