Sodium Dependent Multivitamin Transporter (SMVT)

The predicted protein contains 12 putative transmembrane domains with the N and C termini facing the cytoplasm. SMVT has homology to other known sodium-dependent nutrient transporters, including bacterial pantothenate permeases and mammalian iodide transporter, glucose transporter-1 and -2, and myoinositol transporter. When expressed in HeLa cells, SMVT induced sodium gradient-dependent uptake of pantothenate, biotin, and lipoate. The functional characteristics of the induced activity were similar to those of placental pantothenate/biotin transport. Northern blot analysis revealed that the SMVT gene was expressed in all rat tissues tested, suggesting that this protein may be involved in the entry of pantothenate, biotin, and lipoate in all cell types.