Sodium-coupled neutral amino acid transporter system A (SNAT)

Amino acid transporter system A, primarily comprised of the solute carrier family 38 members SLC38A1 (SNAT1) and SLC38A2 (SNAT2), is a sodium-dependent transport system for small, neutral amino acids such as glutamine, alanine, and proline (Bröer, 2018). This system is distinguished by its sensitivity to the competitive substrate/inhibitor alpha-(methylamino)isobutyric acid (MeAIB) and its ability to transport substrates against significant concentration gradients by coupling to the sodium electrochemical gradient (MedChemExpress). Biologically, system A transporters are essential for cellular nutrient supply, intracellular pH regulation, and the maintenance of osmotic pressure (Gauthier-Coles et al., 2022). In the central nervous system, they play a critical role in the glutamate-glutamine cycle by facilitating glutamine uptake into neurons to maintain neurotransmitter homeostasis. In the context of disease, these transporters are frequently overexpressed in various malignancies, including breast and pancreatic cancers, where they fuel the high metabolic demands of rapidly proliferating cells (Mark Foundation, 2025). Consequently, they have emerged as promising therapeutic targets, with experimental inhibitors like MMTC under investigation to disrupt tumor nutrient supply and sensitize cells to metabolic stress (Nielsen et al., 2024).

Other names

System ASystem A amino acid transporterSLC38A1SLC38A2SLC38A4ATA1ATA2SAT1SAT2SNAT1SNAT2SNAT4Small neutral amino acid transporter

Competitive inhibition of sodium-dependent neutral amino acid transport