Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
Characterization of a Na+/glucose cotransporter cloned from rabbit small intestine.
Ikeda TS
,
Hwang ES
,
Coady MJ
,
Hirayama BA
,
Hediger MA
,
Wright EM
.
Abstract
The Na+/glucose cotransporter from rabbit intestinal brush border membranes has been cloned, sequenced, and expressed in Xenopus oocytes. Injection of cloned RNA into oocytes increased Na+/sugar cotransport by three orders of magnitude. In this study, we have compared and contrasted the transport properties of this cloned protein expressed in Xenopus oocytes with the native transporter present in rabbit intestinal brush borders. Initial rates of 14C-alpha-methyl-D-glucopyranoside uptake into brush border membrane vesicles and Xenopus oocytes were measured as a function of the external sodium, sugar, and phlorizin concentrations. Sugar uptake into oocytes and brush borders was Na+-dependent (Hill coefficient 1.5 and 1.7), phlorizin inhibitable (Ki 6 and 9 microM), and saturable (alpha-methyl-D-glucopyranoside Km 110 and 570 microM). The sugar specificity was examined by competition experiments, and in both cases the selectivity was D-glucose greater than alpha-methyl-D-glucopyranoside greater than D-galactose greater than 3-O-methyl-D-glucoside. In view of the close similarity between the properties of the cloned protein expressed in oocytes and the native brush border transporter, we conclude that we have cloned the classical Na+/glucose cotransporter.
BARRY,
ELECTRICAL POTENTIALS ASSOCIATED WITH INTESTINAL SUGAR TRANSFER.
1964, Pubmed
BARRY,
ELECTRICAL POTENTIALS ASSOCIATED WITH INTESTINAL SUGAR TRANSFER.
1964,
Pubmed
Brot-Laroche,
Temperature sensitivity and substrate specificity of two distinct Na+-activated D-glucose transport systems in guinea pig jejunal brush border membrane vesicles.
1986,
Pubmed
Brot-Laroche,
Characterization of the D-glucose/Na+ cotransport system in the intestinal brush-border membrane by using the specific substrate, methyl alpha-D-glucopyranoside.
1987,
Pubmed
CRANE,
Intestinal absorption of sugars.
1961,
Pubmed
Hediger,
Expression of size-selected mRNA encoding the intestinal Na/glucose cotransporter in Xenopus laevis oocytes.
1987,
Pubmed
,
Xenbase
Hediger,
Expression cloning and cDNA sequencing of the Na+/glucose co-transporter.
1987,
Pubmed
,
Xenbase
Honegger,
Further evidence for the multiplicity of carriers for free glucalogues in hamster small intestine.
1974,
Pubmed
Kaunitz,
Kinetics of sodium D-glucose cotransport in bovine intestinal brush border vesicles.
1984,
Pubmed
Kimmich,
Sodium-sugar coupling stoichiometry in chick intestinal cells.
1984,
Pubmed
Kimmich,
alpha-Methylglucoside satisfies only Na+-dependent transport system of intestinal epithelium.
1982,
Pubmed
Peerce,
Sodium-induced conformational changes in the glucose transporter of intestinal brush borders.
1984,
Pubmed
Restrepo,
Kinetic analysis of mechanism of intestinal Na+-dependent sugar transport.
1985,
Pubmed
Schultz,
Coupled transport of sodium and organic solutes.
1970,
Pubmed
Stevens,
Multiple transport pathways for neutral amino acids in rabbit jejunal brush border vesicles.
1982,
Pubmed
Wright,
Sugar uptake by intestinal basolateral membrane vesicles.
1980,
Pubmed
