SLC5A6 cotransports extracellular Btn and 2xNa+ to cytosol

Stable Identifier
Reaction [transition]
Homo sapiens
biotin [extracellular] + 2 Na+ [extracellular] => biotin [cytosol] + 2 Na+ [cytosol]
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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).

Literature References
PubMed ID Title Journal Year
10329687 Human placental Na+-dependent multivitamin transporter. Cloning, functional expression, gene structure, and chromosomal localization.

Wang, H, Leibach, FH, Xia, H, Ganapathy, V, Yang-Feng, TL, Huang, W, Devoe, LD, Prasad, PD, Fei, YJ

J Biol Chem 1999
21183659 Association of PDZ-containing protein PDZD11 with the human sodium-dependent multivitamin transporter

Said, HM, Nabokina, SM, Subramanian, VS

Am. J. Physiol. Gastrointest. Liver Physiol. 2011
12646417 Biotin uptake by human intestinal and liver epithelial cells: role of the SMVT system

Said, HM, Ortiz, A, Balamurugan, K

Am. J. Physiol. Gastrointest. Liver Physiol. 2003
10334869 Molecular and functional characterization of the intestinal Na+-dependent multivitamin transporter

Wang, H, Leibach, FH, Ganapathy, V, Huang, W, Devoe, LD, Prasad, PD, Fei, YJ

Arch Biochem Biophys 1999
Catalyst Activity

sodium-dependent multivitamin transmembrane transporter activity of SLC5A6:PDZD11 [plasma membrane]

Orthologous Events
Cross References
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