Cationic amino acid transporter 1 (CAT-1 (also SLC7A1))

Cationic amino acid transporter 1 (CAT-1, SLC7A1) is a high-affinity, low-capacity permease responsible for mediating the sodium-independent uptake and efflux of cationic amino acids—primarily arginine, but also lysine and ornithine—across the plasma membrane of non-hepatic mammalian cells. This transporter is essential for supplying cells with arginine, a vital substrate for nitric oxide (NO) synthesis and a regulator of key metabolic and signaling pathways, including the mTORC1 axis. CAT-1 belongs to the solute carrier family 7 (SLC7) and is widely expressed except in adult liver. It has become a focus of interest as a potential cancer therapeutic target based on findings that some tumor cells (such as chronic lymphocytic leukemia) exhibit a unique dependency on CAT-1-mediated arginine import to support their growth and survival. Inhibition of CAT-1 affects processes including cellular metabolism, immune responses (by modulating NO production), and cell proliferation. Pharmacological targeting remains a challenge due to its widespread physiological roles and the risk of on-target toxicity.

Other names

CAT-1SLC7A1High affinity cationic amino acid transporter 1hCAT-1Arginine transporter 1

Inhibition of CAT-1 reduces cellular uptake of arginine and related cationic amino acids, impairing NO synthesis and mTOR signaling, which can affect cell proliferation and survival—especially in tumor cells reliant on extracellular arginine