Proton-coupled amino acid transporter 1 (SLC36A1) (PAT1)

Proton-coupled amino acid transporter 1 (SLC36A1), also known as LYAAT1 or PAT1, is a lysosomal and plasma membrane transporter that mediates the symport of small neutral amino acids, such as glycine, alanine, and proline, with protons [11, 15, 19]. It is highly expressed in the small intestine, where it facilitates the absorption of nutrients and various amino acid-mimetic drugs, and in the brain, where it is primarily localized to lysosomes [18, 19, 21]. SLC36A1 functions as a "transceptor," integrating its transport activity with the sensing of luminal amino acid levels to activate the mTORC1 signaling pathway, a master regulator of cell growth and metabolism [9, 24]. Due to its role in nutrient sensing and drug delivery, SLC36A1 is a target of interest in oncology, as its overexpression can drive tumor proliferation through sustained mTORC1 activation [9, 10]. Additionally, it serves as a key route for the oral delivery of therapeutic agents like the antiepileptic vigabatrin and the GABA agonist gaboxadol, making it a critical factor in determining drug bioavailability and potential drug-nutrient interactions [18, 19, 25].

Other names

Lysosomal amino acid transporter 1LYAAT1Solute carrier family 36 member 1hPAT1Proton/amino acid transporter 1

Proton-coupled symport of small neutral amino acids and amino acid-mimetic drugs from the lysosomal or intestinal lumen into the cytosol; activation of mTORC1 signaling via physical interaction with Rag GTPases (transceptor function).