Pyridoxine transporter

Pyridoxine transporters are a specialized group of solute carrier (SLC) proteins that facilitate the movement of vitamin B6 (pyridoxine) across plasma and organellar membranes. Key human transporters include SLC19A3 (thiamine transporter 2), which mediates intestinal absorption and blood-brain barrier transport, and SLC49A4 (DIRC2), which serves as a lysosomal exporter to regulate intracellular B6 availability [1.3.2, 1.3.5]. These proteins are essential for maintaining the homeostasis of vitamin B6, a vital cofactor for over 140 enzymatic reactions, including the synthesis of neurotransmitters like GABA and serotonin [1.4.1, 1.4.5]. Clinical interest in these transporters has grown due to their role in drug-nutrient interactions, where medications such as metformin and fedratinib can inhibit transport, potentially leading to deficiency [1.2.4, 1.3.3]. Conversely, excessive pyridoxine intake or impaired transport can result in sensory peripheral neuropathy, a hallmark of B6 toxicity [1.4.4, 1.4.5]. Understanding these transporters is crucial for managing metabolic disorders, preventing drug-induced neuropathies, and optimizing vitamin supplementation therapies.

Other names

Vitamin B6 transporterSolute carrier family 19 member 3 (SLC19A3)Solute carrier family 49 member 4 (SLC49A4)Thiamine transporter 2 (THTR-2)Disrupted in renal carcinoma 2 (DIRC2)Solute carrier family 19 member 2 (SLC19A2)Thiamine transporter 1 (THTR-1)

Proton-coupled transport of pyridoxine vitamers across the plasma and organellar membranes.