SAR1A (Secretion-Associated RAS-Related GTPase 1A) is a small GTPase that regulates COPII vesicle formation during protein export from the endoplasmic reticulum. SAR1A is essential for the early steps of vesicular trafficking and has implications for protein quality control mechanisms important in neurodegenerative diseases.
| Secretion Associated Ras Related GTPase 1A | |
|---|---|
| Gene Symbol | SAR1A |
| Full Name | Secretion Associated Ras Related GTPase 1A |
| Chromosome | 10q21.3 |
| NCBI Gene ID | 124454 |
| OMIM | 607751 |
| Ensembl ID | ENSG00000094841 |
| UniProt ID | Q9Y5B1 |
| Associated Diseases | Congenital Disorder of Glycosylation, Neurodevelopmental Disorders |
SAR1A encodes a small GTPase that is essential for COPII vesicle formation at the endoplasmic reticulum. The COPII coat complex (SAR1-SEC23-SEC24-SEC13-SEC31) mediates the transport of newly synthesized proteins from the ER to the Golgi apparatus. SAR1A initiates COPII coat assembly by recruiting cargo receptors and facilitating membrane curvature. In neurons, SAR1A-mediated trafficking is crucial for the secretion of neurosecretory proteins and the transport of synaptic components.
Ubiquitously expressed with high levels in secretory tissues and brain. Neuronal expression supports synaptic protein trafficking.
| Disease | Variants | Inheritance | Mechanism |
|---|---|---|---|
| Congenital Disorder of Glycosylation IIb | Biallelic variants | Autosomal Recessive | Defective COPII trafficking |
| Neurodevelopmental Disorders | Various | Various | Impaired protein secretion |