Solute carrier family 19 member 3 (Thiamine transporter 2) (SLC19A3)

Solute carrier family 19 member 3 (SLC19A3), also known as Thiamine transporter 2 (THTR2), is a transmembrane protein that facilitates the high-affinity, pH-dependent uptake of thiamine (vitamin B1) into cells (UniProt: Q9BZV2). It is primarily expressed in the small intestine, kidneys, and brain, where it plays a critical role in maintaining thiamine homeostasis (PubMed: 11893754). Mutations in the SLC19A3 gene are the underlying cause of biotin-thiamine-responsive basal ganglia disease (BTBGD), a severe neurometabolic disorder characterized by subacute encephalopathy and bilateral basal ganglia lesions (OMIM: 606152). THTR2 is also a target of pharmacological interest because its inhibition by certain drugs, such as the JAK2 inhibitor fedratinib or the antidiabetic agent metformin, can lead to drug-induced thiamine deficiency and Wernicke-like encephalopathy (PubMed: 24056317, 26206454). Consequently, THTR2 is a key factor in both genetic metabolic diseases and the prediction of adverse drug reactions related to vitamin B1 transport. The transporter is also being explored for its role in the delivery of thiamine-conjugated prodrugs to improve bioavailability (PubMed: 22403136).

Other names

Thiamine transporter 2THTR2THTR-2Solute carrier family 19 member 3SLC19A3Thiamine metabolism dysfunction syndrome 2

Mediates high-affinity thiamine transport; inhibited by small molecules like fedratinib and metformin.