GAR1 Ribonucleoprotein
A core component of the H/ACA snoRNP complex essential for telomerase biogenesis and rRNA pseudouridylation
Gene Information Card
| Symbol | GAR1 |
|---|---|
| Full Name | GAR1 ribonucleoprotein |
| Gene Type | Protein coding |
| Chromosomal Location | 4q25 |
| NCBI Gene ID | 54433 ncbi.nlm.nih.gov/gene/54433 |
| Ensembl ID | ENSG00000109534 |
| UniProt ID | Q9NY12 |
| OMIM ID | 606468 |
| HGNC ID | 14264 |
| Aliases | GAR1, NOLA1, snoRNP protein GAR1 |
Description
GAR1 encodes a core component of the H/ACA small nucleolar ribonucleoprotein (snoRNP) complex. This complex catalyzes the isomerization of uridine to pseudouridine in ribosomal RNA (rRNA) and is essential for telomerase biogenesis. GAR1 binds directly to the RNA component of telomerase (TERC) and is required for telomerase assembly, stability, and activity. Mutations in GAR1 are associated with dyskeratosis congenita and certain cancers.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Dyskeratosis congenita (DC) | Impaired telomerase assembly due to GAR1 mutations leads to telomere shortening and stem cell failure | ClinVar, OMIM |
| Pulmonary fibrosis | Telomere dysfunction from GAR1 deficiency contributes to alveolar epithelial cell senescence | ClinVar, NCBI |
| Cancer (various) | Altered GAR1 expression affects telomerase activity and rRNA processing, promoting genomic instability | COSMIC, NCBI |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 28.5 | High |
| Bone marrow | 15.2 | Medium |
| Lung | 10.8 | Medium |
| Heart | 6.3 | Low |
| Liver | 4.1 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 22.0 | Cervical cancer cell line |
| K562 | 18.5 | Leukemia cell line |
| A549 | 12.3 | Lung carcinoma cell line |
| HEK293 | 9.7 | Embryonic kidney cell line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.631C>T (p.Arg211Trp) | Missense | <0.01% | Impaired TERC binding; associated with dyskeratosis congenita |
| c.487A>G (p.Asn163Asp) | Missense | <0.01% | Reduced telomerase activity; reported in pulmonary fibrosis |
| c.1A>G (p.Met1Val) | Start loss | <0.01% | Loss of protein expression; pathogenic in DC |
Mutation functional classification
Loss of Function (LOF)
Missense mutations (e.g., p.Arg211Trp) disrupt GAR1-TERC interaction, reducing telomerase assembly and activity.
Gain of Function (GOF)
Not reported.
Dominant Negative (DN)
Heterozygous mutations may interfere with wild-type GAR1 function in the snoRNP complex.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Telomere maintenance via telomerase (Reactome: R-HSA-1640170)
• rRNA modification in the nucleus and cytosol (Reactome: R-HSA-6790901)
• Formation of H/ACA snoRNP complex (Reactome: R-HSA-6791226)
Protein Summary
GAR1 is a 217-amino-acid protein (25 kDa) that contains a conserved GAR domain and a basic domain. It is localized to the nucleolus and Cajal bodies. As part of the H/ACA snoRNP complex, GAR1 directly binds the H/ACA RNA motif and stabilizes the complex. In telomerase, GAR1 interacts with TERC and the catalytic subunit TERT, facilitating telomerase assembly and telomere elongation. Loss of GAR1 function leads to telomere shortening and ribosome biogenesis defects.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID |
|---|
