Solute carrier family 38 member 9 (SLC38A9)

SLC38A9 is a **lysosomal membrane protein** that functions as both an amino acid transporter and a nutrient sensor (“transceptor”) for the mTORC1 pathway[1][2][3]. It is a member of the **solute carrier 38 family** of sodium-coupled amino acid transporters and the larger APC superfamily[3]. SLC38A9 mediates low capacity, relatively low specificity influx of several polar and neutral amino acids, with a particular role as an arginine sensor. By physically interacting with the Ragulator and Rag GTPase complexes at the lysosome, SLC38A9 signals arginine sufficiency to mTORC1, thus promoting cellular growth and anabolic processes[2][6][7]. Its dual transport and signaling function is essential for lysosomal amino acid homeostasis and metabolic adaptation. SLC38A9 is also reported as upregulated in some cancers, including lung cancer, and emerging evidence suggests a possible role in sensing lysosomal cholesterol levels[7]. No specific clinically approved drugs are known to directly target SLC38A9 as of mid-2024.

Other names

Neutral amino acid transporter 9SNAT9Up-regulated in lung cancer 11URLC11FLJ90709Sodium-coupled neutral amino acid transporter 9

Transport of amino acids across lysosomal membrane (sodium-coupled) Sensors/signalers to Rag GTPases and Ragulator complex for mTORC1 activation in response to amino acid (especially arginine) and cholesterol levels