Linked Life Data

8227068

Source:http://linkedlifedata.com/resource/pubmed/id/8227068

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
33
pubmed:dateCreated
1993-12-20
pubmed:databankReference
pubmed:abstractText
An expression library from porcine kidney cortex was screened with a monoclonal antibody (R4A6) which stimulates high-affinity phlorizin binding in kidney and intestine but does not react with the membrane protein (SGLT1) which mediates Na(+)-coupled transport of D-glucose (Hediger, M.A., Coady, M.J., Ikeda, T.S., and Wright, E.M. (1987) Nature 330, 379-381). A cDNA (RS1) was obtained which codes for a hydrophilic M(r) 66,832 polypeptide and contains a predicted hydrophobic alpha-helix at the COOH terminus. After expression in Xenopus oocytes RS1 protein was found associated with the plasma membrane. RS1-homologous mRNAs were detected in renal outer cortex and outer medulla, small intestine, liver, and LLCPK1 cells, but not in skeletal muscle, heart muscle, Madin-Darby canine kidney (MDCK) cells, renal inner medulla, and Xenopus oocytes. After nondenaturing gel electrophoresis of renal brush-border membranes comigration of RS1- and SGLT1-homologous proteins as a high molecular weight complex was demonstrated. RS1 altered the expression of Na(+)-glucose cotransport by SGLT1 in Xenopus oocytes. There was no effect on the expression of the nonhomologous transporters for Na(+)-gamma-aminobutyric acid cotransport and for Na(+)-independent glucose transport. However, RS1 also changed the expression of the SGLT1-homologous Na(+)-myo-inositol cotransporter from MDCK cells. The Vmax of methyl-alpha-D-glucopyranoside (AMG) transport expressed after injection of a small amount of SGLT1-cRNA was increased 40-fold when a stoichiometric amount of RS1-cRNA was coinjected. In addition the voltage and glucose dependence of expressed AMG uptake and the concentration dependence of transport inhibition by phlorizin were changed when stoichiometric amounts of RS1-cRNA were coinjected with SGLT1-cRNA. Thus with SGLT1 one apparent transport site (K0.5 about 100 microM) and one apparent phlorizin inhibition site (Ki about 5 microM) was observed whereas with SGLT1 plus RS1 two apparent transport sites (K0.5(1) about 20 microM, K0.5(2) about 1 mM) and two apparent phlorizin inhibition sites (Ki(1) about 0.3 microM, Ki(2) about 30 microM) were found as has been described in brush-border membrane vesicles of kidney and intestine (see e.g. Koepsell, H., Fritzsch, G., Korn, K., and Madrala, A. (1990) J. Membr. Biol. 114, 113-132). The data suggest that the Na(+)-D-glucose cotransporter and possibly also other SGLT1-type Na(+)-cotransporters contain RS1-type regulatory subunits.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
268
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
25041-53
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:8227068-Amino Acid Sequence, pubmed-meshheading:8227068-Animals, pubmed-meshheading:8227068-Base Sequence, pubmed-meshheading:8227068-Biological Transport, pubmed-meshheading:8227068-Carrier Proteins, pubmed-meshheading:8227068-Cloning, Molecular, pubmed-meshheading:8227068-DNA, Complementary, pubmed-meshheading:8227068-Dogs, pubmed-meshheading:8227068-Glucose, pubmed-meshheading:8227068-Immunohistochemistry, pubmed-meshheading:8227068-Kidney, pubmed-meshheading:8227068-Membrane Glycoproteins, pubmed-meshheading:8227068-Membrane Proteins, pubmed-meshheading:8227068-Microvilli, pubmed-meshheading:8227068-Molecular Sequence Data, pubmed-meshheading:8227068-Monosaccharide Transport Proteins, pubmed-meshheading:8227068-Oocytes, pubmed-meshheading:8227068-RNA, Messenger, pubmed-meshheading:8227068-Sodium, pubmed-meshheading:8227068-Sodium-Glucose Transporter 1, pubmed-meshheading:8227068-Swine, pubmed-meshheading:8227068-Xenopus
pubmed:year
1993
pubmed:articleTitle
Cloning of a membrane-associated protein which modifies activity and properties of the Na(+)-D-glucose cotransporter.
pubmed:affiliation
Max-Planck-Institut für Biophysik, Frankfurt am Main, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't