| Function | Electrogenic Na(+)-coupled sugar symporter that actively transports myo-inositol and its stereoisomer scyllo-inositol across the plasma membrane, with a Na(+) to sugar coupling ratio of 2:1. Maintains myo-inositol concentration gradient that defines cell volume and fluid balance during osmotic stress, in particular in the fetoplacental unit and central nervous system. Forms coregulatory complexes with voltage-gated K(+) ion channels, allosterically altering ion selectivity, voltage dependence and gating kinetics of the channel. In turn, K(+) efflux through the channel forms a local electrical gradient that modulates electrogenic Na(+)-coupled myo-inositol influx through the transporter. Associates with KCNQ1-KCNE2 channel in the apical membrane of choroid plexus epithelium and regulates the myo-inositol gradient between blood and cerebrospinal fluid with an impact on neuron excitability. Associates with KCNQ2-KCNQ3 channel altering ion selectivity, increasing Na(+) and Cs(+) permeation relative to K(+) permeation. Provides myo-inositol precursor for biosynthesis of phosphoinositides such as PI(4,5)P2, thus indirectly affecting the activity of phosphoinositide-dependent ion channels and Ca(2+) signaling upon osmotic stress. |
| Protein Name | Sodium/Myo-Inositol CotransporterNa(+/Myo-Inositol CotransporterSodium/Myo-Inositol Transporter 1Smit1Solute Carrier Family 5 Member 3 |
| Database Links | Reactome: R-HSA-429593 |
| Cellular Localisation | Apical Cell MembraneMulti-Pass Membrane ProteinBasolateral Cell MembraneColocalizes With Kcnq1 At The Apical Membrane Of Choroid Plexus Epithelium |
| Alternative Antibody Names | Anti-Sodium/Myo-Inositol Cotransporter antibodyAnti-Na(+/Myo-Inositol Cotransporter antibodyAnti-Sodium/Myo-Inositol Transporter 1 antibodyAnti-Smit1 antibodyAnti-Solute Carrier Family 5 Member 3 antibodyAnti-SLC5A3 antibody |
Information sourced from Uniprot.org
