Meta-Biol

• Pathways

The plasma membrane-associated transport protein SLC5A6 (aka sodium-dependent multivitamin transporter, SMVT) mediates the uptake of one molecule of biotin (Btn) and two sodium ions from the extracellular space to the cytosol. Limited Northern blotting studies suggest that SLC5A6 is widely expressed and abundant in placenta, liver and small intestine. SLC5A6 may thus play a central role in Btn uptake from dietary sources. SLC5A6 also mediates the uptake of pantothenate and lipoate (Prasad et al. 1999, Wang et al. 1999, Balamurugan et al. 2003). PDZ domain-containing protein 11 (PDZD11 aka AIPP1) is a cytosolic protein with a single PDZ domain which can bind to the C-terminal class 1 PDZ binding motif of SLC5A6, resulting in a significant induction of vitamin uptake over that with SLC5A6 alone (Nabokina et al. 2011).