Secretion associated Ras related GTPase 1A (SAR1A)

Secretion associated Ras related GTPase 1A (SAR1A) is a small GTPase essential for the formation of COPII-coated vesicles which mediate the transport of proteins from the endoplasmic reticulum to the Golgi apparatus[1][2][3][4]. SAR1A switches between an inactive GDP-bound and active GTP-bound state, recruiting the COPII coat to the ER membrane and driving vesicle formation and cargo selection[1][2]. It also functions as a leucine sensor regulating TORC1 signaling and cellular metabolism, a property independent of its GTPase activity[1]. SAR1A is critical for cell viability—as demonstrated by embryonic lethality upon knockout in mice—and shows functional overlap with its paralog SAR1B; upregulation of SAR1A can compensate for SAR1B deficiency, suggesting therapeutic potential in rare lipid transport disorders[3][4]. No human disease has been directly attributed to SAR1A mutation, but its perturbation would severely disrupt protein secretion. No clinically approved drugs target SAR1A, nor are there known biomarkers or safety profiles for therapeutic modulation.

Other names

SAR1SARASaraSARA1COPII-associated small GTPaseSmall COPII coat GTPase SAR1AGTP-binding protein SAR1aSAR1 gene homolog ASAR1 homolog ASAR1a gene homolog 1masra2

Experimental: gene expression upregulation to compensate for SAR1B deficiency, thereby restoring normal vesicle trafficking and lipid secretion