Linked Life Data

21325825

Source:http://linkedlifedata.com/resource/pubmed/id/21325825

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2011-2-17
pubmed:abstractText
The glutamine transporter SNAT3 (SLC38A3), which also transports asparagine and histidine, exchanges sodium for protons, and displays a non-stoichiometrical conductance, which is suppressed by the catalytic activity of carbonic anhydrase II (CAII). In this study, we show that this conductance of rat SNAT3, expressed in Xenopus oocytes, is also suppressed following co-expression with CAI, CAIII, CAIV, and CAII-H64A (mutant with impaired intramolecular H(+) shuttling). All CA isoforms and the CAII mutant displayed catalytic activity in intact oocytes, although in vitro studies had reported only very low catalytic activity of CAIII and CAII-H64A. The CA-mediated suppression of conductance was only observed, however, when glutamine, but not when asparagine, was the substrate. We hypothesized that this substrate specificity of the CA action might be due to the different ion selectivity induced by the different amino acid substrates, which induce currents carried by sodium and/or protons. The ion selectivity and conductance was dependent on both pH and extracellular sodium concentration for glutamine and asparagine; however the sodium dependence of the conductance, when asparagine was the substrate, was significantly greater at higher sodium concentrations, which might explain the difference in the sensitivity of the conductance to CAs. Given the presence of CAs in most cells, substrate sensing of SNAT3 would be indicated by different membrane potential changes.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1421-9778
pubmed:author
pubmed:copyrightInfo
Copyright © 2011 S. Karger AG, Basel.
pubmed:issnType
Electronic
pubmed:volume
27
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
79-90
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Substrate-dependent interference of carbonic anhydrases with the glutamine transporter SNAT3-induced conductance.
pubmed:affiliation
Abteilung für Allgemeine Zoologie, FB Biologie, University of Kaiserslautern, Kaiserslautern, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't