SAR1A Gene
SAR1A: Secretion Associated Ras Related GTPase 1A
Gene Information Card
| Symbol | SAR1A |
|---|---|
| Full Name | Secretion Associated Ras Related GTPase 1A |
| Gene Type | protein-coding |
| Chromosomal Location | 10q22.1 |
| NCBI Gene ID | 56681 ncbi.nlm.nih.gov/gene/56681 |
| Ensembl ID | ENSG00000120063 |
| UniProt ID | Q9NR31 |
| OMIM ID | 607691 |
| HGNC ID | 10535 |
| Aliases | SAR1, SARA, SAR1B, SAR1A |
Description
SAR1A encodes a small GTPase of the ARF family that is a core component of the COPII coat complex. It regulates the budding of transport vesicles from the endoplasmic reticulum (ER) to the Golgi apparatus. Activation by the guanine nucleotide exchange factor SEC12 promotes GTP binding, membrane association, and recruitment of SEC23/24 and SEC13/31 to form COPII vesicles.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Chylomicron retention disease (CMRD) | Impaired COPII vesicle formation leads to defective chylomicron secretion from enterocytes | PMID: 12692552 |
| Combined deficiency of fat-soluble vitamins | Disrupted ER-to-Golgi transport of lipid-binding proteins | PMID: 12692552 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Adipose tissue | 12.3 | Medium |
| Small intestine | 18.7 | High |
| Liver | 15.2 | High |
| Pancreas | 10.1 | Medium |
| Brain | 6.8 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 14.5 | Cervical adenocarcinoma |
| HepG2 | 16.2 | Hepatocellular carcinoma |
| Caco-2 | 19.1 | Colorectal adenocarcinoma |
| MCF7 | 8.9 | Breast adenocarcinoma |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.533G>A (p.Arg178His) | Missense | <0.01% | Impaired GTP binding and COPII function |
| c.340C>T (p.Arg114Trp) | Missense | <0.01% | Reduced vesicle budding activity |
Mutation functional classification
Loss of Function (LOF)
Missense mutations in the GTP-binding domain reduce GTPase activity and COPII vesicle formation, leading to ER retention of cargo.
Gain of Function (GOF)
No gain-of-function mutations reported.
Dominant Negative (DN)
Some SAR1A mutants (e.g., T39N) act as dominant-negative by sequestering SEC12 and inhibiting wild-type function.
View complete mutation data：
Gene Ontology (GO)
| • GTP binding (GO:0005525) | • GTPase activity (GO:0003924) |
| • COPII vesicle coating (GO:0048208) | • ER to Golgi vesicle-mediated transport (GO:0006888) |
| • intracellular protein transport (GO:0006886) |
Pathways
• COPII-mediated vesicle transport (Reactome R-HSA-204005)
• ER to Golgi anterograde transport (Reactome R-HSA-199977)
• Endoplasmic reticulum to Golgi transport (KEGG hsa04141)
Protein Summary
SAR1A is a 198-amino-acid small GTPase that cycles between GDP-bound (inactive) and GTP-bound (active) states. In its active form, it associates with the ER membrane and recruits the COPII coat components SEC23/24 and SEC13/31, initiating vesicle budding. It is essential for the export of secretory and membrane proteins from the ER.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| SAR1A Knockout HEK293 Cell Line | EDJ-KQ3110 | Human | 56681 | Details Get a Quote |
| SAR1A Knockout A-549 Cell Line | EDJ-KQ24448 | Human | 56681 | Details Get a Quote |
| SAR1A Knockout HCT 116 Cell Line | EDJ-KQ24449 | Human | 56681 | Details Get a Quote |
| SAR1A Knockout HeLa Cell Line | EDJ-KQ24450 | Human | 56681 | Details Get a Quote |
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