Involved in the sodium-dependent cotransport of myo-inositol (MI) with a Na(+):MI stoichiometry of 2:1 (, ). Exclusively responsible for apical MI transport and absorption in intestine (By similarity). Can also transport D-chiro-inositol (DCI) but not L-fucose (, ). Exhibits stereospecific cotransport of both D-glucose and D-xylose (By similarity). May induce apoptosis through the TNF-alpha, PDCD1 pathway (, ). May play a role in the regulation of MI concentration in serum, involving reabsorption in at least the proximal tubule of the kidney (By similarity).
Subcellular locations: Membrane, Apical cell membrane
Located on apical membrane of enterocytes (By similarity). Located on membrane of kidney brush border membrane vesicles (BBMVs) and apical membrane of proximal convoluted tubules (By similarity).
Highest expression in heart, skeletal muscle, kidney, liver and placenta. Weaker expression in brain, colon, spleen, lung and peripheral blood leukocytes.