title: Fingerprints of hSGLT5 sugar and cation selectivity.
abstract: Sodium glucose cotransporters (SGLTs) mediate the translocation of carbohydrates across the brush border membrane of different organs such as intestine, kidney, and brain. The human SGLT5 (hSGLT5), in particular, is localized in the kidney were it is responsible for mannose and fructose reabsorption from the glomerular filtrate as confirmed by more recent studies on hSGLT5 knockout mice. Here we characterize the functional properties of hSGLT5 expressed in a stable T-Rex-HEK-293 cell line using biochemical and electrophysiological assays. We confirmed that hSGLT5 is a sodium/mannose transporter that is blocked by phlorizin. Li(+) and H(+) ions were also able to drive mannose transport, and transport was electrogenic. Our results moreover indicate that substrates require a pyranose ring with an axial hydroxyl group (-OH) on carbon 2 (C-2). Compared with Na(+)/glucose cotransport, the level of function of Na(+)/mannose cotransport in rat kidney slices was low.
authors.affiliation: Department of Physiology, Geffen School of Medicine, University of California, Los Angeles, California; and.
authors.forename: Chiara
authors.initials: C
authors.lastname: Ghezzi
authors.forename: Edurne
authors.initials: E
authors.lastname: Gorraitz
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Hirayama
authors.forename: Donald D F
authors.initials: DD
authors.lastname: Loo
authors.forename: Rolf
authors.initials: R
authors.lastname: Grempler
authors.forename: Eric
authors.initials: E
authors.lastname: Mayoux
authors.forename: Ernest M
authors.initials: EM
authors.lastname: Wright
mesh_terms: D000818:Animals; D002412:Cations; D057809:HEK293 Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007668:Kidney / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D008094:Lithium / Q000378:metabolism; D008358:Mannose / Q000378:metabolism*; D008564:Membrane Potentials; D015394:Molecular Structure; D010695:Phlorhizin / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012964:Sodium / Q000378:metabolism*; D051247:Sodium-Glucose Transport Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D014162:Transfection
chemical_list: D002412:Cations; C000589047:SLC5A10 protein, human; D051247:Sodium-Glucose Transport Proteins; D008094:Lithium; D012964:Sodium; D010695:Phlorhizin; D008358:Mannose
keywords: SGLT5; kidney; mannose