title: Glucose transporters serve as water channels.
abstract: Water traverses the plasma membranes of some eukaryotic cells faster than can be explained by the water permeability of their lipid bilayers. This has led to a search for a water channel. Our previous work identified glucose transporters as candidates for such a channel. We report here that Xenopus laevis oocytes injected with mRNA encoding the brain/Hep G2, adult skeletal muscle/adipocyte, or liver forms of the glucose transporter exhibit an osmotic water permeability of their plasma membranes larger than that of untreated oocytes. The osmotic water permeability component attributable to glucose transporters increased an average of 4.8-fold in the injected oocytes. These studies provide direct evidence that the facilitative, sodium-independent mammalian glucose transporters serve as membrane water channels.
authors.affiliation: Department of Physiology, College of Physicians and Surgeons, Columbia University, New York, NY 10032.
authors.forename: J
authors.initials: J
authors.lastname: Fischbarg
authors.forename: K Y
authors.initials: KY
authors.lastname: Kuang
authors.forename: J C
authors.initials: JC
authors.lastname: Vera
authors.forename: S
authors.initials: S
authors.lastname: Arant
authors.forename: S C
authors.initials: SC
authors.lastname: Silverstein
authors.forename: J
authors.initials: J
authors.lastname: Loike
authors.forename: O M
authors.initials: OM
authors.lastname: Rosen
mesh_terms: D000818:Animals; D001834:Body Water / Q000378:metabolism*; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002463:Cell Membrane Permeability; D005260:Female; D006801:Humans; D007700:Kinetics; D008051:Lipid Bilayers; D008845:Microinjections; D009004:Monosaccharide Transport Proteins / Q000235:genetics / Q000378:metabolism*; D009865:Oocytes / Q000378:metabolism*; D010693:Phloretin / Q000494:pharmacology; D012333:RNA, Messenger / Q000008:administration & dosage / Q000235:genetics; D011972:Receptor, Insulin / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D014982:Xenopus laevis
chemical_list: D008051:Lipid Bilayers; D009004:Monosaccharide Transport Proteins; D012333:RNA, Messenger; D011972:Receptor, Insulin; D010693:Phloretin