Cationic amino acid transporter 3 (CAT-3)

Cationic amino acid transporter 3 (CAT-3) is a sodium-independent membrane transporter responsible for the uptake of cationic amino acids such as arginine, lysine, and ornithine, and is encoded by the SLC7A3 gene in humans. It is primarily expressed in the brain and plays a crucial role in neuronal physiology, modulating signalling pathways including nitric oxide synthesis (by controlling arginine availability) and the mammalian target of rapamycin (mTOR) pathway, which is vital for neuronal growth, differentiation, and synaptic plasticity. Variants in CAT-3 have been implicated in neurodevelopmental disorders, such as autism spectrum disorder, as well as being of interest in other diseases due to the transporter's fundamental role in cell metabolism. While no approved drugs directly target CAT-3, it is of therapeutic interest, with the broader family of amino acid transporters being explored as drug targets, notably in cancer and neurological conditions. The main therapeutic challenge is the essential role of cationic amino acid transport in various cell types, making safety and selectivity a concern for any potential targeted interventions.

Other names

SLC7A3ATRC3CAT3Cationic amino acid transporter y+Solute carrier family 7 member 3

Drugs acting on CAT-3 would generally function as competitive inhibitors of cationic amino acid transport, reducing intracellular supply of substrates like arginine, and thereby affecting downstream processes such as NO synthesis and mTOR signalling