Solute carrier family 7 member 3 (SLC7A3)

Solute carrier family 7 member 3 (SLC7A3) is a sodium-independent cationic amino acid transporter that belongs to the CAT subfamily of the SLC7 family[1]. The protein serves as a uniporter that mediates the uptake of cationic L-amino acids, particularly L-arginine, L-lysine, and L-ornithine[3]. SLC7A3 is encoded by a gene located on chromosome Xq13.1 and produces a 619-amino acid protein with 14 transmembrane domains[2]. The transporter plays a crucial role in neuronal function, with selective expression in the brain[5]. It facilitates the transport of essential amino acids through passive diffusion in a sodium-independent and pH-independent manner[3]. The protein is moderately trans-stimulated and does not require energy coupling for its transport function[3]. SLC7A3 has significant importance in neuronal development and plasticity through its regulation of arginine availability, which affects the mammalian target of rapamycin (mTOR) signaling pathway[2][5]. The transporter responds to NMDA receptor activation and helps control cellular processes critical for brain function[5]. Arginine transported by SLC7A3 serves as a precursor for nitric oxide synthesis, creatine production, and polyamine synthesis through ornithine[5]. Clinical significance includes associations with autism spectrum disorders, where rare hypomorphic variants in SLC7A3 have been identified in male patients[4][5]. Functional studies have shown that certain missense variants can cause severe or moderate loss of CAT-3 function due to altered protein stability or abnormal trafficking to the plasma membrane[5]. The gene is highly intolerant to variation in humans, as evidenced by the low frequency of deleterious variants in population databases[5].

Other names

CAT-3CAT3ATRC3Cationic amino acid transporter 3Cationic amino acid transporter y+CTR3

Cationic amino acid transport, Arginine uptake facilitation